Saturday, September 24, 2011

Humans on a Cafeteria Diet

In the 1970s, as the modern obesity epidemic was just getting started, investigators were searching for new animal models of diet-induced obesity.  They tried all sorts of things, from sugar to various types of fats, but none of them caused obesity as rapidly and reproducibly as desired*.  1976, Anthony Sclafani tried something new, and disarmingly simple, which he called the "supermarket diet": he gave his rats access to a variety of palatable human foods, in addition to standard rodent chow.  They immediately ignored the chow, instead gorging on the palatable food and rapidly becoming obese (1).  Later renamed the "cafeteria diet", it remains the most rapid and effective way of producing dietary obesity and metabolic syndrome in rodents using solid food (2).


A few weeks ago, I was paging through Dr. David Kessler's book The End of Overeating, when I came across a citation for a paper with an extraordinary title: "Spontaneous Overfeeding with a 'Cafeteria Diet' in Men: Effects on 24-hour Energy Expenditure and Substrate Oxidation."  Further research revealed two more related papers, all from the research group of Dr. Eric Ravussin, who has dome some excellent work on energy balance, fat/carbohydrate/protein oxidation, and obesity (e.g, 3). 

The first study was published in 1992 (4), and seems initially to have simply been an attempt to design a novel way of accurately measuring food intake in free-living humans, which is notoriously difficult.  Investigators created an "automated food-selection system" consisting of two large vending machines filled with a variety of prepared foods of known calorie and nutrient compositions.  They recruited ten lean, healthy men.  At the beginning of the experiment, the investigators took four days to determine each volunteer's energy requirement for weight maintenance.  Then, in the setting of a metabolic ward where no other food was available, the volunteers were allowed to select and eat as much food as they pleased from the vending machines over seven days.  The foods available included English muffins, French toast, pancakes with syrup, scrambled eggs, chicken pie, cheeseburgers, margarine, white sugar, various cakes and puddings, apples, jelly beans, Doritos, M and M's, apple juice, 2% milk, sodas and several other foods.

I doubt the investigators were prepared for what they observed when they turned the ten men loose on those vending machines.  They immediately began consuming excessive calories, an average of 1,544 kcal per day in excess of their previously determined energy needs (with a fairly typical macronutrient composition by percentage).  That amounts to a roughly 60% increase in calorie intake over baseline, a striking change, particularly since it was completely voluntary.  Over the course of seven days, the volunteers gained an average of 5.1 lb (2.3 kg). 

The next two studies used a similar design and were both published in 1995.  One notable difference is that they were conducted in male and female Pima Indians, a population with a high susceptibility to obesity upon adopting an industrial diet/lifestyle.  Another difference is that these studies were conducted with a larger number of volunteers of various degrees of fatness.

The next study, whose title I mentioned above, was in Pima men (5).  After determining the volunteers' energy needs for weight maintenance, they set them loose on vending machines full of "familiar, palatable foods."  Over the course of the next five days, they consumed an excess of 1,637 kcal per day, a 56% increase over baseline.  33 volunteers out of 34 overate relative to baseline, including both lean and obese individuals, resulting in an average weight gain of 2 lbs (0.9 kg). 

The third and final study was in Pima women (6).  The design of this study was essentially the same as above.  The women overate by an average of 27% and gained 0.9 lbs (0.4 kg) over five days. The obese women consumed more calories, proportionally more fat, and gained more than twice as much body fat as the lean women.


Main Points

There are a few interesting things that can be gleaned from these studies:
  1. Just as in rats, exposing humans to a variety of readily accessible, energy dense, palatable foods causes excessive food intake and rapid weight gain.  The degree of overeating varies by individual, but nearly everyone overeats to some degree.  Whatever the mechanism(s) underlying this may be, the phenomenon has important implications for the commercialization of food and the associated obesity epidemic in affluent nations.
  2. In most cases, changes in body fatness are primarily, but not exclusively, the result of changes in energy intake. This is a consistent finding across many studies.  The obesity epidemic in the US has corresponded with a large increase in daily calorie intake, and also a substantial increase in energy expenditure, because larger bodies burn more energy.  Thus, energy "flux" has increased by roughly 400 kcal/day in the US since the 1970s (3).  
  3. When energy intake is increased, energy expenditure also rapidly increases, although over the time scale of these studies it was not nearly sufficient to balance out the extra energy intake.
  4. When a diet of mixed macronutrient composition is eaten to excess, the carbohydrate is preferentially burned off, while the fat is mostly shunted into fat tissue.  This makes sense, because why would the body go through the inefficient process of converting carbohydrate to fat for storage when it can just shunt dietary fat directly into fat tissue?  This does not imply that dietary fat is fattening under conditions of energy balance. 
  5. Under the conditions of the experiment, obese Pima women spontaneously ate more calories and selected food with a higher fat and lower carbohydrate content than lean Pima women.  They also gained more than twice as much fat mass on average, perhaps pointing to differences underlying obesity susceptibility between individuals.  I believe this is similar to other observational findings on the subject.  

*High fat diets, particularly in combination with refined starches and sugars, were among the most effective.  The composition of these diets has been refined since then, and modern "purified" high-fat diets reliably induce obesity in susceptible strains of rodents.  The most commonly used diet is Research Diets D12492, which is 60% fat by calories, and composed mostly of lard, soybean oil, casein, maltodextrin, sucrose and cellulose (7).  It tastes kind of like raw cookie dough, and the rats are crazy about it.

143 comments:

Canibalinho said...

This post has good info, but suggesting the fat is stored as fat is absolutely wrong and is bad science. You have finally lost me as a subscriber. Its the sugars, my friend. Without them, there is no 'cafeteria diet.'

Paleo Phil said...
This comment has been removed by the author.
Ben Greenfield said...

I'm not sure I understand Canibalinho's response. In the presence of excess calorie intake, wouldn't BOTH sugars and fats be stored as fat?

Paleo Phil said...

Stephan, do you think that the human body fat produced by eating natural wild foods, such as wild ruminant fat depots and wild fatty fish and wild fruits, is as unhealthy as that produced by industrial foods like hydrogenated vegetable oils and refined sugar (as in cookie dough) and has this ever been investigated? I suspect that all body fat is not equally bad and I suspect that you might agree.

One reason I suspect this is that traditional peoples tend to regard body fat as wonderful, especially on fertile women, rather than unhealthful. I wonder if the modern obsession with thinness rather than overall health is contributing to the problem rather than the solution.

Christopher said...

I'm a huge fan of the Food Reward Hypothesis and have really enjoyed your posts on the subject. This line sticks out to me though:

"When energy intake is increased, energy expenditure also rapidly increases, although over the time scale of these studies it was not nearly sufficient to balance out the extra energy intake."

I would expect that if the set point is increased (above current fat mass) that intake would increase and/or expenditure would decrease. You spoke to this in a previous post in which rats eating a calorie-restricted cafeteria diet gained almost as much weight as rats eating the cafeteria diet ad libitum.

I realize that one typically has a higher bmr at a higher body weight, but I wouldn't expect the bmr to elevate until the body fat mass is at/above set point - one possible explanation for the "overshoot" seen on reducing diets.

What am I missing here?

Don said...

Canibalinho,

Do you think excess fat is stored as carbohydrate or protein?

If you think Stephan has bad science, then please provide some good science to back your implication that fat is not stored as fat.

Check those cafeteria items and you will find that without fat, there is no cafeteria diet.

Stephan,

Excellent. So many studies clearly show that excess CHO is preferentially stored as glycogen or disposed by thermogenesis, and not stored as adipose, that it is beyond question now. This is in part why you don't find obesity among the Kitavans. It is simply difficult to eat enough CHO to cause lipogenesis if the diet is otherwise low in fat.

psychic24 said...

I love when Don Matesz makes an appearance, always with his critique's that are always so wrong. I'm sorry, i don't mean to be mean, but every time i read something authored by Don it's almost always wrong. Increased thermogenesis yielded by turning carbs into fat has to do with when you eat under hypercaloric conditions; something which i doubt the kitavan's do, seeing as how their weight remains stable/only goes down as they age (due to muscle atrophy).

Great post, Stephan, waiting anxiously for the next (and the one after that ) =)

Kurt G. Harris MD said...

@ Stephan

Fascinating. Did the cafeteria diet investigators ever postulate that the "solution" of feeding it to the rats may itself explain the phenomenon they are investigating - obesity?

I'll have to look at those papers....


@Ben

Yes

If you are eating in caloric excess, there is net fat gain.

It matters not a jot whether you are eating high fat or high carb.

High fat -The glucose is preferentially disposed of first, then fatty acids are used until energy needs are met. The excess fatty acids are then stored as fat.

High carb - the glucose is still disposed of first. If energy need are all met with glucose, then all the fat and the "unused" glucose end up as fat.

The above ignores structural needs but is fundamentally true.

The lack of obesity in Kitavans has nothing to do with whether they eat high carb or not. Food quality is the issue.

Nutrient fates at the margin depend on energy balance.

Dregs said...

Canibalinho,

Is what is needed to "keep you as a subscriber" to keep repeating things you already agree with? Then why do you read in the first place since it sounds like you already know everything you will ever accept as true?

Even if Stephen is wrong (which I am not qualified to judge, and I doubt you are either), offer arguments against what he has said or point out the flaws.

This is science, not religion.

berto said...

Dr. Guyenet,

"Just as in rats, exposing humans to a variety of readily accessible, energy dense, palatable foods causes excessive food intake and rapid weight gain. The degree of overeating varies by individual, but nearly everyone overeats to some degree. Whatever the mechanism(s) underlying this may be, the phenomenon has important implications for the commercialization of food and the associated obesity epidemic in affluent nations."

I like that you said, "whatever the mechanism".

"In most cases, changes in body fatness are primarily, but not exclusively, the result of changes in energy intake. This is a consistent finding across many studies. The obesity epidemic in the US has corresponded with a large increase in daily calorie intake, and also a substantial increase in energy expenditure, because larger bodies burn more energy. Thus, energy "flux" has increased by roughly 400 kcal/day in the US since the 1970s (3)."

You said, "the result of changes in energy increases", but couldn't this be: changes in food choices, leads to increase in fat mass, which leads to increase in energy needs? This could be what happened.

"When energy intake is increased, energy expenditure also rapidly increases, although over the time scale of these studies it was not nearly sufficient to balance out the extra energy intake."

Fair enough.

"When a diet of mixed macronutrient composition is eaten to excess, the carbohydrate is preferentially burned off, while the fat is mostly shunted into fat tissue. This makes sense, because why would the body go through the inefficient process of converting carbohydrate to fat for storage when it can just shunt dietary fat directly into fat tissue? This does not imply that dietary fat is fattening under conditions of energy balance."

While this may be true, you do not know it as fact (or do you). Why else would you follow with, "this makes sense"? However, this does follow anecdotal evidence, even if it is just the few hundred that I have worked with - I mean the part about gaining fat mass, not necessarily what is shuttled where.

"Under the conditions of the experiment, obese Pima women spontaneously ate more calories and selected food with a higher fat and lower carbohydrate content than lean Pima women. They also gained more than twice as much fat mass on average, perhaps pointing to differences underlying obesity susceptibility between individuals. I believe this is similar to other observational findings on the subject."

While this is an obvious stab at Taubes, were the women who choose higher fat, lower carb diets already obese; and if so, what were the actual ratios? Does this say anything about their respective state of broken metabolisms, and the resulting possibilities?

I may have never said so, but I appreciate your hard work and talents.

-Al

Alan said...

>>> One reason I suspect this is that traditional peoples tend to regard body fat as wonderful, especially on fertile women, rather than unhealthful. I wonder if the modern obsession with thinness


I do not buy the story that we today have radically different body-image mentalities.

Anyone who starts an agricultural (to include pastoralism) life, is no longer a "traditional" human being.

Our current admiration for sleek builds was not implanted into us by Martian invaders in the past 100 years. We evolved this preference ourselves, using our traditional evolved brains.

Bill Strahan said...

There is another aspect of a metabolic ward study: Boredom.

When I'm in my native environment, I'm busy building airplanes, working on one business or another, running errands with and for the kids...I'm just plain busy. Food ends up crossing my mind infrequently, and most of the time my first meal of the day is my post-workout meal in the evening.

If you took me out of that environment, where there were no tasks to which I was accustomed, no lists of things I need to do, I tend to think I'd be bored enough that food alone would provide some level of stimulation and I'd eat a lot in that setting.

I don't think that explains it all, especially since the rat study eliminates the boredom/busy aspect since I assume they were stuck in cages under both diets. But for humans, we have a clear desire to use food as entertainment. If I'm isolated from my normal tasks and stuck in a room with vending machines, it's just a matter of time.

Anon said...

Why do I have the feeling that they would have eaten less if the food had been left out in a pile?

I think the feeling that the subjects got that they were raiding vending machines for free might have been a significant confounder.

Galina L. said...

@ Don
"It is simply difficult to eat enough CHO to cause lipogenesis if the diet is otherwise low in fat."

I hope you just got carried away . A lot of people got fat on a fat-free things like yogurts, bread with jam, cereals.

revelo said...

This certainly confirms my own experience with how to control weight. Keep the scrumptuous processed foods out of the house and stock only boring staples in the cupboards: oats, rice, potatoes, canned salmon, olive oil and vinegar, salad vegetables, herb tea. Supplement by walking a mile to the store each day, buying two candy bars there, consume the candy immediately, return home, where there is nothing to eat at home but those boring unprocessed foods.

tilmon said...

That vending machine food is nothing I would call palatable. Under normal circumstances, I'd prefer the scrambled eggs over anything, but not out of a vending machine. I'd be avoiding them as assiduously as I avoid the hot dogs at a convenience store. And the same goes for the other erstwhile hot foods.

Rather than a cafeteria diet, these participants were subject to a food desert diet. It's exactly the sort of food you are stuck with whether in a low income area or an office building. It may be tasty in some ways, but it never actually feels like food.

pablo DLS said...
This comment has been removed by the author.
Nora said...

Call this the 'cruise diet'. Palatable food, available around the clock without effort of preparation and all-you-can-eat. A 5-lb weight gain guaranteed.

Mrs. Ed said...

Great post.I know there is the "big" debate between you and Taubes. I don't think anyone really has the answer yet but if you both leep digging we'll at least get interesting info. The only thing that really stands out to me is the cafeteria diet has the modern foods (the french toast, m&m's, etc). It would be interesting to see the same study with vegetables, wild seafood and game, and possibly some whole grains. No processed carbs or fats. Any food that comes from a box sets my radar off.

Evelyn aka CarbSane said...

@psychic, what did Don say that was wrong? I'm presuming that he's referring to accumulating fat tissue when he says "lipogenesis". In humans, de novo lipogenesis is not a major contributor to stored fat. Indeed if we overeat high carbs, we gain less than if we overeat high fat. Even when upregulated, DNL is a matter of a few grams of fat. Storing carbs as fat is inefficient as DNL is an energy requiring process. Furthermore, in Fat Futile-Cycling from Carb Excess, I discussed a study demonstrating that muscle cells handle carb excesses by DNL and subsequent oxidation of the fat. Some of the carb calories are wasted again in this process.

@Galina: I doubt that's a typo from Don and I agree with his statement. It is very hard, probably next to impossible, to get fat on a low fat diet unless, I suppose, one has a 2L/day Coke habit to go with. And let's be clear that a diet is not really low fat until you get down to 20% or below in fat calories. The SAD is not a low fat diet.

It sounds like Canibalinho is a student of the woefully misguided Nora "all body fat comes from glucose" Gedgaudas. I suggest he learn some basics of human physiology. Perhaps Nutrient Fates might be a place to start.

psychic24 said...

@carbsane

Not trying to be mean, but did you even read my comment? Clearly you didn't see the word hypercaloric--like when i stated there is increased thermogenesis in carbs vs fat under hypercaloric conditions. I was stating that the fact kitavans are skinny has nothing to do with carbs increased thermogenesis effect during DNL since they don't overeat.

Evelyn aka CarbSane said...

@psychic: You seem to preface a lot of your comments with "not trying to be mean". Usually that's a way of saying I'm being mean but I don't want you to think I am ;-)

Anyway, yes I did read your comment and mine stands. I do not see any error in Don's comment, and I linked to the futile cycling post that is evidence of this thermogenesis. That humans can thrive on an upwards of 80% carb diet while still burning a significant proportion of fat for fuel obligates some conversion between the two. It seems to occur more at the point of fuel usage (e.g. inside skeletal muscle cells) than we've previously thought.

Don was responding to Canibalinho who thinks Stephan is an idiot for suggesting that fat is stored as fat.

Daniel said...

I guess this is what accounts for freshmen weight gain in college... Kids switch from eating from their home kitchens to eating in an all-you-can-eat buffet.

Evelyn aka CarbSane said...

@Mrs. Ed: It would be interesting to see the same study with vegetables, wild seafood and game, and possibly some whole grains. No processed carbs or fats.

That's sort of the whole point of the CAF diet. It's not the macronutrients or the hormonal response they elicit (e.g. insulin) that makes you fat. It's the type of foods you are likely to overeat consistently that does. Interestingly, the macro ratios are bordering on "low carb" (usually around 40%) by recommended guidelines.

nothing91 said...

"It is simply difficult to eat enough CHO to cause lipogenesis if the diet is otherwise low in fat."

LOL.

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Swede said...

>>>"It is simply difficult to eat enough CHO to cause lipogenesis if the diet is otherwise low in fat."

LOL.
<<<

I love how everyone thinks that the low-fat diet they used to eat is what made them fat.

Get over it.

You ate crap food and that made you fat. As Dr. Harris said earlier, food quality is the issue.

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psychic24 said...

@carbsane

alrighty lol, gonna respond to everything i can. 1) you're totally correct about the mean thing, was kinda hoping i'd get to say it once more before you (or anyone) reacted =P .
2) Time to quote some stuff.
"In humans, de novo lipogenesis is not a major contributor to stored fat"

if the human we're discussing is gaining weight eating a high carb diet, then i'm kinda thinking DNL is a big contributor.

"Even when upregulated, DNL is a matter of a few grams of fat"

Extremely general statement. Are you refering to one normal sized meal, a week of meals, months, or one huge meal..etc

And in regard to Don's comment, i don't understand why you can't see that he's completely wrong…
I'll quote.
"This is in part why you don't find obesity among the Kitavans. It is simply difficult to eat enough CHO to cause lipogenesis if the diet is otherwise low in fat."

We obviously know that people on low fat diets in america have had some problems with fat gain, so that negates his statement, and even if he was to refine it to say carbs from whole foods, we have Stephan's prior post on a 37 pound (or so) weight gain from eating mainly sorghum and other dull starchy foods. Understandably it's difficult, as he says, but people would have just as much difficulty eating that much high fatty food (the whole foods kind)~and if we lay any credibility the mechanism of leptin signaling, then, even though fat gain may be greater eating a high fat diet, eventually the fat gain should equalize itself to that of the high carb diet. Laying a solid foundation to disagree with Don's statement about the kitavan's freedom from obesity attributed to the "simply difficult to eat enough CHO" theory he states.

Btw, i read your futile cycling post--good stuff. But what's really cool is that it lays the groundwork for some of the purported benefits of intermittent fasting. All the studies about intermittent fasting have included carbs ( at least the one's i could find), and the fact that since you not trying to reduce calories in these experiments, rather just trying to space your meals out, you have to eat more food in one sitting; this can lead to, theoretically, increased DNL from the excess carbs and more thermogenesis than eating more often.

brec said...

What is there to to in a metabolic ward other than eat and (probably) watch TV?

Was there a control ward with a different selection in the vending machines?

brec said...

"What is there to to" -> "What is there to do"

Evelyn aka CarbSane said...

@psychic: I disagree with this:
"We obviously know that people on low fat diets in america have had some problems with fat gain"

Americans have gotten fat on the SAD "cafeteria" diet that is the subject of this post. Not on a low fat diet. We've supposedly reduced our fat consumption, but that's not true. We've actually increased it slightly while increasing carbs more, so that as a % it's gone down ever so slightly -- still nowhere near "low fat" ranges akin to those of the Kitivans or Pritikins ;-)

I'm betting most who claim to get fat on low fat weren't eating low fat -- as a percentage or in absolute amounts -- at all.

I linked to the Nutrient Fates post in lieu of citing a bunch of references. The de novo lipogenesis label on my blog also has many relevant posts.

I'm not getting your point I guess. That's OK. I don't want to clutter Stephan's comments more with this. I just really didn't get your comment about Don mostly. His comment seems pretty sound to me.

Evelyn aka CarbSane said...

@psychic: BTW regarding IF and that futile cycling thing, I think the glycogen depletion of the fast would short circuit this -- any immediate excesses go into glycogen first before DNL.

psychic24 said...

@carbsane

yea that's why i said theoretically, depending on many factors, such as individual differences in carb/fat burning throughout the day, rate of gluconeogenesis,etc..

Greensmu said...

"In most cases, changes in body fatness are primarily, but not exclusively, the result of changes in energy intake."

Maybe it seems that way because we're looking at metabolic ward study's That last five days?

How are they going to gain weight in any other way in that short time frame?

Scott Miller said...

When you consume these nutritionally lacking so-called cafeteria foods, the body will naturally strive to intake the missing nutrients via continued eating.

I've said for years that any diet that requires you to count calories is a bad diet, because when you eat the right foods, hunger (or over-eating) becomes a non-issue. In fact, it's very hard to over-eat when you eat nutritionally dense foods that cover all the required bases.

The Palatable Food Hypothesis, IMO, is already well known. We already know that gluten has addictive qualities by activating opioid receptors in the brain. And we already know that eating low-nutrition foods results in hunger much sooner than high-nutrtion foods.

IMO, your Palatable Food Hypothesis should be redirected to a Nutritional Food Hypothesis, because it's a food's nutritional density that significantly determines eating habits.

Binko Barnes said...

My personal belief is that the body has a finely tuned sense of the nutrients it needs. Eat food that is low in nutrients and the body will keep sending signals to eat more.

I'm not so sure that high fat, low fat, high carb, low carb, high protein or low protein are really the most significant factors. Yet people stake out a position for some arbitrary level of these macro-nutrients and debate their position with religious fervor.

Sure, Jack In The Box sells pseudo-food that is engineered for maximum palatablity. But if your body is signalling you that you are truly satiated then you will just drive on by. The problem is that most people, no matter if they subscribe to the low fat or high fat, low carb or high carb doctrine are living in a state of nutrient deficiency. This is what drives them to junk food. Even if superficially "full" the body still compels them to continue eating because it is lacking in essential nutrients.

In the case of these studies the "cafeteria food" will leave people with a constant desire to eat more since it's almost impossible to satisfy the bodies nutrient needs on such stuff. The degree of fat or carb or protein is really not significant.

Rob A said...

Binko,

Good comment. I read in Acres magazine, I think, about the decline in various nutrients in our food relative to several generations ago. Seems plausible to me that our feedback mechanism might kick in and compel us to eat hyper-caloric diets if they are providing only adequate or even sub-adequate nutrient content relative to what we need. Perhaps that is a factor in susceptibility to obesity- internal nutrient stores that allow some to not overeat in an attempt to meet demands on an increasingly empty tank.

The change in farming practices has happened largely concurrent to the change in food palatability, and may be even directly tied to it. As high-brix gardeners maintain, really nutrient dense food tastes fantastic and industrial foods barely compare. But nutrient poor foods taste lousy and maybe need to be 'dolled up' by enhancing palatability through modern means to be tolerable. As one writer puts it:
'Children who give an average response to average food will give a GOOD response to GOOD food because IT TASTES SO GOOD.' ( www.crossroads.ws/brixbook/BBook.htm )

And as Michael Miles of Nutrition and Physical Regeneration points out regularly, one of the key and overlooked chapters in Weston Price's book is 'Food is Fabricated Soil Fertility.' Healthy soil produces healthy nutrient rich food which in turn produces healthy people. Absent healthy soil, it's perhaps no surprise that ill health is so rampant these days.

Stephan,
Are you aware of any research about the role of nutrient density of food and its relation to obesity, or susceptibility to it?

Taylor said...

You can eat a low-fat diet, and gain bodyfat on that diet, and still have the vast majority of the gained bodyfat come from the fat that you eat.

If you are on a low-fat diet but you are consuming more calories than you are expending then the carbs that you eat will be used to supply all the energy that you need and the fat the you eat, even if it is only 20% of your calorie intake will be stored as fat. 20% of total intake is still plenty to store lots of bodyfat.

Having explained this let me be clear that I agree with Carbsane that 99% of the people in this country that have gained weight have not done it on a low-fat diet. Low-fat food is not all that palatable even if there is plenty of sugar and salt in it. People gain weight trying to stick to low-fat diets because they are very difficult to stick to which is because low-fat food sucks!

psychic24 said...

@Binko "The problem is that most people, no matter if they subscribe to the low fat or high fat, low carb or high carb doctrine are living in a state of nutrient deficiency. This is what drives them to junk food. "

Not completely sure why it drives them to junk food. If it was nutrients they were lacking, wouldn't they be more prone to binge on veggies or liver? I think being driven to junk food is more of a "need more calories" issue.

"In the case of these studies the "cafeteria food" will leave people with a constant desire to eat more since it's almost impossible to satisfy the bodies nutrient needs on such stuff. "

A nice theory, but I favor food reward much more. My case is simple: eat a healthy, nutritious dinner (or whatever) and you're full, someone offers you more potatoes, liver.etc-you decline, someone offers you chocolate cake-you accept.

Evelyn aka CarbSane said...

@Scott Miller: "I've said for years that any diet that requires you to count calories is a bad diet, because when you eat the right foods, hunger (or over-eating) becomes a non-issue. "

The internet is littered with folks who got fatter eating the "Nourishing Traditions" way.

gallier2 said...

If the stored fat was only of dietary origin, its fatty acid composition would reflect exactly the dietary one. It mainly does not.

http://www.ncbi.nlm.nih.gov/pubmed/6017005

The interesting part is the proportion of MC to LC fatty acid. Medium chain fatty acid (lauric, myristic and myristoleic acids) are afaik not synthesizable by our metabolism. So the content of them in adipose tissue can only be sourced from diet (milk cream, coconut and palmoil are the main sources). The fattier the people were in that study, the less MCFA they had in proportion to LCFA. If the fat came only from diet, the proportions would stay the same.

Furthermore, regardless of that study, when glycogen stores are replete, every molecule of fructose is transformed to fat, there is no other pathway to dispose of it. In presence of glucose, fructose will not enter gluconeogenesis pathway and it will only result in pyruvate. On a calorie deficit, that pyruvate will be used up, else it will end up in the fatty acid synthesis.

http://www.medbio.info/Horn/Time%201-2/carbohydrate_metabolism%20March%202007a.htm

Stephen said...

I like the French attitude. Enjoy all kinds of real food but don't be a steam shovel Mike.

Matt said...

I also want to know your thoughts on what Bill Strahan and "Anon" note, that in fact it seems unlikely that one would underconsume when in a metabolic ward. When there is no "business to go about" then how are they not more sedentary and just plain bored, that they'll reach for the vending machine food.

mhb said...

The internet is littered with folks who got fatter eating the "Nourishing Traditions" way.
Yeah, no wonder. It's neither low fat nor low carb.

john said...

mhb,

Cultures have success with diets that are more balanced, being neither low fat nor low carb.

Duke of Earls said...

I don't even worry about macronutrient ratios. I just eat what I know to be the healthiest foods - seafood (sardines for low mercury), fermented vegetables like kimchi, healthy-fat based plants like avocados, grass-fed meats when affordable, nuts, and lots of salad greens and spices. Ends up being low carb, but I really don't aim for that. I'm never hungry, and lost 80 pounds rapidly upon adoption of this protocol. For anyone who cares, I have been a binge eater since childhood and the hyperpalatable foods Stephan often brings up are the main culprit. Even now, though, I cannot enjoy something as seemingly benign as fruit without having binge cravings later in the day.

Granted that's anecdotal, but it's what I trust above all else at this point. I know that sugary carbs set me off (even fructose) for overeating however I recognize I'm not qualified to say the carbs themselves are the only reason.

SamAbroad said...

The low-fat and low-carb zealots have ruined the comments of this blog for me. There used to be great discussions here that we all learned a little more from.

Please take the crusades elsewhere please.

Greensmu said...

@Gallier

So your point is that people who are overweight synthesize more fat (from carbs obviously) and those who are lean have more dietary fat in their adipose tissue?

But that is still just a correlation with carbohydrate.

Is there any evidence showing carbs as the causal factor? The different adipose tissue fatty acids can't tell us how many calories people are eating-just what kinds. Why can't I just claim that it's an increase in consumtion of yummy convenient carbs that causes the increased fat mass? The evidence can be explained in different ways so it's not very convincing.

allison said...

We are clearly hard-wired to prefer fat in our diets. It may be as simple as Mark Cohen's observation that large fatty animals provided the greatest bang for the metabolic buck. In the more extreme latitudes, fat would have meant the difference between starvation and survival during the cold months. (And in Neolithic times, agriculture was hard, back breaking work.)

I'm not surprised that the test subjects opted for sweetened fat. Think about being offered a choice between Skittles and fresh butter cream frosting. The combination of sugar and fat is completely unnatural, except for some tropical fruits and human milk, and may short circuit our metabolic wiring when abundant. Think about how easy it is to over feed on milk chocolate or ice cream.

Where would a H-G living among the retreating ice sheets find that combination? Have you ever seen anyone overeat liver or tongue?

gallier2 said...

@Greensmu

No, my point is the refutation of Carbsane's assertion that DNLG doesn't exist or is negligible. It's also a refutation that people's stored fat comes only from the fat eaten. If the fat stored in obese people had the same lipid profile as the one of the none obese, one could conclude that. Where does the proportionaly more long chain fatty acid in obese come from? DNLG is the likely source, because I don't think that they consume more beef tallow.
My second point, was that fructose is almost always stored as fat in the presence of a lot of glucose when hepatic glycogen store are full.
There was not more and not less in my comment and I certainly don't have an all compassing theory of obesity to present.

Greensmu said...

@Gallier

Thanks for clarifying. I just figured out what DNLG means and that your post wasn't just a random proclamation but a response to carbsane. It now makes much more sense.

I'm new to this so I am mostly criticizing others ideas and seeing if I can poke holes in them or get a more detailed explanation.

Galina L. said...

I grew up in the fast-food-free society and I saw that the main difference between cafeteria food impact and home-cooked food impact was in the delay and smaller magnitude of still the same health problems of civilization. It was not exactly up to Weston Price Foundation , but quite healthy - a lot of fish as a protein source because meat coasted 4 times more, sauerkraut everyday at winter, significant proportion of consumed bread was a sourdough rye kind.There were no fat children and young people, but significant portion of middle-aged were quite plump and all old folks looked skinny-fat or just fat with high blood pressure and heart diseases. Cafeteria food is so unhealthy that people here almost worship home-cooked meal preparation.
By the way, I already posted in one of previous Steven's blogs that I personally knew several people in Russia who grew fat by drinking a lot of sweet tee with bread (fat is not an ingredient) and fruit preserves(homemade, of course). It is still very popular way of eating for low-income people in Russia. Prices for most of food items are the same as in USA, but loaf of bread costs approximately 50 cents.

Galina L. said...

I grew up in the fast-food-free society and I saw that the main difference between cafeteria food impact and home-cooked food impact was in the delay and smaller magnitude of still the same health problems of civilization. It was not exactly up to Weston Price Foundation , but quite healthy - a lot of fish as a protein source because meat coasted 4 times more, sauerkraut everyday at winter, significant proportion of consumed bread was a sourdough rye kind.There were no fat children and young people, but significant portion of middle-aged were quite plump and all old folks looked skinny-fat or just fat with high blood pressure and heart diseases. Cafeteria food is so unhealthy that people here almost worship home-cooked meal preparation.
By the way, I already posted in one of previous Steven's blogs that I personally knew several people in Russia who grew fat by drinking a lot of sweet tee with bread (fat is not an ingredient) and fruit preserves(homemade, of course). It is still very popular way of eating for low-income people in Russia. Prices for most of food items are the same as in USA, but loaf of bread costs approximately 50 cents.

Henrik said...

Heres a video explaining HOW and WHY.:

http://www.dietdoctor.com/

Gordon Rouse said...

While these studies shed some light on what foods induce us to overeat, I would say it fails to really shed much light on what makes one person naturally fatter than another.

These experiments, like most observational studies being used to justify dieting and "healthy" eating, lack an important dimension - time.

Would the cafeteria diet alone be able to make a person of "normal" weight become obese? Maybe short-term, but long term?

It would be unethical to run this experiment long enough to answer this question, however I think we have enough other evidence that the answer is 'no'.

Dr Ethan Sims' experiment with the skinny prisoners has some similarities and differences, however I suspect it predicts the long-term outcome of a cafeteria diet. The participants, after initial weight-gain eventually peak in weight, become less interested in food and adapt to their regime. Eventually over the course of months to years (depending on different genetics) all of them will return to their initial starting weight.

If a cafeteria diet could explain obesity, then I would have to conclude that fat people eat more 'cafeteria'-like food, and that fat people could easily lose weight by changing to a less palatable diet.
I think it is obvious that the above two predictions are not true.

morten_g said...

Sounds like the experiment was fucking boring to the volunteers. I definitely crave junk more when I am bored than when I am intellectually stimulated.

Jens said...

Overeating carbs does not make the body put on as much fat as when overeating carbs.

I hope no one doubts this because it's basic science. Think glycogen and DNL for carbs which is very, very low.

So I'm not completetly sure what K.Harris is saying when he says that carbs and fat both make you fat in excess. Yeah well duh, of course they do but there's a HUGE difference between overeating the two and he should know it if he's a doc.

Asim said...

As I've said before, much of the weight in the fat tissue for an obese person is not from the fat cells, but actual macrophages. If your not targetting inflammation in your attempts to reduce obseity and all it's resultant metabolic disorders, you'll be pretty unsuccessful...

http://www.cumc.columbia.edu/publications/in-vivo/Vol3_Iss01_jan26_04/index.html

Asim said...

When "energy excess" happens, mitochondrial dysfunction happens. Superoxide is released to stop the overflow of excess energy into the cell. Too much accumulation leads to ROS, which damages the cell. Macrophages are probably released into the tissue to search out all the damage. This causes further damage, because all these macrophages have now accumulated trying to clean out the mess that had already started.

Asim said...

Some scientists also speculate that fat cells that get too much energy just die and the macrophages have to come and clean them up.

This cumulative effect is what leads to all these metabolic disorders we see. It seems to be just the cumulative effect of too much eating leading to energy excess, which has been compounded more greatly by processed foods, as well as inflammation.

Asim said...

Part of the problem I am seeing as an outsider when speaking about traditional diet versus Western diet, is that the latter has already been a victim of energy excess, which seems to be the trigger behind the whole problem. Whether it started in child-hood, teenage years or beyond, damage ahs already been done as a result of the inflammatory processes.

A change in the diet that does not take into account this inflammatory process, which includes GUT FLORA, will not be that successful.

Health should be seen in this context, not 'big' versus 'little'.

Evelyn aka CarbSane said...

@Gallier: I had started a response the other day and it got too long, so I turned it into a blog post: The Dietary Source of Body Fat. Please be careful in characterizing what others have said ... I did not say it doesn't exist, I said it is not significant. Energy balance also determines if lipids formed by DNL are accumulated in fat tissue or oxidized later. In the Triglyceride series I linked to in the above post, they determined that increased VLDL triglycerides on high carb were due mostly to slower clearance -- perhaps to keep more circulating lipids available for lipolysis/burning.

I think it is really sad that in this day and age we're still having this discussion of where most of our body fat comes from.

Evelyn aka CarbSane said...

@Jens: I don't think Kurt meant the uber-extremes of overfeeding studies. I don't have the link right now, but if memory serves there was a study where they overfed (like by thousands of calories/day) people with either added fat or added carb. The very high fat group gained more weight (something in the mid 90's percent of predicted by calories) than the high carb group (something in the mid 80's percent). Which makes sense b/c of the energy cost, as you mention, of DNL. Also carb is more thermogenic to begin with and to some degree stimulates its own oxidation.

But not to speak for Kurt, on the SAD, we're talking "extremes" perhaps of 35-to-45% fat, 40-50% carb that seems to comprise the diet of most obese. In those middle ranges, we burn the carb, store the fat for the most part.

Carnivore said...

I went throught that study and the very high fat diet was basically a high carb diet with lots of added fat, i.e. SAD. It was nowhere near anything resembling low carb. Also, the weight gain was higher initially in the higher fat diet but actually evened out over the course of the study, so that the higher carb group had gained slightly more weight in the end, even if it wasn't statistically significant.

I've said it before and I'll say it again: keeping carbs low, one can eat well over maintenance calories through fat and protein and not gain bodyfat. I don't know the science behind it, but I've been doing it for a long time and have abs to show for it. Conversely, when I was eating high carb and low fat, I easily gained bodyfat eating 400-500 calories less than what I consume now.

I look forward to studies which explore the effects of overfeeding with high carb and high fat diets. And by high fat, I don't mean the SAD. An actual low carb, high fat diet.

Roberto said...

Evelyn,

"But not to speak for Kurt, on the SAD, we're talking "extremes" perhaps of 35-to-45% fat, 40-50% carb that seems to comprise the diet of most obese. In those middle ranges, we burn the carb, store the fat for the most part."

Are you saying that such macronutrient ratios lead to fat storage after a meal, short-term. Or are you suggesting that it leads to obesity. I seriously doubt the latter to be the case.

Evelyn aka CarbSane said...

Hi Roberto,

No, I'm not saying the macro combo leads to obesity -- it's the excess calories. But most of the obese tend to eat somewhere in those ranges -- usually upwards of 35% calories in fat, and surprisingly, often under 50% carbs. In the ranges I stated, and perhaps up to 65% carb - higher still if you're not horribly in positive energy balance, the "excess" will be the fat calories. Mostly because of limited storage, our metabolisms are geared to burn the carbs first and store the fat in fat tissue until its needed.

If you're not overeating, it gets burned overnight. This is the whole nonsense of the insulin hypothesis because insulin will only be locking away fat if you've eaten too many total calories so you basically burn mostly carbs for longer periods. Hope that makes sense.

My point on the %'s was simply that you do see a difference with true extremes, but not really across a broad range in between.

Evelyn aka CarbSane said...

@Carnivore, if memory serves the fat overfeeding was with like 150g carbs. If you think it would have been different replacing that with roughly 67g fat you're kidding yourself.

Jared M Johnson said...

I'm kind of annoyed that the word 'palatable' seems to be thrown around without any real meaning or definition. It always seems like someone trying really hard to connect things that aren't necessarily connected.

I would love another, more precise term, that doesn't seem to change depending on the context of what you're trying to show.

Really, the whole palatability idea is about moving from more precision to less precision. Instead of being more precise, you've adopted this word that could mean incredibly many different things. It all sees pretty damn lazy to me. Is it the sugar? Is it the gliaden? Is it the fat? Is it a particular combination?

Is there a definition out there that isn't so damn slippery?

Kurt G. Harris MD said...

@Jens

"So I'm not completetly sure what K.Harris is saying when he says that carbs and fat both make you fat in excess." "

I did not say both do, I said both can. It makes no practical difference which you are eating more of if you are in substantial caloric excess.

The point is if you are hypercaloric. Do you disagree with this?

"Yeah well duh, of course they do"

Well it may be obvious to you but read some of the other comments here. Plenty of people think low carb is magic and won't make you fat, and plenty think you can't get fat on a practically achievable low fat diet. I've seen both happen plenty of times.

"But there's a HUGE difference between overeating the two and he should know it if he's a doc."

In the real world, few people are eating at either the extreme of VLC or the uber low fat diets that are nearly impossible to tolerate, much less with real food products. Very low fat diets with any natural animal products at all are very hard to achieve unless fish is the only animal eaten. (like the Kitavans).

A person eating 25% carb and 55% fat and another eating 55% carbs and 25% fat can both gain fat if they overeat. This is primarily determined by food quality, and efficiency of fat storage or DNL has little effect at these levels.

So outside of experimental dietary macro ratios that are very difficult to achieve with real food that also meets your other nutritional needs, there is most certainly not a HUGE difference.

Evelyn is correct (and Stephan agrees) that it is "easier" metabolically to convert fat to fat than carbs to fat. I agree. Yes, "Duh"...

But the practical significance of this relative to the combinations of ingredients that create hyperpalatable food, and the effect of toxins that disturb regulation of appetite is limited.

The body has a regulatory mechanism for fat storage that involves leptin, the hypothalamus, etc. Leptin levels depend on fat MASS and are not dependent on whether the fat came from carbs inefficiently or fat efficiently. The process is not passive.

That is why I don't buy that the reason the Kitavins are not obese is "because they eat high carb". It is because the don't overeat, which is in turn because they eat real food that does not dysregulate their appetite.

Neither "carbs" not "fat" overdetermine any measure of health. These categories are too broad to have explanatory power and the thesis that either macronutrient ratio explains disease or obesity simply fails when looking at all the evidence.

Neither fat not carbs are the black monolith of obesity or health.

Kurt G. Harris MD said...

Evelyn said:

"My point on the %'s was simply that you do see a difference with true extremes, but not really across a broad range in between."

What she said....

Kurt G. Harris MD said...

Evelyn said:

"My point on the %'s was simply that you do see a difference with true extremes, but not really across a broad range in between."

What she said....

Kurt G. Harris MD said...

Evelyn said:

"I think it is really sad that in this day and age we're still having this discussion of where most of our body fat comes from."

Ha Ha

This whole discussion about whether fat "comes from" either the carbs or fat that we eat is like asking whether the electron that comes out at the end of the wire is the same one that originated at the power plant : )

Or whether the money you blew on a lottery ticket came from your WIC payment or your unemployment check....

Caloric excess leads to fat storage.

The fuel molecules you eat don't come with reserved tickets to particular seats in your metabolism.

Asim said...

http://home.trainingpeaks.com/articles/nutrition/a-calorie-is-not-a-calorie.aspx

Mozart Reina said...

Perhaps it's all Leptin? This post by neurosurgeon Jack Kruse is quite interesting. It also supports the idea that it's all happening in the brain.

Brain -> hormone regulation -> energy regulation

http://jackkruse.com/why-is-oprah-still-obese-leptin-part-3/

I also don't understand why people think it matters if carbs or fat get stored as body fat or not. Unless you're eating every 2 hours, adipocytes will release FFA to meet energy needs, so why does it matter if cars or fat get stored? They just get re-released anyway.

Evelyn aka CarbSane said...

@Mozart: I also don't understand why people think it matters if carbs or fat get stored as body fat or not. Unless you're eating every 2 hours, adipocytes will release FFA to meet energy needs, so why does it matter if cars or fat get stored? They just get re-released anyway.

Yep ... energy needs and expenditure dictate net storage.

Leptin regulates fat mass through "external" means: increase lipid oxidation (and I've just discovered some research indicating ASP may also)and suppress appetite.

Evelyn aka CarbSane said...
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Asim said...
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Helen said...
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Asim said...
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Asim said...

"When a diet of mixed macronutrient composition is eaten to excess, the carbohydrate is preferentially burned off, while the fat is mostly shunted into fat tissue. This makes sense, because why would the body go through the inefficient process of converting carbohydrate to fat for storage when it can just shunt dietary fat directly into fat tissue? This does not imply that dietary fat is fattening under conditions of energy balance."

Just a few question:

1. How was this conclusion derived?
2. If your in energy excess, wouldn't BOTH "carbs" and fats be stored by the fat cells, because the energy needs are already being met?

Helen said...

@ Dr. Harris,

Although WIC can't be converted to lottery tickets directly, so not an exact analogy.

This is what WIC does: http://www.fns.usda.gov/wic/aboutwic/wicataglance.htm.

This is what you can use WIC coupons for. Perhaps a notch or two better than the cafeteria diet:
http://www.mass.gov/?pageID=eohhs2terminal&L=5&L0=Home&L1=Consumer&L2=Basic+Needs&L3=Food+%26+Nutrition&L4=Women%2C+Infants+and+Children+%28WIC%29+Nutrition+Program&sid=Eeohhs2&b=terminalcontent&f=dph_wic_c_list_food&csid=Eeohhs2

Asim said...
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Asim said...

"Carnivore, if memory serves the fat overfeeding was with like 150g carbs. If you think it would have been different replacing that with roughly 67g fat you're kidding yourself."

Wouldn't the former cause a pretty rapid spike in blood sugar, leading to a rapid rising of insulin?

Kurt G. Harris MD said...

@Helen

You are correct but that reinforces my analogy.

My point was the ultimate fungibility of units of measure, in this case energy balance units.

Although a WIC coupon cannot be used directly to buy beer and cigarettes, there is no ultimate accounting or balance sheet difference between using a WIC coupon to buy smokes and using WIC coupons for the allowed food and thereby freeing up cash to buy things you can't buy with WIC.

So WIC is like carbohydrate, which is preferentially burned over being converted to fat, but contributes to fat storage on an "energy accounting" basis.

Like when you lend a relative money and they buy some useless gimrack. And you say "Hey' I didn't lend you money to buy THAT..." And they retort that they used DIFFERENT money to buy the item, not what you lent them...

So the WIC and cash analogy is actually a very good metaphor for the fate of metabolites.

It is true that most fat stored comes from dietary fat, but carbs can contribute to fat storage because they are being burned in preference to fatty acids, thereby resulting in more fat storage if the carbs were what put you into caloric excess...

The point being, glucose and fatty acids are not literally fungible - the same commodity, but on an energy balance sheet basis they are.

You could also look at Dollars and Euros when the exchange rate is relatively stable. Same principle..

Kurt G. Harris MD said...

@Asim


1. How was this conclusion derived?

Basic biochemistry. See Stryer or Leninger or Guyton or Frayn's' metabolic regulation

2. If your in energy excess, wouldn't BOTH "carbs" and fats be stored by the fat cells, because the energy needs are already being met?

No, the carbs are preferentially burned and if there is excess energy beyond metabolic and structural needs fatty acids are stored as fat on a net basis.

See my WIC and cash analogy. Burning one currency makes the other more available for storage if in excess.

Asim said...

@Kurt

"No, the carbs are preferentially burned and if there is excess energy beyond metabolic and structural needs fatty acids are stored as fat on a net basis."

I'm trying to wrap my head around this and the difficult part I'm havingis:

But again, in this case your not using the carbs so to speak for energy, because your in energy excess. Where do the 'carbs' go? Do they just keep circulating in the bloodstream until they are eventually used up, while fat is selectively being pushed into the cells to to be stored?

Carnivore said...

I went through it again and found no statement about the amount of carbohydrate in the diet. They simply say that the subjects were fed 150% of their maintenance calories with the extra 50% coming from fat. A look at this sample menu taken from the appendix shows that the diet was anything but low in carbohydrates:

Fat overfeeding: diet example
Breakfast Cream of wheat, dry weight 35
Whipping cream 202
White sugar 11
Butter 9
Banana, peeled 70
Orange juice 120
Lunch Plain bagel 80
Roast turkey breast, no skin 50
Cheddar cheese 21
Lettuce 25
Mayonnaise 17
Chocolate milk (1% fat) 200
Whipping cream 120
Vanilla ice cream (16% fat) 140
Chocolate syrup 34
Snack Peanut butter cup 51
Dinner Round steak (lean, broiled) 81
Boiled potatoes 130
Whipping cream 30
White bread 25
Broccoli, boiled 90
Butter 30
Snack Saltine crackers 11
Cheddar cheese 20
Example of food module (only offered during baseline diet)2
Banana, peeled 65
Peanut butter 13
Milk (2% fat) 120

I just copy-pasted it here and it's not very readable so I suggest visiting the link:

http://www.ajcn.org/content/62/1/19.full.pdf+html

To be honest, I think anyone would struggle to eat 150% of their maintenance calories on a true high fat-low carb diet because of the high satiety factor, which is why the diets are designed to be fairly high in carbohydrates.

Kurt G. Harris MD said...

@Asim

"Where do the 'carbs' go? Do they just keep circulating in the bloodstream"

No, they are buffered by being stored as glycogen, the storage form of carbohydrate.

rick said...

CarbSane, KurtHarris: If it's all about calories why don't we strap two identical twins to a bed for 3 months and feed one 2000 calories protein/day and the other 2000 calories of alcohol/day. What will be the body composition of each at the end of this experiment?

Here's what an alcoholic looks like:
http://www.youtube.com/watch?v=gr0hrM_Yqxc&feature=BFa&list=PLA1F713A28875E639&lf=results_video#t=7m20s keep in mind.

Also Carbsane, what do you attribute your 'softer' look in your profile to. Hormones, calories, something else? And what causes this softer look as we get older compared to say a younger picture of yourself.

bentleyj74 said...

The alcoholic looks better than the dead guy Rick.

Travis Culp said...

I'm continually amazed by the refusal by so many in the ancestral diet sphere to accept that dietary long-chain fatty acids not only can, but very likely are, stored in adipocytes. Where do you think the chylomicrons go? Outer space?

john said...

Travis,

Who thinks this?...only devoted Taubesians, and there aren't that many.

Carnivore,

Thank God someone else sees the weakness in this and other similar studies. Also, I think I eat only about 3 or 4 of the foods on that list.

berto said...

Dr. Harris,

""Where do the 'carbs' go? Do they just keep circulating in the bloodstream"

No, they are buffered by being stored as glycogen, the storage form of carbohydrate."

Same question to you, but let's assume glycogen levels are at maximum. Where does the glucose go now?

-Al

Kurt G. Harris MD said...

@Berto


"let's assume glycogen levels are at maximum."

When you eat a meal with starch in it, the glucose is absorbed into the bloodstream. Insulin released by the pancreas in response to the NORMAL rise in blood glucose will tell cells to take in more glucose and will decrease the release of fatty acids in order to favor burning glucose over fatty acids.

The insulin also stops the liver from doing its normal thing of continuously dismantling glycogen into units of glucose and releasing them into the blood. It also tells the liver to take up extra glucose and polymerize it into more glycogen. This is how in normal people the liver buffers dietary glucose - this is the main thing that fails in type II diabetes.

Glycogen is constantly being depleted any time you are not eating glucose and adding it to your blood.

So in the premise of your question is if glycogen stores ( the liver esp) are ever 100% topped off.

It is kind of like asking why the gas does not spill when you fill your tank in your car. It is because you are constantly depleting it all times, and when you eat you are topping off. So your glycogen stores are never completely saturated at the time you eat carbs, because you have burning them continuously until the time you eat.

Now, if you eat to caloric excess on high carb low fat and the fat is all stored and there are still glucose molecules in excess of glycogen replenishment needs, then that is where there will be some DNL and the glucose will be turned into fat.

Make sense?

(GLycogen is found in both muscle and liver but the liver is the main "gas tank" and storage tank of glucose on a moment to moment basis for the brains needs.)

Kurt G. Harris MD said...

@RIck

"CarbSane, KurtHarris: If it's all about calories why don't we strap two identical twins to a bed for 3 months and feed one 2000 calories protein/day and the other 2000 calories of alcohol/day. What will be the body composition of each at the end of this experiment?:

Get serious. That's a ridiculous straw man, already self-immolating as we speak.

Alcohol?

How about using wood chips or dried animal dung? They have caloric value if you burn them, too, but none of these items is food, is it?

The thing that is "all about calories" is that when humans eat a diet of actual food that meets their protein and micronutrient needs then whether they gain fat is determined by caloric excess.

This does not mean that food quality and food reward and toxins and other things don't affect whether we overeat and how much.

I believe they do, but if eating certain things makes us fat it is mediated VIA the caloric excess.

Not, via eat glucose - insulin rises - fat locked into fat cells that can't escape, for instance.

If you had ever read any of my blog, you would know I hardly think human health is "all about calories".

Travis Culp said...

Glycogen doesn't have a fixed threshold as most imagine either. Rather, it can become super-saturated beyond what the body comfortably prefers and the result is that the muscles/liver run off of the glucose at an accelerated rate for an extended period of time until the threshold is crossed. You REALLY have to overeat starch in order to turn glucose into lipids.

It's the same ultimate result whether glucose intake causes a mitochondrial substrate shift vs. if it were immediately converted into fat (which it is not). However, we may as well be aware of the mechanisms instead of being willfully ignorant of the biochemistry.

All of these things make sense since evolution favors the most efficient routes. If we couldn't store dietary lipids as body fat due to some horrible mutation along the way, we would have died out a long time ago.

Carnivore said...

Quite frankly, I don't see the point of this discussion about whether it's dietary fat that gets stored as bodyfat or carbohydrates, when a person is eating a crap diet high in both carbs and fat. As far as I'm concerned, it's the carbs that allow such significant overeating in the first place and it's because the body has to normalize blood sugar first that the dietary fat gets stored as bodyfat. Why eat so many carbs in the first place? Carbs are a metabolic bully, they fight to be burned first and not burning them can lead to dangerous consequences. The effect of fat in the diet in the presence of plentiful carbs is completely different from it's effect when carbs are limited.

The question that should be asked is if it really is possible to become obese without eating a significant amount of carbs. I have yet to see anyone who points out the silliness in Taubes' theory (however wrong it may be)actually show some evidence that eating fat and protein ad libitum can make a person fat while restricting carbs. Every so called high-fat diet which achieves this result is also fairly high in carbs. Using a percentage like 30% doesn't cut it. Suppose I eat 30% out of my daily 3400 calories as carbs; that equates to 255 grams of carbs. Is that low carb? No. Will I get fat eating this way? Hell yes. I've tried it with less fat and less calories and found out that I do indeed gain bodyfat.

I came across this study and found it quite interesting:

http://www.ncbi.nlm.nih.gov/pubmed/3781723

Basically, the purpose of the study was to study the thermogenic response to fat overfeeding in lean and obese subjects. The last line in the abstract:

"These results suggest that there is a flexibility in the normal thermogenic response to fat in lean subjects but a reduced response in those with familial obesity."

Keep in mind that none of the subjects were fed a low carb diet.

Myself and several others have reported eating in "caloric excess" consistently and not putting on fat while low carbing. I do not believe energy is somehow destroyed, rather the body is flexible in increasing calorie expenditure when the diet is low in carbs. I do not know the mechanism for this, but I believe it's something that ought to be studied.

rick said...

Alcohol?

How about using wood chips or dried animal dung? They have caloric value if you burn them, too, but none of these items is food, is it?"

What about sucking through a tube in 1965. Is that considered food? What about rice krispies?


"The thing that is "all about calories" is that when humans eat a diet of actual food that meets their protein and micronutrient needs then whether they gain fat is determined by caloric excess."

Then make the experiment 100g protein each and a multivitamin full of micronutrients and the rest of the 1,600 calories as alcohol (at 7KCal/g) and the other protein -- or instead of alcohol, use fructose, or even 'safe starch' rice krispies. Will fat-mass body composition be the same on all 4 identical twins now. Look at what the hypoglycemia in that UC Berkeley: Alcohol video linked earlier did to the person's legs and arms.

if eating certain things makes us fat it is mediated VIA the caloric excess.

Not, via eat glucose - insulin rises - fat locked into fat cells that can't escape, for instance.

If you had ever read any of my blog, you would know I hardly think human health is "all about calories".


What do you make of the Randle cycle mentioned in Taubes GCBC. Or what about this statement from UC Berkeley Nutrition lectures: "Insulin levels decrease: stimulates gluconeogensis, protein breakdown, lipolysis: lipid breakdown

Or these other catabolic/anabolic hormones/enzymes cited by Taubes and Robb Wolf: glucagon, cortisol , LPL.... do any of these have a physiological role in fat gain/loss?

Carnivore said...

Reading the above post leads me to ask: what determines caloric excess? What if the macronutrient composition of the diet itself causes the calorie expenditure to vary? It's an implicit assumption in the back and forth here that calorie expenditure does not vary with diet composition. I don't think we can be so sure about this, especially when talking about a low carb diet.

Evelyn aka CarbSane said...

Thanks Kurt for giving it a try there with Rick. Saved me wasting time.

@Carnivore: Apologies, I was thinking about the wrong study.

I think this is the one:
http://www.ajcn.org/content/62/1/19.full.pdf

Still, the study involved monitoring usual intake and then adding 50% extra calories of either all fat or all carb.

The fuel usage plots on p. 23 of the PDF are interesting.

Evelyn aka CarbSane said...

@carnivore:

The fat overfeeding study I'm thinking of included up to 600g fat keeping carb at 150g.

As to getting fat keeping carbs low? Jimmy Moore comes to mind.

It would be interesting to find the full text of your study. 1000 cal/day overfeeding leads to about 7% difference in energy expenditure changes in lean v. obese. This doesn't really tell us what caused that increase in EE.

François Létourneau said...
This comment has been removed by the author.
Frank said...

Here is a good review to get started regarding storage of carbs and fat

Use and storage of carbohydrate and fat.

http://www.ajcn.org/content/61/4/952S.long

It's kind of hard to figure how Taubes could come along with the idea that a lot of % of carbs are turned into fat when, as Kurt said, well recognized basic biochemistry tells us otherwise.

gallier2 said...

People, you should really follow up Carbsane's link where she addressed the issue of DNLG. The last study she presented there is excellent and should be read absolutely.
The study showed without a doubt that normal weight and healthy people on SAD diet comprising around 100 g/day of fat, do generate around 20% of there deposited fat from DNLG. That was the measurment for the dynamic part of the process. FFA flow continuously from and to the adipocyte.
The total composition of their subcuteanous fat is around 10% coming from the traced DNLG.

The study had some technical restrictions which suggest that the number presented are on the low side of things, as the DNLG from fructose was not measured and visceral fat was not probed. Furthermore, I'm persuaded (yes it's an unbacked opinion) that in the overeating (whatever the reason) obese people the proportion of DNLG will grow.
The epidemy of NAFL in the western world being another clue that DNLG might not be as "negligible" as people try to make it.

To be clear and because the comments here are full of mischaracterizations of the arguments of others (yes Travis, I mean you among others), there is noone denying that dietary fat is stored in adipose tissu, it would be dumb if it wasn't. It is also logical that the body will try to get rid of the glucose as fast as possible (as it is quite toxic) but as it is rather precious, it will avoid to dump it in the gutter. Three methods for that:
- burn up preferentially => slow down fat metabolism
- store as glycogen => costs only 7.3% of its energy but capacity limited to 500g
- convert to fat and store => costs 25% of its energy, but still better than dumping which would cost 100%

TLDR;
on weight stable healthy people DNLG is only a minor contributor to total fat mass.
on overweight obese people probably not.

Evelyn aka CarbSane said...

@Gallier, they measured palmitate for DNL which is the byproduct from whatever substrate feeds into the DNL pathway.

For the obese DNL would lead to a lower percentage of fat not a higher one.

Taubes has dropped this schtick. Time for others to as well.

@Carnivore: It's an implicit assumption in the back and forth here that calorie expenditure does not vary with diet composition. I don't think we can be so sure about this, especially when talking about a low carb diet.

This strawman again? Nobody denies thermogenesis. But if anything that favors carbs over fat particularly when we're talking about excesses. Carbs must be converted to fat to be stored = energy expended, while fat requires little energy to be stored. I've yet to see any study demonstrate a change in BMR or TDEE on low carb vs. high carb.

john said...

Carbsane,

If we're assuming some people can't handle a "balanced" [fat, carbs] approach, who cares where the body fat comes from in that context? Those people apparently must choose between fat and carb restriction anyway, and those trials have been done. You're making a strawman argument as well: nobody makes the blanket statement that dietary fat cannot become bodyfat. People simply claim they can get away with more calories restricting carbs than restricting fat (and better appetite control). How do the study comparisons of adding carbs vs fat to a balanced diet have anything to do with what many pro-low-carbers claim? You do the same thing with your thermogenesis argument: You can't take a balanced diet, add carbs or fat, then conclude fat restriction is superior because carbs increased heat more in that context. Ketogenic animals almost always have to eat significantly more calories than lowfat controls to maintain weight.

Kurt G. Harris MD said...

@Rick

"What about sucking through a tube in 1965."

Who mentioned that? I didn't. That would have to do with FR, no one is proposing the calories are burned differently based on the mode of delivery, unless you are?


Is that considered food? What about rice krispies?

What is your question or assertion? If you overeat rice krispies by 500 kcal that is the same as overeating potatoes whether one is more food than the other or not. The food issue affects the likelhood of spontaneous overeating, not the fate of excess calories.



"Then make the experiment 100g protein each and a multivitamin full of micronutrients and the rest of the 1,600 calories as alcohol (at 7KCal/g) and the other protein -- or instead of alcohol, use fructose, or even 'safe starch' rice krispies. Will fat-mass body composition be the same on all 4 identical twins now. Look at what the hypoglycemia in that UC Berkeley: Alcohol video linked earlier did to the person's legs and arms."

One more time: ALCOHOL IS A POISON_ A HEPATOXIN IT IS NOT FOOD EVEN IF YOU CAN BURN IT IN REASONABLE AMOUNTS IT TELLS US NOTHING TO EXPERIMENT WITH A TOXIN, GET IT?


"What do you make of the Randle cycle mentioned in Taubes GCBC. Or what about this statement from UC Berkeley Nutrition lectures: "Insulin levels decrease: stimulates gluconeogensis, protein breakdown, lipolysis: lipid breakdown"

What do you mean what do I make of it? The Randle cycle is old hat, so what? It does not have anything to do with what happens to caloric excess, period. It is how the body cycles between internal fuel sources.

"Or these other catabolic/anabolic hormones/enzymes cited by Taubes and Robb Wolf: glucagon, cortisol , LPL.... do any of these have a physiological role in fat gain/loss?"

Of course they do, why wouldn't they? But none of them mitigate a caloric excess in a normal physiologic state.

Why don'y you listen to my 1:45 interview with Robb Wolf I did 2 weeks ago and then you can do a little more reading on metabolism before going on the warpath?

I've been reading about this stuff for over 4 years solid and Stephan and Evelyn seem to read a little bit too. None of us know everything bur we have all heard of the Randall cycle.

Kurt G. Harris MD said...

@Travis

Yes the glycogen gas tank is "stretchy" and has variable capacitance...

Travis Culp said...

"To be clear and because the comments here are full of mischaracterizations of the arguments of others (yes Travis, I mean you among others), there is noone denying that dietary fat is stored in adipose tissu, it would be dumb if it wasn't."

Read the first response to this post.

I used to think that you could only get obese eating tons of fructose, but I'm now starting to think that you could do it with a total absence of fructose in the diet. Few obese Americans take this route, but it should still be possible. You would just need to have a high insulin:glucagon ratio due to the constant presence of carbohydrates in meals/snacks coupled with a fairly large amount of dietary fat (that is shuttled to adipocytes) and very little activity, most of which simply results in glucose oxidation in the muscle mitochondria. Lipids would only be oxidized in small amounts by cardiac muscle mitochondria for a few hours while you sleep and in your other muscles if you roll over etc. Do this for long enough and the fat would continually pack on.

Most of our hypothalamic compensatory mechanisms are intended to manage starvation, not the evolutionarily inappropriate state of excess.

john said...
This comment has been removed by the author.
Evelyn aka CarbSane said...

@Travis, I'd say it's more than possible. It's how I got fat as my demons aren't really sweets so I ate far more starch+fat than sugars. Give me fish and chips, ziti with meat sauce, pizza, chinese food, etc. every day and gaining weight is more than possible, it's inevitable! (Unless I were to count calories, but it would be hard to do so eating those foods regularly).

@john: Hormones can alter metabolic rate but the question is does dietary composition alter the hormones that do? I've yet to see a study where BMR was measured that showed any difference across a rather wide range of macro intake.

For the most part, overeat 500 cal and you store 1/7th pound. Your body may try to waste some of it, and leptin tries to help it waste a little more as stores build a bit but that is not due to the composition of the food. If anything, carbs have a very slight edge in this department.

Evelyn aka CarbSane said...

@john:

If we're assuming some people can't handle a "balanced" [fat, carbs] approach, who cares where the body fat comes from in that context? Those people apparently must choose between fat and carb restriction anyway, and those trials have been done.

Exceedingly few people cannot handle a balanced diet metabolically. By this I mean the problems with middle-of-the-road diets is that they are more difficult to control intake ad libitum -- so easier to gain weight on. But in caloric deficit it's a wash for the most part.

You're making a strawman argument as well: nobody makes the blanket statement that dietary fat cannot become bodyfat.

The very first response was "This post has good info, but suggesting the fat is stored as fat is absolutely wrong and is bad science." ... that's what got this discussion ball rolling.

People simply claim they can get away with more calories restricting carbs than restricting fat (and better appetite control). How do the study comparisons of adding carbs vs fat to a balanced diet have anything to do with what many pro-low-carbers claim?

Again, I was responding to the comments of others. But by the same token, low carbers frequently point to fat futile cycles and overfeeding studies to claim they lose more when in deficit. Which is, as you say, irrelevant. Still, Eades likes to claim that at least you won't gain weight on LC excesses (that's in his latest book and on his blog), so, again, these claims must be addressed.


You do the same thing with your thermogenesis argument: You can't take a balanced diet, add carbs or fat, then conclude fat restriction is superior because carbs increased heat more in that context.

But I didn't. I'm saying that hypercaloric diets that are higher in carbs vs. fats will result in slightly less weight gain.

Ketogenic animals almost always have to eat significantly more calories than lowfat controls to maintain weight.

Ketogenic animals also tend to have more body fat by percent. (See for example: here) Desired?

Kurt G. Harris MD said...

@John

"What?!?! You're basically implying that hormones/proteins/etc regulate only appetite, not metabolic rate and/or macronutrient fate. So a forcefeed experiment of coconut oil vs cake [added to normal diet] would show no difference? "

None of this you just wrote has anything to do with what I wrote or claimed. Perhaps you should re-read it.

But since you asked, one might gain more fat on the coconut for reasons discussed right here in this thread. It takes more energy to convert the starch and sugar in the cake to fat than if you overate coconut. But the same starch content from rice krispies or potatoes would make no difference, which is indeed what I just said. Why would it not be the same for these two sources?

I have no idea what you mean by "hormones/proteins/etc.... as that is hopelessly vague and nonspecific. When did anyone say that hormones and proteins (which ones of the thousands?) regulate ONLY appetite. That is absurd, obviously. Some hormones regulate appetite and fat mass (leptin) and some just toggle between fuel sources (insulin). Which hormones and proteins were you interested in discussing?

""Overeating" does not equal "excess calories," unless you're referring to only the step of fat accumulation; but if this is the case, you might as well tell people to eat fewer calories than burn to lose weight."

That is in fact the only reasonable definition of caloric excess, isn't it? A person eats more calories in a certain time period than they use or perhaps eats at an equilibrium level of caloric intake when they have excess fat. What else could possibly be meant by overeating?

WHY they do so is the interesting question. Taubes thinks that insulin locks fat into cells and makes you hungry. I think generally certain food toxins or unnatural FR cause dysregulation of the leptin/brain axis and cause the fat setpoint to rise, which in turn makes you want to eat more to either gain fat to the new setpoint or keep it there. I think food quality affects the leptin/brain axis and the hypothalamic setpoint and this in turn affects appetite/

rick said...

I was just trying to find a line where a Calorie is not a Calorie, and in this blogpost it seems like you're taking a shotgun approach and saying just eat real food in 'energy balance'... but there are experiments where people are eating macronutrients (not real food) out of a tube. Alcohol (a substance that provides energy) can make energy and fatty acids. And I wanted you to look at the alcoholic whose muscles wasted away from hypoglycemia in the video (these are energy Calories that affected body-composition catabolizing the man's muscle and increasing belly fat).

Do you agree that fructose molecules/Calories are not the same thing as glucose as Lustig famously emphasized in his lecture, or do you say a 'Calorie is just a Calorie' when it comes to fat accumulation/body-composition?
-
re: Randle cycle
I was talking about this excerpt from GCBC: The second mechanism that works to regulate the availability of fuel and to maintain blood sugar at a healthy level is
called the glucose/fatty-acid cycle, or the Randle cycle, after the British biochemist Sir Philip Randle. It works like
this: As blood-sugar levels decrease—after a meal has been digested—more fatty acids will be mobilized from the fat
cells, as we just discussed, raising the fatty-acid level in the bloodstream.

-
And I did listen to your Robbwolf podcast weeks ago (where do you think I knew about your newfound rice krispies habit) and you were talking about yourself as "too old" for arguments @1hr17m30s and you later went on @1hr32m talking about rewriting an "Archevore diet flow chart" and a how glad you and Richard Nikolei were that you guys never wrote a book because of Stephan's work.

And you even said @1hr35m that Stephan Guyenet was influenced to his higher carbohydrate diet conclusion based on where he's from and raised, and that you largely base your diet on animals because you were raised in a prairie area. And I actually did make a comment in that podcast and you replied, but I don't think you clicked the links (and I don't think you're clicking the links in my comments in this blogpost either).

john said...

Carbsane,

"Hormones can alter metabolic rate but the question is does dietary composition alter the hormones that do."

Well if they don't then the food reward hypothesis should also be thrown out the window (as I'm pretty sure there's some hormone/protein/chemical overlap there--metabolic rate & appetite), and the nutritionists have been right all along: we became very gluttonous very suddenly.

"Again, I was responding to the comments of others."

Okay, but I was generally talking about people who are more well-known and respected, not random commenters with blatantly absurd claims.

"...overeat 500 cal...carbs have a very slight edge in this department."

This is debatable, as there are studies that go both ways and with different base diets. See Jaminet's references in his thyroid series.

"Eades likes to claim that at least you won't gain weight on LC excesses"

This is a different than saying you can eat more calories on low carb! I don't care what Eades says; I care about making a logical argument. People claim they can eat more calories low carb; to counter that you have to show counter evidence. This is inconclusive.

"I'm saying that hypercaloric diets that are higher in carbs vs. fats will result in slightly less weight gain."

This statement is false (I'm not necessarily saying the converse is true). Maybe (just maybe) forcefeeding carbs over fat on a balanced diet causes less weight gain, but what if the dieters are eating ketogenic--does this still apply? I don't think the study exists, but I would guess no, as, like you mentioned earlier, balancing out carbs and fat tends to cause weight gain in those susceptible.

"Ketogenic animals also tend to have more body fat by percent"

I said "almost always" about ketogenic animals needing more calories, and I would say the same about having lower bodyfat. I've also seen opposite effects on behavior and cognition.

john said...
This comment has been removed by the author.
Beth@WeightMaven said...

Kurt wrote: "I think generally certain food toxins or unnatural FR cause dysregulation of the leptin/brain axis and cause the fat setpoint to rise, which in turn makes you want to eat more to either gain fat to the new setpoint or keep it there."

I have some semantic quibbles with the idea of a fat setpoint. My (completely unscientific) preference is to view this as something in our environment, perhaps food toxins, that is overriding healthy appetite regulation. I.e., if removing problematic foods causes weight loss, is that lowering the setpoint or restoring normal function? Tomato, tomahto?

BTW, this discussion brings to mind a whack paper that Peter@Hyperlipid reviewed quite a while back theorizing fat was essentially the body's attempt to protect itself.

If 10,000 years is insufficient time to adapt to grains, then 100 years is an eyeblink re adapting to perpetual caloric overload from nutrient-poor foods. Yes, brain/leptin are disrupted, but I also think downstream damage (especially wrt the liver) contributes as well.

Kurt G. Harris MD said...

@Beth

"I have some semantic quibbles with the idea of a fat setpoint. My (completely unscientific) preference is to view this as something in our environment, perhaps food toxins, that is overriding healthy appetite regulation."

But that is equivalent to what I said. Overriding healthy appetite regulation is precisely having the setpoint set higher and maintaining it there. What else would it mean?


"I.e., if removing problematic foods causes weight loss, is that lowering the setpoint or restoring normal function? Tomato, tomahto?"

Normal function is not having abnornally high fat mass with ffa spilling out and IR and all the rest...

Beth@WeightMaven said...

Kurt, wish I could articulate better my struggle with the "raised setpoint" metaphor (I did say it was a quibble ;). Anyways, no biggie.

BTW, I liked your comment on your blog about lipotoxicity and overnutrition. The focus on macronutrient ratios certainly seems to be distracting from the consideration/implications of routine overfeeding ... mostly of what Stephan calls "professionally designed industrial food."

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Carnivore said...

Carbsane, Jimmy Moore got to 410 pounds eating the SAD. He then lost over a hundred pounds low carbing and if he regained some of that weight whilst continuing to eat low carb, that does not equate to becoming fat on a low carb diet. Plus, he already had a 'damaged metabolism' so to speak when he regained some of the weight. I have yet to see an example of someone originally becoming fat while restricting carbs.

That study from 1995 is a poor one to look towards for comparing fat and carb overfeeding as it contains too many carbs in the baseline diet itself. I'd be more interested to see the study where they restricted carbs to 150g/day. It's at least moderately low carb, if nothing else.

Btw, the study I referenced was just to make the point that fat overfeeding elicits variable responses and it's more important to look at individual data rather than the mean. The study was again poorly designed if you look at it because the fat was overfed on top of the baseline diet which was high in carbs. Not much can be gleaned from it but it does show that obese and lean people have different adaptive thermogenic responses to fat overfeeding and that EE can in fact increase to compensate for increased fat intake.

When you say this:

"This strawman again? Nobody denies thermogenesis. But if anything that favors carbs over fat particularly when we're talking about excesses. Carbs must be converted to fat to be stored = energy expended, while fat requires little energy to be stored. I've yet to see any study demonstrate a change in BMR or TDEE on low carb vs. high carb."

You are basing your opinion on what is known. I am saying there is a mechanism (unknown?) whereby fat overfeeding on a low carb diet increases EE such that weight/fat gain becomes virtually impossible. What this mechanism is, I don't know. I personally have experienced this as have many others; eating ridiculous amounts of calories and not putting on an ounce of fat as long as carbs are restricted. If you haven't seen such a study, it's probably because it hasn't been done yet. That does not, however, make my own experience or that of many others any less real.

What I'm hoping for is such a study which compares overfeeding of carbs and fat on true high carb and low carb diets, respectively. An adequate amount of protein can be selected and made constant across both diets. The subjects can be selected to be a mix of obese and lean people and the study should go on for a month at least. The results should check for changes in bodyfat and EE among other things to see how they compare for both the diets.

Evelyn aka CarbSane said...

@john:

This is the comment section on a post on Stephan's blog. So I don't get this:

Me: "Again, I was responding to the comments of others."

Okay, but I was generally talking about people who are more well-known and respected, not random commenters with blatantly absurd claims.


Comments on a blog are intended for discussing the post and often branch out into conversations between commenters. I guess I don't get saying "nobody says that" when that is a topic brought up in a comment here. But then

Me: "Eades likes to claim that at least you won't gain weight on LC excesses"

This is a different than saying you can eat more calories on low carb! I don't care what Eades says; I care about making a logical argument. People claim they can eat more calories low carb; to counter that you have to show counter evidence. This is inconclusive.


So now you don't care what a supposedly more well known and respected person says, you want me to provide evidence to counter the unverifiable claims of random commenters?

This is not productive.

Evelyn aka CarbSane said...

@Carnivore: JM lost 170 lbs in 9 months in 1999 on a low fat diet. He gained it back binging/going off the diet. This time he's regained some 80 lbs eating pretty consistently low carb, that is not an insignificant amount of weight. The internet is littered with folks who gain on low carb.

You're tilting at windmills hoping for some mechanism by which excess fat calories are simply blown off if there are no carbs. The other study that I don't have time to look for now kept carbs at 150-ish and overfed up to 600g fat. They got a little sweaty at 400g and they didn't gain exactly 1 pound for every 3500 cal.

I guess if folks are happy that overeating on a VLC diet results in more fat turned to body fat I won't break up their party.

Sara said...

Argh, comment spammers! How annoying. Stephan, I suppose comment moderation would be too time consuming, with the number of comments your posts get?

As regards the study, I don't think the overeating was driven by nutrient deficiency as this would not develop in four days. Also, if we are to replicate what an average person has available to them (if that is what they were trying to do), shouldn't there also be things like fruit, sandwiches, salads and so on. Otherwise it could be that they were just eating to the usual volume (interesting point - was food volume measured?) and of course this would be higher in calories than the same volume of less processed stuff. Did they control for volume eaten?

As for the 'what things get stored as' argument, as far as I know, if it's not used - for energy, or for making bodily stuff (bones, hormones, etc etc.), then it is stored either as glycogen or as fat, or perhaps, in the case of amino acids, partially excreted.

What I've found is that I can lose the same amount of weight eating a certain amount of calories in whatever macronutrient ratio - I eat processed food rarely. The difference was that if carbs are too high and protein too low I just can't stick to it. Also, high protein/low carb seemed to work faster and better (at the same calories as a higher carb regime) in the short term but actually I was just playing with my body water.

Evelyn aka CarbSane said...

Fat feeding causes widespread in vivo insulin resistance, decreased energy expenditure, and obesity in rats

I'm efforting the full text on this one.

Adult male rats were pair-fed isocaloric diets high in either carbohydrate (69% of calories; HiCHO) or fat (59% of calories; HiFAT) for 24 +/- 1 days. Feeding of the HiFAT diet resulted in a greater than 50% reduction in net whole-body glucose utilization at midphysiological insulin levels (90-100 mU/l) due to both reduced glucose disposal and, to a lesser extent, failure to suppress liver glucose output. Major suppressive effects of the HiFAT diet on glucose uptake were found in oxidative skeletal muscles (29-61%) and in brown adipose tissue (BAT; 78-90%), the latter accounting for over 20% of the whole-body effect. There was no difference in basal metabolic rate but thermogenesis in response to glucose ingestion was higher in the HiCHO group. In contrast to their reduced BAT weight, the HiFAT group accumulated more white adipose tissue, consistent with reduced energy expenditure. HiFAT feeding also resulted in major decreases in basal and insulin-stimulated conversion of glucose to lipid in liver (26-60%) and brown adipose tissue (88-90%) with relatively less effect in white adipose (0-43%). We conclude that high-fat feeding results in insulin resistance due mainly to effects in oxidative skeletal muscle and BAT.

The BAT/WAT in rodents vs. humans is a big difference.

john said...

Carbsane,

From now on, if I suggest something I personally think, I'll use "I" instead of "we" or whatever to avoid confusion. I'll stop this little back-and-forth here, but every time somebody counters your arguments, you attack a loosely-related point or quote and then label that person a Taubes/Eades/etc lackey. Of course, you always finish it off with another non-logical yet condescending remark that humors only your own group of lackeys.

bentleyj74 said...

"Carbsane, Jimmy Moore got to 410 pounds eating the SAD."


I can't let that one fly Carnivore. His own reports of what his eating practices were like did not fit ANY profile other than binge eater on a permanent bender. He didn't have a renegade twinkie...he'd down a box or two at one sitting with a two liter of coke all to himself and that's just a snack. Remember though...gluttony has NOTHING to do with obesity. And that description doesn't resemble gluttony one iota. It's just that because of the carbs [you see] he didn't properly metabolize all those thousands of calories of healthy fats while being completely sedentary.

Duke of Earls said...

^As you say, the diet itself was bad, but worse was the food that set off the binge eating response. From my own experience, were I to eat such snack foods I'd likely do the same (well, not anymore, but back in the good ole' days before paleo dieting).

Someone can argue that fat can cause caloric gain all you want. I'm sure it does. I'm also sure that if one eats healthy fats and proteins with carbs mostly restricted to fibrous vegetables, binge eating is impossible. And as a former binge eater that's all I care about, and what lost me 80 lbs.

Asim said...
This comment has been removed by the author.
Asim said...

"When you eat a meal with starch in it, the glucose is absorbed into the bloodstream. Insulin released by the pancreas in response to the NORMAL rise in blood glucose will tell cells to take in more glucose and will decrease the release of fatty acids in order to favor burning glucose over fatty acids."

Dr. Harris,

1. What constitutes normal rise? Would this happen in a diet of any type of energy excess or one's where things like starches are reduced? This brings me toquestion 2.
2. What if we have a high-fat diet, with low carbs, meaning we are maintaining low blood sugar levels and minimal insulin production?

Travis,

"Few obese Americans take this route, but it should still be possible. You would just need to have a high insulin:glucagon ratio due to the constant presence of carbohydrates in meals/snacks coupled with a fairly large amount of dietary fat (that is shuttled to adipocytes) and very little activity, most of which simply results in glucose oxidation in the muscle mitochondria."

Isn't this the basic premise of the low-car dieters that take in high-amounts of fat, with 'moderate protein and lower carb? Without the carbs, the insulin and blood sugar take is "low", meaning one will ultimately have to use fat for energy, meaning it becomes the primary source?

Travis Culp said...

Asim: Lipids are always the default mitochondrial substrate and only shift due to carbohydrate intake and metabolic derangement. The mistake that a lot of people make is in thinking that it's the fat they're eating that results in "fat adaptation" when in reality it's the lack of glucose.

There is an amount of fat that zero carbers can eat that will cause body fat gain, but it's a lot more than for the average person since they're constantly oxidizing lipids and coverting them to ketone bodies for oxidation. This threshold can be pretty high if the individual is active.

Robert Andrew Brown said...

This is an interesting paper

Effect of carbohydrate overfeeding on whole body macronutrient metabolism and expression of lipogenic enzymes in adipose tissue of lean and overweight humans

http://www.nature.com/ijo/journal/v28/n10/full/0802760a.html

Robert Andrew Brown said...
This comment has been removed by the author.
psychic24 said...
This comment has been removed by the author.
Sue said...

yeh Jimmy Moore lost weight on low fat and on low carb through calorie restriction. He felt better losing on low carb - didn't feel hungry. But he started putting on weight again as believed that as long as he kept to low carb couldn't regain.
The way he became obese was not by eating the old food pyramid diet but by eating complete junk and lots of it.

eat well maine said...

This is an impressive site/ blog. Kudos to you.

But sometimes I think scientists fall prey to the reductionist approach; they overthink the problem rather than just observing what's going on out there in the world. This is the true genius of WAP's book. It's as much anthropolgy as science.

Gary Taubes' take on fat makes the most sense to me. Look at all those meat-based diets leading to true weight loss. I eat a lot of (good) saturated fat, few carbs, and I don't exercise that much. I have a lot of lean muscle; BMI is under 20%. I'm 61, but I weigh 40 lbs. less than I did a decade ago.

Ed Welles/ eatwellmaine.com

Stephen Boulet said...

Question: among hunter-gatherer populations eating their ancestral diet, is there a sweet spot in carbohydrate intake that associates with longevity?

Mike said...

First time reader. Great information. I will read much more.

Gadgetip said...

There is definitely worse out there...I usually read up on these things before committing to any type of diet. There's a great site called http://GetYourDiet.com that talks about the hottest new weight loss trends. My favorite is http://GetYourDiet.com/review/xtreme-fat-loss-diet/

Gadgetip said...

There is definitely worse out there. I usually read up on these things before committing to any type of diet. There's a great site called http://GetYourDiet.com that talks about the hottest new weight loss trends. My favorite is http://GetYourDiet.com/review/xtreme-fat-loss-diet/

Carnivore said...

Carbsane, forgive me for not doing my homework on Jimmy Moore, I'm not really a fan.

Either way, a formerly obese person regaining weight on low carb simply reinforces the fact that his/her metabolism is screwed. It does not establish the fact that low carb overfeeding can lead to obesity in the first place. Every example on the internet would be similar. Find me one person who originally GOT OBESE while restricting carb intake.

Rat studies don't really mean much, but again, 59% fat doesn't tell us what the CHO content was, I'm betting it would still be high in absolute terms. That's why percentages are misleading.

It's an established fact among bodybuilders who eat LC that you can 'overeat' by a significant amount and not gain bodyfat. I'm not tilting at windmills hoping for it, I know for a fact that it DOES happen because I've been doing it myself for the best part of the year now. What I do want is the mechanism to be studied.

bentleyj74, again, forgive me for not knowing Jimmy Moore's life history. I didn't think it was extremely relevant to the point I was making. Whatever junk he was eating or binge-eating, wasn't LC. It was high carb and high fat which everyone agrees will make you fat. No one argues that excess fat consumption in conjunction with high carbs is a good thing. You talk about gluttony, what drives it? How about wildly fluctuating blood sugar? Try being gluttonous and restricting carbs at the same time.