Monday, September 8, 2014

Thoughts on the McDougall Advanced Study Weekend

For those of you who aren't familiar with him, Dr. John McDougall is a doctor and diet/health advocate who recommends a very low fat, high starch, whole food vegan diet to control weight and avoid chronic disease.  He's been at it for a long time, and he's a major figure in the "plant-based diet" community (i.e., a diet including little or no animal foods).

Dr. McDougall invited me to participate in his 3-day Advanced Study Weekend retreat in Santa Rosa, CA.  My job was to give my talk on insulin and obesity, and participate in a panel discussion/debate with Dr. McDougall in which we sorted through issues related to low-carb, Paleo, and the health implications of eating animal foods.  I was glad to receive the invitation, because I don't see myself as a diet partisan, and I believe that my evidence-based information is applicable to a variety of diet styles.  I saw the Weekend as an opportunity to extend my thoughts to a new community, challenge myself, and maybe even learn a thing or two.  It was particularly interesting to compare and contrast the Advanced Study Weekend with the Ancestral Health Symposium, which is more Paleo- and low-carb-friendly.

General Observations

The attendees were a lot older than AHS attendees.  I estimate that most of them were in their 60s, although there were some young people in attendance.

I don't place too much emphasis on peoples' personal appearance at conferences like this.  You don't know what a person's background, genetics, or personal struggles may be, you don't know how closely they adhere to the program, and you don't know to what degree a group of people might be self-selected for particular traits*.  But I will note that Dr. McDougall, his family, and many of the other starch-based/plant-based diet advocates tended to be extremely lean with low fat and muscle mass.  They also tended to have a healthy and energetic appearance and demeanor.  As I would expect, decades of exceptionally high starch intake hasn't made them obese or obviously ill.

Dr. McDougall and his family were extremely gracious, despite the fact that we clearly disagree on certain matters, and I was expected to air my disagreements to the crowd (to be clear, there are also many points of agreement).  Actually-- that was part of the point-- to bring in people with alternative, evidence-based viewpoints.  I didn't know Dr. McDougall before last weekend, so I didn't know to what extent he really wanted to give my views a fair shake, but in retrospect he was sincere.

I wasn't sure what to expect from the audience, since I was (among other things) defending the position that eating meat is natural for humans and can be part of a healthy diet.  There were a few furrowed brows here and there as I spoke, but overall people were gracious, welcoming, and seemed genuinely receptive to my views.  The beliefs I encountered from attendees ranged from evidence-based to the types of scaremongering you might find on an Internet diet forum.  For example, some of them seemed to be convinced that meat is full of parasites, and if we eat it (even cooked), we'll acquire those parasites.

I spent the better part of three days eating a diet prepared according to Dr. McDougall's specifications.  I was looking forward to the opportunity to try a new diet style.  Meals contained zero added fat, zero animal food, and focused on starchy whole grains, beans, and root vegetables with some colorful vegetables as well.  Potatoes are a central part of his diet and they appeared at every meal.  No alcohol was served, and the only caffeine was tea.

The food was low in calorie density and bland, although not unpleasant.  It's definitely a reduced-reward diet.  I had no problem eating it for three days.  I ate to fullness, but I'm sure I ate fewer calories than usual and lost a bit of weight.  I felt good and had no trouble with hunger or fatigue; in fact, my appetite seemed to be suppressed somewhat.  I experienced some mild digestive distress, perhaps from the large quantity of beans and onions in the food.  My sinuses also became a bit stuffed, which is unusual.  I'm not sure if that was related to the food, but it did clear up as soon as I returned home and began eating my usual diet.

Panel Discussion

The panel discussion/debate was between Dr. McDougall and I, and was moderated by John Mackey, co-CEO of Whole Foods.  The goal was to discuss/debate low-carb, Paleo, vegan, and other aspects of diet, and explore the reasons for the popularity of low-carb and Paleo.  We kicked it off by playing a news report on the recent low-carb vs. low-fat study, and the National Geographic video of an anthropologist claiming that the "real" hunter-gather diet is low in meat and high in starch (to see why other anthropologists tend to disagree with her, follow these links: 1, 2).

Dr. McDougall is baffled by the popularity of low-carb and Paleo.  To me, the popularity of low-carb boils down to two factors: 1) It's an exciting, contrary viewpoint.  People love to hear that the government and the ivory-tower eggheads were wrong.  The print media is struggling mightily right now to keep eyeballs on the page, and they seem to be shifting to increasingly sensationalist tactics to survive.  2) It can be effective.  Many people are losing weight and apparently improving their health using low-carbohydrate diets, and some of these people were failed by low-fat diets.  It wouldn't be so popular if it didn't have some level of effectiveness.

I explained the rationale for the Paleo diet, as well as the rationale for an agriculturalist/horticulturalist-type ancestral diet centered around starchy foods with a modest amount of meat, eggs, and/or dairy.  I wanted to present an ancestral option that bears some resemblance to what the audience is already eating.  I didn't have time to deploy the full ancestral argument, but I think I had enough time to make a compelling case for it.  I think the audience became more receptive when I explained that I wasn't advocating for a high-meat or low-carb dietary style as the optimal diet for humans.  Overall my contribution seemed well received.

I also made the point that seemingly diametrically opposed diet philosophies, such as low-fat, low-carb, Paleo, and vegan, can all cause weight loss and apparent cardiometabolic improvements.  What they have in common is that they all restrict something, they all eliminate most common junk foods, and they all make us think hard about what's going into our mouths.  In general, the more restrictive the diet, the more weight loss it causes, and typically the greater the metabolic improvement.

We went on to discuss my full-fat dairy paper, vegan diets for children, the genetic and digestive basis for dietary adaptation, and a few other topics.

John Mackey was a great moderator-- fair and tough.  Mackey is modest and unassuming but also sharp.  I'm sorry I had to miss his talk on Sunday, because I wanted to connect with my friends who had driven from San Francisco to hear my talk.  I entered the room just in time to witness people jumping to their feet in applause.  I look forward to watching the talk when it's posted online.

My Talk

I gave an expanded version of my 2013 AHS talk "Insulin and Obesity: Reconciling Conflicting Evidence".  I argued that the evidence supports the hypothesis that obesity increases circulating insulin, but is difficult to reconcile with the hypothesis that increased insulin leads to obesity.  Furthermore, the latter hypothesis, at least its most popular incarnation, is based on a superficial understanding of insulin biology.

The talk was well received, although it may have been a little bit too technical for a portion of the audience.  It's not hard to convince people that insulin doesn't cause obesity when they've been eating extremely high-starch diets for years and, if anything, have lost fat.

I was honored that my friends Drs. Lynda Frassetto and Ashley Mason (UCSF) drove up to hear me speak at 8:00 am on a Sunday morning.

Other Talks

Dr. McDougall presented first on Friday.  It was a good opportunity for me to learn about his views.  Essentially, he believes that humans are designed to eat a vegan, low-fat, starchy, whole food diet, although he acknowledges that humans have hardly ever been vegan historically.  Animal foods and added fats cause "food poisoning", and "the fat you eat is the fat you wear".  He believes that a low-fat/high-starch diet offers a metabolic advantage, in other words that you can eat more calories on this type of diet without gaining fat.  It's interesting to note the parallels between the low-fat and low-carb communities in this respect.  He thinks physical activity and other aspects of lifestyle are much less important than diet.  He recommends B12 supplementation, although somewhat reluctantly.

He and I may not agree on everything, but I do believe-- and the research backs this up-- that this type of diet can cause weight loss and improvements in cardiovascular and metabolic health.  They make the point, which is fair, that the typical low-fat diet that gets whupped by low-carb diets in controlled trials is a wimpy version of what they recommend.  Dr. Barnard's studies show that a very low-fat vegan diet causes more weight loss and metabolic improvement than a typical low-fat diet, and in fact the results he achieves look very similar to what is reported in low-carb diet studies.

It may sound counterintuitive, but there's even credible research suggesting that low-fat high-complex-starch diets can help type 2 diabetics achieve better glucose control and reduce insulin needs.  It's really interesting for me to encounter almost identical anecdotes from the low-carbohydrate crowd and the low-fat vegan crowd: I lost 100 pounds, got off my diabetes medications, my blood lipids are much better now, etc.  I'm quite convinced that many people do well on the McDougall diet, and more remarkably, that a significant number of people can stick with it and even seem to enjoy it.

On Saturday, I attended a talk by Dr. Neal Barnard.  Dr. Barnard is the president of the Physicians Committee for Responsible Medicine, which would be more aptly named the Physicians Committee for Plant-Based Diet Advocacy.  His activities are a mix of laudable scientific and public health achievements, and overzealous diet advocacy.  Some of his scientific claims were a bit facile, for example, that lipid stores in muscle cells cause insulin resistance, and that this is a direct result of eating dietary fat**.

Stanford Research Dr. Christopher Gardner gave an enjoyable, meandering talk that touched on his diet trials, as well as his forays into exploring what motivates people to make positive changes in their diets.  Apparently, most people aren't particularly motivated by health.  They're more motivated by immediate, positive gains like feeling better.

The Absurd Talk Award goes to Gary Null, who I had never heard of but apparently has a large following.  Null started off by bragging that he's the #1 quack on the website QuackWatch, which he interprets as evidence that the mainstream medical and scientific community is conspiring against him.  He went on to 'educate' us about how vaccines cause autism, and how he had developed cures for cancer, AIDS, and other diseases.

Null also claimed, hilariously, that his research had revealed that beans are actually a complete source of protein, and that he had submitted his findings to 400 scientific journals and none of them had so much as responded.  Ummm... I could send three pages of completely illegible jibberish to almost any journal in the world, and if I submitted it properly, I'd receive a response.  The response would be "no", of course, because my submission would be scientifically worthless.  Furthermore, are there even 400 scientific journals in the world that are interested in the amino acid composition of beans?  I doubt it, but maybe I'm just part of the conspiracy...  In any case, I have a newfound respect for QuackWatch.

On Sunday, I saw Dr. Dean Ornish speak.  Dr. Ornish gets some flack from the low-carb/Paleo community, but I actually appreciated his talk.  He believes that a comprehensive diet and lifestyle program, including a low-fat/low-animal food diet, is the best way to improve health.  I have no doubt that his program is effective, but that's not what I appreciated the most about his talk.  I appreciate his ongoing efforts to evaluate diet and lifestyle modification using the tools of modern science.  I also appreciate his thoughtful perspective on how to get people to comply with a healthy diet and lifestyle sustainably and compassionately.


I'm glad I attended, and I think it was useful for all involved.

If someone put a gun to my head and forced me to choose between the McDougall diet and the Atkins diet for the rest of my life, I'd probably choose the McDougall diet.  Most of the people I met seem to be aging gracefully on the McDougall diet, and I still feel there are questions to be answered about the long-term health impacts of Atkins-type diets.  I still have major reservations about a 100 percent vegan diet, however, particularly for children.

Fortunately, no one is putting a gun to my head, so I'll stick with my starch-based diet that includes lots of nuts and a moderate amount of olive oil, butter, meat, seafood, eggs, and whole dairy.

* It was disappointing to hear multiple speakers pick on the appearance of Dr. Robert Atkins, the fact that he died earlier than them, and the circumstances of his death.  From what I understand, there's a lot of uncertainty surrounding his health at the time of his death, but it was repeatedly implied that his diet caused him to have cardiovascular disease and contributed to his death (which was actually due to head trauma).

** Athletes have elevated muscle fat (intramyocellular lipid, IML) stores, yet also have exceptionally insulin-sensitive muscles.  In that case, increased muscle fat seems to be a positive adaptation to high energy demands on muscle tissue.  Obese people also have elevated IML stores, but in that case it's associated with insulin resistance.  So do the elevated IML stores themselves cause insulin resistance?  Probably not.  In the case of obesity, they're probably at least in part a marker of excess energy availability to muscle tissue.  When a cell is exposed to more lipid than it can burn, it accumulates IML but also lipid metabolites such as diacylglycerols, Acyl-CoAs, and ceramides, and these metabolites shut down insulin signaling as if the cell is saying "Stop sending in more energy!  I already have too much!"  How does this happen?  It's probably mostly a result of the failure of enlarged, insulin-resistant adipose tissue to adequately trap fatty acids, causing excessive fatty acid exposure of lean tissues.  When insulin sensitivity is measured by gold-standard methods, dietary fat doesn't seem to have much impact on insulin sensitivity until you get to the extremes.


Rian said...

Very interesting article. Thank you. I am committed to Paleo. I am so much healthier now that have I stopped eating wheat/grains.

Stephen How said...

If I had planned ahead, I would have attended the conference last weekend. Dr McDougall's "The Starch Solution" talk made it obvious that a starch-based diet with a little meat was a successful ancestral diet. I'm big on exercise, and have lost 25 kg in 13 months. I post sometimes on the McDougall message boards, but I get a lot of flack for being a "meat eater".

I think that the McDougaller's would ally with you over the nuttier wing of the low-carb/Paleo crowd, once they get a chance to read your work. Several McDougaller's post links to your posts here.

Jeremy said...

I wish the Advanced Study videos cost much less than $150. I would watch them, particularly your roundtable discussion and the John Mackey talk.

Daniel Bradley said...

Thanks for this moderate perspective Stephan -- it's much appreciated.

On the subject of Atkins-style diets from an ancestral perspective, have you seen this blog post ( on the Inuit diet? As I understand it, it argues that the Inuit obtained a nontrivial amount of carbohydrate calories (15-20% of total) from muscle and organ glycogen and prepared their meat in ways that maximized the preservation of this "animal starch", in the author's terminology.

I don't know enough biochemistry to evaluate the argument properly, but if the author is right, it would appear that not even the Inuit ate a zero-carb diet, and in fact they were trying to maximize carbohydrate in their diet. Personally I think the idea of a zero-carb diet is extreme, but there are still many out there who tout zero-carb as a legitimate -- if not the best -- option for long-term health.

Sunny Sattva said...

Thankyou very much for the detailed account of the ASW. I base my diet on Dr McDougalls work. Lol moment - that you found the meals 'bland'.I have come to appreciate 'bland' or plain meals since following this plan. One's taste buds become more sensitive and eating becomes a subtle experience. Vegetables sing and a true sweetness comes through, unadorned a deeper appreciation. There are many McDougallers who are hard core starch + veg only!! Tis a gift to be simple! Great blog.

Evgeny Rokhlin said...

Animal foods and added fats cause "food poisoning", and "the fat you eat is the fat you wear".

This strikes me as completely unscientific and ignoring the biochemistry, especially coming from a doctor. I mean, I can understand that the diet works for you, but that's not an excuse to be ignorant.

It's really interesting for me to encounter almost identical anecdotes from the low-carbohydrate crowd and the low-fat vegan crowd: I lost 100 pounds, got off my diabetes medications, my blood lipids are much better now, etc.

I watched "Lessons from the vegans" talk by Denise Minger recently and can recommend it - a lot of info I did not know before.

She explaied the paradox with an awesome diagram, where in the under 10% fat region "magic" happens, but in the above 75 or so % fat "other magic" happens. Totally worth watching. :)

Gretchen said...

I'm a strong supporter of low-carb diets for people with metabolic syndrome, diabetes, or severe weight problems. (Daniel should know that low-carb diets are not no-carb diets; most people on LC diets eat a lot of greens as well as cruciferous vegetables and some berries).

However, I agree with you that LC diets may not be best for everyone. Those without blood sugar problems may do well on higher carb diets.

I think the best diet is the one that a person can stick to, and in today's world in which low-fat is still mainstream, it's probably easier to maintain such a diet in social situations.

However, I think a person with blood sugar problems should begin with a LC diet. If that doesn't work well for that person, then try something else.

I do question statements that people with diabetes need less insulin with high-starch diets. Many people with type 1 diabetes do find that if they eat a lot of fat on Day 1, they'll need more insulin on Day 2. But if they eat a lot of carbs on Day 1, they'll need more insulin on Day 1.

brec said...

I had a little internal debate about whether to read this entry before my planned viewing later today of Stephan's appearances last weekend, decided in the affirmative, and am glad I did.

A personal note about to how I transitioned abruptly a couple of years ago from Paleo to McDougall-like eating intended for those (maybe Stephan?) not familiar with the work of Caldwell Esselstyn:

At age 66 -- active and not overweight -- I'd been eating high-fat low-carb for 2.5 years. A sudden episode of angina during routine treadmill exercise led to a diagnosis of severe and non-stentable stenosis in some primary coronary arteries. (I certainly do NOT attribute this condition solely to my Paleo period.) I was strongly advised to undergo a double bypass (CABG).

During some intensive research I (a) determined that in my particular case, published conclusions that CABG was superior to so-called optimal medical treatment did not apply; and (b) discovered the initial results of Caldwell Esselstyn in treating severe cardiac disease with diet. (For a list of Esselstyn articles, including his latest study with a much larger cohort, see here.) I elected not to have the bypass, and to eat as Esselstyn recommended (similar to McDougall's regimen).

If you're familiar with Ornish's work: Esselstyn's is similar in concept but is solely diet-based with no other lifestyle modifications; and Esselstyn's results are, in view, amazing -- and for me, totally convincing.

Some WFPB (whole foods plant-based) diet advocates such as Michael Greger are fond of saying something like, "show me ONE study where Paleo or any non-WFPB diet has been PROVEN to reverse heart disease." (Referring to regression of coronary artery stenosis.)

I believe that my life depends on a WFPB diet. But I still retain my subscription to Stephan's blog, initiated in my Paleo days, because I appreciate his science-based contributions.

Joe Mason said...

I followed the McDougall Diet for about 10 years thinking it was good for my heart. Overtime my triglycerides became borderline elevated, had chronic gingivitis, recurring mouth ulcers and increased abdominal fat. My father follows a Dr. Bernard style diet and has lost a significant amount of weight including muscle mass, but much lower LDL cholesterol and improved fasting blood sugar levels. His triglycerides are a bit high and his HDL and vitamin D levels are pretty bad.

I think our ancestors became adapted to high starch and low fat diet as a survival mechanism. Fluctuations in climate would have created conditions where a primarily starch based diet would have been the fallback food. Surviving and thriving aren't the same thing. Our ancestors didn't choose a low-fat or a low-carb diet out of preference. It was imposed on them by environmental conditions. Given the option many would have chosen a junk food diet. Instead, when plant and animal food were both relatively available they chose a mixture with a significant about of animal based food.

The loss of lean muscle mass on high starch low fat diets may be an adaption strategy for survival. A low fat and probably low protein diet would be indicative of a stressed environment diet, therefore conserving energy by pairing down muscle mass would lower caloric need for homeostasis. Having a very low BMI, especially with little reserve muscle mass, does creates some serious health offsets. On an optimal diet, you would expect leaness with significant muscle hypertrophy for functional strength and canibalic reserve.

Joe Mason said...

The high-carb and very high-fat diets would have been the outliner diets of our ancestors. High carb eating would have occurred as a fallback diet when game wasn't available. Very high fat eating would have only occurred under exceptional hunting success. The hunter-gatherer lifestyle is what it is, given reasonable access to both animal foods and plant foods labor was divided almost equally to exploit both.

Extended periods of high carb eating would have been indicative of food shortages and done as a survival strategy, and not by choice. The loss of lean muscle mass on high carb diets (often low in protein), especially on calorie restriction, is a survival mechanism to reduce basal metabolic cost. This adaptation is for survival, and not by any means optimal. Primates and humans in their optimal natural state have significant hypertrophy for functional strength and substrate reserve. Only in the modern seditary era can we voluntarily avoid animal foods and remain "relatively" healthy and skinny.

Oliver Magoo said...

I'd like to see all of these presentations but for $150 ?? I guess I'm stuck with Ancestral Health Symposium videos.

Aaron said...

Here's one thing a lot of people don't consider. Why not keep fat low for a while and then creep fat intake up a bit and then let it go down randomly. We are not machines, variety in intake is probably more healthy than one set pattern.

Andrew Rowe said...

I attended the weekend and enjoyed the debate and your presentation. I was surprised to read your impression that Dr. McDougall "recommends B12 supplementation, although somewhat reluctantly." Having been through his 10-day program and seen him speak several times, my impression is that it is a demand given with no hesitation at all.

He does believe that all other isolated supplements/vitamins fall somewhere between useless and dangerous, but he always mentions the B12 exception to that.

McDougall food is bland, especially if you don't realize they cook with little to no salt. They expect you to add it at the table where you'll taste it more while consuming less. I'm a little surprised they didn't mention that before the 1st meal.

I'm a proud McDougall anecdote. Following his plan certainly changed the trajectory of my health.

I'm glad I was exposed to your work over the weekend. I look forward to adding your blog to my regular reading list.

Henry Campbell said...

Joe Mason, how do you know all of that? Were you there? Did you go back in a time machine and study them? This is why I dislike arguments based on our Paleolithic ancestors. They're just too speculative, and more often than not, a just-so story to rationalize the person's preconceived notions about diet.

Chris L said...

I've read quite a few diet books, ranging from vegan to Paleo but McDougall is one I hadn't gotten around to reading. I downloaded his latest book and am working my way thru it now.

I'm skeptical that, as a recently diagnosed Type 2 Diabetic, a high-carb diet could work for me. So far, his book hasn't directly addressed diabetes and I'm to the implementation chapters.

I may give this one a shot because I would MUCH rather eat a starch based diet than a low-carb diet.

Unknown said...

I've been on and off the McDougall diet for over a decade. I notice a lot of things improve, such as sleep, and I feel much more energetic and grounded. Mood overall greatly improves. I can't stress enough how good I feel, and any other diet I've tried doesn't get me to the same high. It has however seemed to cause more joint pain for some reason, something for which I've seen Dr. McDougall recommend cutting out wheat. It also causes digestive issues, that I adjust to if given the time. Unfortunately, and especially since I became a parent, I eat crappy every weekend and have become a "yo-yo" dieter, something my digestive system really doesn't like. Maybe gut biome related. I've often thought adding a bit of animal products and fats to this diet would be the way to go for me personally.

Anyhow, there is still so much more still to learn here, and I'm much appreciative of Dr. Guyenet's contributions.

James Brown said...

I wish someone would inform the long lived Okinawans, whose diet was around 5% animal products about the dangers of a plant based diet. The data is clear, the lower the % of animal products in the diet the healthier the people. Wake up!

psychic24 said...

Hi Stephan,

I was wondering how many nuts you eat as you said you eat "a lot of nuts" in your main diet. Also typically what kinds?

anapricot said...

Super interesting. I can't imagine 90% of low-carb bloggers being as fair as you are when facing different views.
I'm growing interested in McDougall as the months go by. As you said in this post the successful members of the McDougall site forum seem so.. satisifed. Like a Buddhist detachment of food. Some have extremely simple diets (such as plain brown rice and veggies almost every meal). This is almost impressive.
I admit to being a very good cook and think it's crazy the way they eat but the idea grows on me. In any case it's a good illustration of Food Reward ideas (the vegan thing stays BS though).

anapricot said...

I forgot to add that the McDougalls are very keen on making the diet as easy as humanely possible (its admittedly very hard to follow if you eat out often). They do not get super orthorexic about stuff like microwaves, types of fruit/veggies, types of bread, etc like other types of diets (Paleo is alright but the costly obssession of coconut oil/ghee/pastured & grassfed everything simply eliminates alot of people who were interested in eating better in the first place).
McDougall has a lot of simple hacks like bake/cook potatoes $ veggies in microwaves, use low-sodium canned beans & tomatoes, etc. They are very sensible and can appeal to a wide base of people who are willing to change their eating.

Stephan Guyenet said...

Hi Stephen,

Congrats on your impressive weight loss. As acknowledged by Dr. McDougall, all (or almost all?) healthy starch-based traditional cultures ate some animal foods.

Hi Daniel,

I have a hard time imagining how the Inuit could have gotten that much carbohydrate on a regular basis. But in any case, their diet was an outlier from an ancestral perspective. They did fine, but I doubt it was an ideal diet. I think the Inuit were only Inuit for not much longer than humans have been cultivating plants for agriculture. That said, I'm sure they did try to maximize the carbs in their diet. They went to great lengths to harvest berries and tiny little tubers, though availability was limited enough that their calorie intake from these sources was modest.

Hi Gretchen,

Thanks. My comments regarding carbohydrate and diabetes were specifically about type 2 diabetes, and particularly early-stage where there is still some beta cell functionality. Type 1 diabetes is not going to be improved by a high-carb diet, at least it's extremely difficult to imagine mechanistically.

Hi Brec,

The STARS atherosclerosis study is a non-plant-based-diet RCT that demonstrated regression of coronary artery narrowing in many of its subjects, and a highly significant drop in cardiovascular events, with diet alone (as opposed to the Ornish studies which used a comprehensive diet and lifestyle approach). The intervention was a multi-factor whole-food-based "lipid-lowering" diet with increased fruit, veg, fish, nut intake, and decreased processed food. STARS was published in 1992. A follow-up study of Shai et al also showed that all three diets, including low-carb, led to a decrease in carotid artery intima-media thickness. I realize that the relationship between CIMT and cardiovascular events has been questioned, but that still suggests a reduction of artery wall thickening in a major artery.

Hi Andrew,

Thanks. My comment that Dr. McDougall seems a bit reluctant about B12 is based on comments he made to me. I could be wrong, but my impression is that he thinks the risk of not supplementing is overblown. He stated that functional B12 deficiency is extremely rare.

Hi James,

Don't you find it interesting that the traditional Okinawan diet, and all other healthy-starch-based cultures, includes animal foods?

Hi psychic,

I don't quantify, but I eat a few handfuls of almonds per day. I also eat peanut butter pretty frequently these days.

Hi anapricot,

I agree. I don't write about cooking much, but I do tend to microwave my taters because it's so convenient and they turn out fine. I have yet to encounter any compelling reason not to microwave.

Joe Mason said...

Henry Campbell, you are right I don't know those things by first hand observation. In fact no one does, but that doesn't end the discuss or exclude other types of evidence. We can draw inferences from other indirect evidence. If x+1= 4, then I can deduce x=3. Every health study that relies on statistical analysis takes data and tries to find meaningful patterns that are not necessarily obvious or directly observable.

You may not like evolutionary type arguments, but without that context ancestoral diets have no meaning or relevance. Just so arguments are not enough, but without an evolutionary biology framework then every diet argument is a "just so" argument. We can just cherry pick the data we like and then say, "See I'm right." Evolutionary theory requires us to know (or try to know) the who, the what, the where, the when and the why in regards to biology questions.

Chris MacAskill said...

13 years ago I adopted the Paleo diet and it helped me lose 33 pounds and keep them off for the 3 years I ate that way. I suspect that losing the donuts, cookies, and refined breads made the biggest diff. And I felt pretty good, just a little hungry at night.

One issue for me is my cholesterol started at 238 and after the 3 years and all the weight loss, it ended at....238. Neither I or my doctor could believe it.

I also like to do triathlons and fueling with greens, berries and meat just seemed impossible. You die out there. And I couldn't shake my acid reflux.

So I dove into the research and I have to say, for preventing heart disease, type II diabetes, acid reflux--and endurance sport performance--the data is overwhelmingly on the mostly plant eater's side.

So I tried that 10 years ago. My weight or muscle mass didn't change but I started winning my age group in triathlons, cholesterol went to 171, the acid reflux went away, and I wasn't hungry at night or getting carb cravings I couldn't satisfy. Nothing feels better to race on than a bowl of oatmeal, and nothing satisfies like brown rice and beans with salsa after.

I just had my heart imaged (heart disease runs in my family) and it's clear of plaques and calcification, Blood sugar, blood pressure, triglycerides and blood sugar are all lower than they have ever been, and I'm 60.

I must have two dozen friends who are body builders, triathletes, etc., who only eat plants, and they have great muscle definition and low body fat. You don't see world class endurance athletes eating a lot of meat.


Char said...

Very interesting write up. Thank you Stephan. It's nice to see people that don't totally see eye to eye on all matters work together on the things they can learn from each other. Refreshing, for sure.

Gretchen said...

@Chris, This is a good example of the fact that a dietary regimen that works wonderfully for one person may not work at all for another.

Some people find the opposite of what you found. The carbohydrate-focussed diet didn't help and seemed to hurt and the LC diet did everything you said your "plant-based" diet did.

Some athletes have, in fact, switched to low-carb diets and find that their performance improves.

So the trick is to figure out what works for *you.* I'm glad you discovered that.

EEH said...

Wow, I just went and read the McDougall's diet program and it's really dramatically lowfat! I felt hungry reading it. A year ago my family moved to West Africa and we went from eating a Weston-Pricey style diet to eating a very reduced protein, high carb, dairy free diet typical of our region. We almost starved (I'm really slender naturally and I lost twenty more pounds) the first few weeks of living on this diet until we figured out the locals secret to survival which is the copious use of unrefined palm oil in their cooking of vegetables.

Before we noticed that, even eating a supposedly hearty food like potatoes for dinner would leave me so hungry I couldn't sleep. One night I eventually got out of bed shaking with hunger and dug up a jar of peanut butter we were saving as a treat (imported and very expensive) and ate the whole thing with a spoon.

I just assumed after this experience that native high starch diets must use some sort of fat otherwise they'd just waste away. Part of our dramatic hunger was caused by our increased daily exercise through walking, usually 2+ miles a day. Most local people though have dramatically farther walking commutes than we do and do heavy farm labor on the top of it. I don't think they could do it with out the fat from the oil to sustain them! So anyway McDougall's diet doesn't really ring true to my experience/observation, maybe it would work for people who weren't expending a lot of energy?

Robert Andrew Brown said...

HI Stephan

Your thought provoking posts are always appreciated.

Trowell and Burkitt Western Disease, of which I know you are aware, has an interesting chapter page 373 on high Fibre diets and diabetes2.

The results are very thought provoking.

Total fat intake was 18 grams per day v 74 grams per day for the control group.

The diabetic high fibre group were able to significantly reduce insulin usage.

Ned Kock said...

Nice summary Stephan. It is nice to see that, after a significant amount of time blogging, you are still genuinely interested in finding the truth - not matter where it takes you. This is the most defining characteristic of a "true scholar"!

brec said...

"The panel discussion/debate was between Dr. McDougall and I ..."

Why no, it was between Dr. McDougall and me.

Hmm, wait, I wasn't there -- I saw it on video. Now I'm confused. ... Does a starch-based diet cause carping on grammar? Maybe the NIH will fund a study.

brec said...

Stephan - just a note of thanks for the STARS study pointer. $35.95 later [cough] it does appear to show some regression on a much higher (27%) fat diet than McDougall's/Esselstyn's.

Related note: anyone know if there's some kind of non-studen membership or subscription service that provides access to science articles/studies that would be cheaper than $35 several times a year?

ICG said...

A very good and informative post. I second the recommendation for Denise Minger's recent Youtube video ("Lessons from the Vegans"). She's one of the most fair-minded folks from the paleo/ancestral camp.

I have a question about this statement: "Dr. McDougall, his family, and many of the other starch-based/plant-based diet advocates tended to be extremely lean with low fat and muscle mass."

Are you saying they have low muscle mass...or they're very lean yet have adequate muscle mass? I've never been vegetarian/vegan, but I've started eating that way about 80-90% of the time. (The other meals include meat and/or dairy.)

My biggest question has been protein consumption. How much do you really need for health and satiety? I've heard so many different rules of thumb based on grams per body weight, grams per lean mass, etc. Of course, the vegans say you need much less than the paleo/low-carb crowd claims.

I could use protein powders, but really like to stick with whole foods. I'm not a bodybuilder or even a weight lifter, but do a lot of bodyweight exercises and have a fair amount of lean muscle mass to support. Thanks for any insight about this.

Gretchen said...

@ICG The Eades book Protein Power has interesting photos of one man, a runner, as he went from low-fat with carb loading before running (very thin), to no diet and no running (fat), to a muscle-building phase on low-carb (well muscled), to now, when he doesn't do a lot of exercise but appears to have maintained muscle.

On the LC diet he wasn't as thin as on the low-fat diet, but he looked better muscled.

Stephan Guyenet said...


They tend to have low muscle mass. Neal Barnard looks like he's starving, and a number of others looked similar.

I think part of it is the low-calorie-density diet that's lower in protein, and particularly lower in high-quality protein, and part of it is the fact that they don't emphasize exercise. In particular, there seemed to be very little interest in strength training.

They are correct that the human protein requirement is considerably less than what we get in affluent nations, but the lower you go, the less you're supporting your muscle mass and physical performance.

Tim said...

An intriguing question is whether a very low protein intake (particularly low in methionine and BCAA) will provide them with a longevity benefit similar to caloric restriction, as first suggested by Martin McCarthy[1]. His hypothesis has recently been corroborated by the Cell paper by Levine and Longo[1], which was - not surprisingly - well reveived within the vegan community but largely ignored within the paleosphere. Maybe it's a good idea to eat a low-protein plant based diet between adolescence to senescence but a higher protein diet in young and old age?

In case reads this aking himself: what the hell is he writing about? Rhonda Patrick gives a nice explanation in one of her YouTube videos[2].


tomR said...

How would such diet affect the rate of replacement of fat in fat tissues (slowing down perhaps?), especially as compared with diet with carboless breakfasts/later compensating?
What I mean if someone wants just to replace his fat in the tissues with new, healthier one - wouldn't frequent supply of starches make it slower?

Honey Razwell said...

Hi Stephan,

Very nice article. I think of the lot, Dr. Ornish is the most reasonable and knowledgeable. I have a new found respect for him. He has recently penned an article for Edge about ideas ready for retirement. Namely, his was the erroneous view that the randomized clinical trial is the only reliable method.

There are always millions of variables present with human beings -even when we can tweak the knobs a bit more. It is only one method of testing an idea. Useful, but there are many situations in medicine where these studies do not tell physicians what they need to know or what patient will benefit.

In other words, many situations where they are very limited to useless even.

****In science, we should have MANY independent and different multiple techniques and methods to test an idea, as science educator, Alexi Filippenko stresses. Filippenko also stresses that even with all these different techniques to test an idea, and all their systematic errors it STILL could lead to a wrong conclusion. But it is less likely and our confidence grows. Too many Bloggers do not acknowledge science's limits, including vegan and low-carb dogmatic medical doctor zealots. ****

For instance, if there is a Multiverse, we know that it is there, but never know it directly- like the fish in the river unaware of our world. or astronomers of the future unaware of the Big Bang. We could be in this same position right now, missing many important observables when Earth was formed which limits what we can even ask about.

Science is wonderful, but it does have its significant limits. We do not "see" the warping of space fabric ( just an eclipse with a dot here rather than there), nor the origin of species ( just rocks with finches), nor the nuclear reactions inside of stars- YET we know about them. There was something horribly inadequate with Empiricism from the start. It is not alllll wrong, but scientific knowledge is not derived from the senses. We need a lower case "e".

Scientists are still unraveling how cells work. We have a long way to go.This has HUGE implications for the field of medicine - and nutrition as well. I wish Dr. McDougall and others in vegan and low-carb community would admit that a lot of uncertainty exists about diet.We are all taking risks. The ideal human diet probably does not exist. if it does we are nowhere near knowing it. Only salesmen pretend we do.

Take care,Stephan

Paul Verizzo said...

I read this and all the comments yesterday, and had viewed Minger's talk about what paleo's can learn from vegans (and those magic zones!)

I'm afraid that the good doctor suffers from a syndrome I've noticed over many decades: Very smart, well educated, mostly righteous conclusions.....and then, one day, off of the rails.

How could any diet we are "designed for" require modern farming, modern transportation, and of course, hold that B12? How many plant foods are or have been around in the wild in any given location that would support healthy human beings evolving? Answer: It would be very rare, even if over several hundred square miles.

Or, if as many people note of these vegans, how would they have escaped predators, crossed mountains and rivers? Answer: They wouldn't have been able to, hence we were not "designed" for this diet.

Something I would like to see researched is all causes mortality of these adherents. I'll bet it's terrible. Sure, they may escape CHD, but what about infections? Vitamin deficiency results, especially fat soluble vitamins? We already know that very lean people are much more likely to die when hospitalized for whatever reason. (Like getting hit by a car because they couldn't move out of the way, perhaps?)

Most animals instinctively know what to eat and very much like to eat what is proper. Why would one have to force themselves to eat a bland, unflavorful, "oh, gee, but after awhile you get used to it. Like having no libido, it's very liberating." Answer: Because we were not "designed for" such a diet.

I do think, especially after watching Minger's video, that the dietary extremes are often good interventions. In fact, the evidence very much supports that observation. However, except perhaps in rare cases, they should not be long term diets for most people.

Like with Minger's work, I thank you for a rational alternative view, Stephan.

Deanna said...

McDougall serves the food low salt, probably for those who have salt-sensitive hypertension and gives salt shakers to individually meet taste bud requirements. I find the low-fat diet fabulous. Try any traditional plant-based food recipes across the globe: Indian curried chickpeas, Japanese miso, spicy three bean chili, or Mediterranean minestrone-no blandness here. Not a cook, try McDougall's soups on the shelves. My favorites: minestrone, black bean, roasted tomato and split pea. Super healthy fast food!!

Also, for the woman who wants starch as a type 2 diabetic. Check out Dr. Barnard's, Prevent and Reverse Disabetes. At 60, I think Dr. Barnard looks fantastic-doesn't look too lean to me- just an ectomorph body type. At 80, Caldwell Esselstyn is still a head turner!! But more important, than the looks on the outside, is that their diets knock vascular disease and diabetes to its knees. Lose the weight and keep your arteries supple, plaque-free and keep your insulin sensitivity with a whole-foods low-fat plant based diet.

David Wildman said...

Enlightening article!
However, the "bland" comment - while his accurate observation of the way the food was presented to him - is not the way this eating regimen has to be at all. There are numerous ways to herb / spice / flavor / combine foods, etc. to make the food taste quite good. I should say that I also enjoy the natural subtle flavors of the food itself independent of the ways to punch it up.
I have lost weight on high meat/ high protein / high fat, very low carb as easily as I did on this plan with one major exception: I find I am not missing the meat and dairy nearly as much as I thought I would and I find that you can actually eat until satisfied and will never be hungry unless it's time to eat again. Eat when hungry. Stop when not. (up to 20 minutes sometimes to realize that) Simple as that.
Ultimately, I don't believe I can do entirely without meat, fish, yogurt and nuts, so I am staying on the McDougall Plan with only very minimal cheats until I lose all exess weight, then will add a little of these other foods while on maintenance. I can always revert to plan if the scale ever creeps up and know that I will get back to target weight without hunger! Couldn't say that with most things I've tried.
Might end up close to a McDougall-Mediterranean hybrid. Only time will tell.
Due to significant musculature, I will achieve a ripped, muscular physique at 64!
It's great to have a tool to achieve target weight relatively easily wile improving metabolic factors / blood work.

sarahjan said...

Hi! No idea if you still respond to comments on older articles like these, but I am curious on your thoughts about the high grain consumption in this style of eating without (it seems to me) much processing, fermenting, etc. My personal opinion about grains is that it probably doesn't matter so much if you're not getting every single mineral from your bowl of oatmeal if you aren't relying on oatmeal for everything, but in a high-starch diet like these, do you risk nutrient deficiencies without things like fermentation? Is anyone in this part of the health world focused on questions about preparation methods?

Comfortably Convincing said...

last i thought the overall consensus advice was for low fat dairy products not whole and butter (like you made sure to point out in your last sentence). much in the same way no one that's educated believes black beans are a complete protein like you said of that quack. so honestly i think every educator is right about some things and full of shit about others. I guess Im gonna take the truths from all of these "experts" and move on with my life

Paul Spring said...

I wonder what you base your dismissive comment on Dr. Barnard's discussion on fat being the cause of insulin resistance. From what I've read there is clear evidence that he is correct. See, for instance:

Stephan Guyenet said...

Hi Paul,

Please see the second asterisk at the end of the article, where I discuss this. Intramuscular fat itself (as in triglyceride) may not be a causal factor in insulin resistance.

Rather, the accumulation of products of incomplete fatty acid metabolism that occur when you have too much energy coming in and not enough leaving, like ceramides and DAG, are more mechanistically linked to insulin resistance. So my view is that it's not about the absolute quantity of fat available, but the amount available vs. the amount your tissues are consuming. Bad things tend to happen when your tissues are overloaded with energy (whether from fat or glucose), e.g. in obesity, overeating, or being sedentary.

Calogero Fiore said...

Mcdougal advocates a low fat high carb diet, I'm wondering if this can benefit fatty liver and cholesterolosis (gallbldder polyps)
Do you guys hve any ideas? Thanks.