Public Talk at the University of Virginia on Friday, January 17

This Friday, I'll be giving an invited lecture at the University of Virginia, my undergraduate alma mater.  I was kindly invited by a medical student named Robert Abbott, and it worked out well because I was already traveling to Charlottesville.

The talk will be titled "Why Do We Overeat?  A Neurobiological Perspective".  Here's the teaser:

Obesity is a leading cause of morbidity and mortality in industrialized nations, yet this is a relatively recent phenomenon.  In the United States, increasing obesity prevalence has paralleled a gradual increase of daily energy intake.  Why do most Americans eat more than we used to, and more than we need to maintain a lean state, despite negative consequences?  This presentation will touch on the neurobiology of action selection, the neurobiology of energy homeostasis, and why our central nervous system hardware may not be up to the task of constructively navigating the modern food environment.

The talk will be attended by medical students, but I also hope to have some doctors and researchers show up, as well as people from the broader Charlottesville community.  It will be a thought-provoking talk regardless of your background, and it will touch on some of my own work.

The talk will be held in the main medical school auditorium, MEB 3110, on Friday, January 17 at noon.  You can find driving directions and parking information by following this link.  You'll probably have to park in a parking garage, either the Lee Street or Central Grounds garage (directions in the link).

For a map of the UVA health system, follow this link.  The Medical Education Building is number 44 on the map, and the talk will be in room MEB 3110 on the 3rd floor of the building.

See you there!

Free e-Book and Ideal Weight Program 2.0 Announcement

I'm happy to announce that we're releasing a free e-book titled Why do We Gain Fat, and How do We Lose it? An Introduction to the Science of Body Fat, by Dan Pardi and myself. This is a slimmed-down version of the longer, fully referenced e-book we offer as part of the Ideal Weight Program. In it, we provide a succinct overview of the science of body fat gain and loss, and the evidence base for our program.  It also contains a schematic that ties together the various concepts in visual form. You can download it from the Dan’s Plan site by following this link to our program overview page.

Ideal Weight Program 2.0 Upgrades

Over the last year, Dan and I have been working hard to improve the Ideal Weight Program, both in response to user feedback and our own ideas for development.  Here are some of the new features we offer in 2014:

1. Four-week meal plans and shopping lists for the FLASH diet and the Simple Food Diet, as requested by Ideal Weight Program users.  This is in addition to the recipes and cooking guides we already provide.  
2. The Protein Unit system.  Research suggests there's an optimal amount of protein for appetite control and fat loss, depending on your height, weight, gender, and physical activity level.  Our fat loss diets are high in protein, but how do you know you're getting the right amount?  We've created a calculator that does it for you automatically, and explains how to apply your personalized Protein Unit value easily and intuitively using real food. 
3. Diet plates.  These are visual guides to following our diets, based loosely on the intuitive USDA MyPlate design.  
4. Cheat sheets.  Put these on your fridge to remind yourself of your diet and lifestyle guidelines, and daily protein unit goal.
5. Updated guidance.  We've refined a few things in the diet guidance documents. 

At a time of year when many people want to shed excess holiday pounds and start down a leaner, healthier path, we offer the Ideal Weight Program 2.0.  The program comes with a 30-day no-questions-asked refund policy so you can try it without risk.  We think you'll love this program, but if it doesn't work for you, we're happy to refund your purchase price. 

Financial disclosure: I receive a portion of the revenue from the sale of the Ideal Weight Program.  I do not receive revenue from the sale of other products associated with Dan's Plan or the Ideal Weight Program (such as the Fitbit, cooking tools, and other programs).

Does the Vitamin and Mineral Content of Food Influence Our Food Intake and Body Fatness?

The Claim: We Overeat Because Our Diet is Low in Vitamins and Minerals

We know that animals, including humans, seek certain properties of food.  Humans are naturally attracted to food that's high in fat, sugar, starch, and protein, and tend to be less enthusiastic about low-calorie foods that don't have these properties, like vegetables (1).  Think cookies vs. plain carrots.

In certain cases, the human body is able to detect a nutritional need and take steps to correct it.  For example, people who are placed on a calorie-restricted diet become hungry and are motivated to make up for the calorie shortfall (2, 3).  People who are placed on a low-protein diet crave protein and eat more of it after the restriction is lifted (4).  Humans and many other animals also crave and seek salt, which supplies the essential minerals sodium and chlorine, although today most of us eat much more of it than we need to.  At certain times, we may crave something sweet or acidic, and pregnant women are well known to have specific food cravings and aversions, although explanations for this remain speculative.  Research suggests that certain animals have the ability to correct mineral deficiencies by selecting foods rich in the missing mineral (5).

These observations have led to a long-standing idea that the human body is able to detect vitamin and mineral (micronutrient) status and take steps to correct a deficit.  This has led to the secondary idea that nutrient-poor food leads to overeating, as the body attempts to make up for low nutrient density by eating more food.  In other words, we overeat because our food doesn't supply the micronutrients our bodies need, and eating a micronutrient-rich diet corrects this and allows us to eat less and lose body fat.  These ideas are very intuitive, but intuition doesn't always get you very far in biology.  Let's see how they hold up to scrutiny.

Food Reward Friday

This week's lucky "winner"... peanut M + M's!!!

Does "Metabolically Healthy Obesity" Exist?

Obesity is strongly associated with metabolic alterations and negative health outcomes including diabetes, cardiovascular disease, and some types of cancer (1, 2, 3, 4).  Excess body fat is one of the primary causes of preventable health problems and mortality in the United States and many other affluent nations, ranking in importance with cigarette smoking and physical inactivity.  Obesity is thought to contribute to disease via the metabolic disturbances it causes, including excess glucose and lipids in the circulation, dysregulated hormone activity including insulin and leptin, and inflammatory effects.  This immediately raises two questions:

1. Does metabolically healthy obesity exist?
2. If so, are metabolically healthy obese people at an elevated risk of disease and death?

Does metabolically healthy obesity exist?

Food Reward Friday

This week's lucky "winner"... Oreo cookies!!!

Beans, Lentils, and the Paleo Diet

As we continue to explore the foods our ancestors relied on during our evolutionary history, and what foods work best for us today, we come to legumes such as beans and lentils.  These are controversial foods within the Paleolithic diet community, while the broader nutrition community tends to view legumes as healthy.

Beans and lentils have a lot going for them.  They're one of the few foods that are simultaneously rich in protein and fiber, making them highly satiating and potentially good for the critters in our colon.  They're also relatively nutritious, delivering a hefty dose of vitamins and minerals.  The minerals are partially bound by the anti-nutrient phytic acid, but simply soaking and cooking beans and lentils typically degrades 30-70 percent of it, making the minerals more available for absorption (Food Phytates. Reddy and Sathe. 2002).  Omitting the soaking step greatly reduces the degradation of phytic acid (Food Phytates. Reddy and Sathe. 2002).

The only tangible downside to beans I can think of, from a nutritional standpoint, is that some people have a hard time with the large quantity of fermentable fiber they provide, particularly people who are sensitive to FODMAPs.  Thorough soaking prior to cooking can increase the digestibility of the "musical fruit" by activating the sprouting program and leaching out tannins and indigestible saccharides.  I soak all beans and lentils for 12-24 hours.

The canonical Paleolithic diet approach excludes legumes because they were supposedly not part of our ancestral dietary pattern.  I'm going to argue here that there is good evidence of widespread legume consumption by hunter-gatherers and archaic humans, and that beans and lentils are therefore an "ancestral" food that falls within the Paleo diet rubric.  Many species of edible legumes are common around the globe, including in Africa, and the high calorie and protein content of legume seeds would have made them prime targets for exploitation by ancestral humans after the development of cooking.  Below, I've compiled a few examples of legume consumption by hunter-gatherers and extinct archaic humans.  I didn't have to look very hard to find these, and there are probably many other examples available.  If you know of any, please share them in the comments.

To be clear, I would eat beans and lentils even if they weren't part of ancestral hunter-gatherer diets, because they're inexpensive, nutritious, I like the taste, and they were safely consumed by many traditional agricultural populations probably including my own ancestors.

Extensive "bean" consumption by the !Kung San of the Kalahari desert