Thursday, February 13, 2014

Mindless Eating

You think you're in control of your eating behavior-- but you aren't

In 2005, Brian Wansink's research group published a remarkable study that demonstrates the powerful unconscious influence of the food environment on our consumption (1). 

Volunteers were invited to a test kitchen to eat bowls of tomato soup for lunch.  Each person was given a bowl containing 18 ounces of soup-- but there was a catch.  Half the volunteers were given custom-made soup bowls that partially refilled as they ate, such that the soup level dropped more slowly.
Read more »

Tuesday, February 11, 2014

5 Easy and Effective Ways to Eat Less

Why do we overeat?  Why is it hard to lose fat once we've gained it?  Is there a way to comfortably and sustainably eat less and lose fat? 
 
I recently did an interview with Armi Legge of Evidence Magazine that gives an overview of my thinking on these topics-- based on a large and compelling body of research that rarely reaches popular media sources in useful form. 
 
At the end of the interview, Armi asks me to list my top five tips for reducing calorie intake.  Enjoy!
 
 
 

Thursday, February 6, 2014

Mysteries of Energy Balance and Weight Loss

How to Lose Weight Effortlessly
 
You've probably seen this claim many times: a pound of fat contains 3,500 kilocalories (kcal).  A slice of toast is 80 kcal.  All you have to do is forego one slice of toast per day-- just a few percent of your total calorie intake-- and you will lose 8.3 lbs of fat per year.  Fat loss is so easy!
 
This reasoning is extremely common both in the popular media and among researchers.  Here's an example from the otherwise excellent book Mindless Eating, by researcher Brian Wansink:
...the difference between 1,900 and 2,000 calories is one we cannot detect, nor can we detect the difference between 2,000 and 2,100 calories.  But over the course of a year, this mindless margin would either cause us to lose ten pounds or to gain ten pounds.  It takes 3,500 extra calories to equal one pound.  It doesn't matter if we eat these extra 3,500 calories in one week or gradually over the entire year.  They'll add up to one pound.
This is the danger of creeping calories.  Just 10 extra calories a day-- one stick of Doublemint gum or three small Jelly Belly jelly beans-- will make you a pound more portly one year from today.  Only three Jelly Bellys a day.
According to this reasoning, if I reduced my calorie intake by 80 kcal per day, I'd become skeletal in two years and vanish in a puff of smoke within 10 years*.  All from a meager 3 percent reduction in calorie intake! 
 
What's wrong here?
Read more »

Wednesday, February 5, 2014

NutriScience Seminar in Lisbon with Lindeberg, Fontes, and Bastos

My friend Pedro Bastos has asked me to spread the word about a seminar he's organizing in Lisbon titled "Evidence and Evolution-based Nutrition".  It will include Staffan Lindeberg, Maelan Fontes, and Pedro Bastos-- three quality researchers in the area of evolutionary health-- I'm sure it will be interesting.  Here's the flier:
 
 

Sunday, January 12, 2014

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!


Wednesday, January 1, 2014

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).

Monday, December 30, 2013

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 (23).  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.

Read more »

Friday, December 20, 2013

Tuesday, December 10, 2013

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 (1234).  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?

Read more »

Saturday, November 23, 2013

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

Read more »

Monday, November 11, 2013

Recent and Upcoming Appearances

Smarter Science of Slim

Jonathan Bailor recently released an interview we did a few months ago on the neurobiology of body fat regulation, and the implications for fat loss.  It's a good overview of the regulation of food intake and body fatness by the brain.  You can listen to it here.

Super Human Radio

Carl Lanore interviewed me about my lab's work on hypothalamic inflammation and obesity.  I'm currently wrapping up a postdoctoral fellowship with Dr. Michael Schwartz at the University of Washington, and the interview touches on our recent review paper "Hypothalamic Inflammation: Marker or Mechanism of Obesity Pathogenesis?"  Dan Pardi and I are frequent guests on Carl's show and I'm always impressed by how well Carl prepares prior to the interview.  You can listen to the interview here.

The Reality Check podcast

Pat Roach of the Reality Check podcast interviewed me about the scientific validity of the "carbohydrate-insulin hypothesis" of obesity.  The Reality Check podcast "explores a wide range of controversies and curiosities using science and critical thinking", and a dash of humor.  This one should be very informative for people who aren't sure what to believe and want a deeper perspective on the science of insulin and body weight regulation.  You can listen to it here.

Obesity Society conference

Next Thursday 11/9, I'll be speaking at the 2013 Obesity Society conference in Atlanta.  My talk is titled "The Glial Response to Obesity is Reversible", and it will be about my work on the reversibility of obesity-associated hypothalamic neuropathology in mice.  My talk will be part of the session "Neuronal Control of Satiety" between 3:00 and 4:30, specific time pending.  See you there!

Monday, November 4, 2013

Buckwheat Crepes Revisited

One of my most popular posts of all time was a recipe I published in 2010 for sourdough buckwheat crepes (1).  I developed this recipe to provide an easy, nutritious, and gluten-free alternative to flour-based crepes.  It requires no equipment besides a blender.  It's totally different from the traditional buckwheat crepes that are eaten in Brittany, in part because it's not really a crepe (I don't know what else to call it, maybe a savory pancake?).  I find these very satisfying, and they're incredibly easy to make.  They're especially delicious with fresh goat cheese, or scrambled eggs with vegetables, but they go with almost anything.  Chris Kresser also developed his own version of the recipe, which is fluffier than mine, and more like a traditional pancake (2).

Buckwheat is an exceptionally nutritious pseudograin that's rich in complete protein and minerals.  In contrast to most whole grains, which have low mineral availability due to phytic acid, buckwheat contains a high level of the phytic acid-degrading enzyme phytase.  This makes buckwheat an excellent source of easily absorbed minerals, as long as you prepare it correctly!  Phytase enzyme works best in an acidic environment, which may be part of the reason why so many cultures use sour fermentation to prepare grain foods.  My original recipe included a sour fermentation step.

But there's a problem here.  Buckwheat doesn't ferment very well.  Whether it's because it doesn't contain the right carbohydrates, or the right bacteria, I don't know, but it spoils rapidly if you ferment it more than a little bit (using a strong sourdough starter helps though).  Others have told me the same.  So here's my confession: I stopped fermenting my buckwheat batter about a year ago.  And it tastes better.

Read more »

Tuesday, October 29, 2013

New Post on Eat Move Sleep Blog

Yesterday, the Dan's Plan blog Eat Move Sleep published a blog post I wrote about sleep, artificial light, your brain, and a free computer program called f.lux that can help us live healthier lives.  Head over to Eat Move Sleep to read it.

Wednesday, October 9, 2013

Sleep and Genetic Obesity Risk

Evidence is steadily accumulating that insufficient sleep increases the risk of obesity and undermines fat loss efforts.  Short sleep duration is one of the most significant risk factors for obesity (1), and several potential mechanisms have been identified, including increased hunger, increased interest in calorie-dense highly palatable food, reduced drive to exercise, and alterations in hormones that influence appetite and body fatness.  Dan Pardi presented his research at AHS13 showing that sleep restriction reduces willpower to make healthy choices about food.

We also know that genetics has an outsized influence on obesity risk, accounting for about 70 percent of the variability in body fatness between people in affluent nations (2).  I have argued that "fat genes" don't directly lead to obesity, but they do determine who is susceptible to a fattening environment and who isn't (3).  I recently revisited a 2010 paper published in the journal Sleep by University of Washington researchers that supports this idea (4).

Read more »

Monday, September 23, 2013

Speaking in Lisbon on October 5

My friend Pedro Bastos graciously invited me to speak at a conference he organized in Lisbon on October 5 titled "Food, Nutrition and the Prevention of Chronic Diseases".  I will give two talks:

  • "Ancestral Health: What is Our Human Potential?"  This talk will explore the health of non-industrial cultures in an effort to understand how much of our modern chronic disease burden is preventable, and it will briefly touch on one major aspect of non-industrial life that may protect against the "diseases of civilization".  This presentation will focus on age-adjusted data from high quality studies.  
  • "Why Do We Overeat: a Neurobiological Perspective."  This talk will attempt to explain why most of us consume more calories than we need to maintain weight-- a phenomenon that is a central cause of morbidity and mortality in the modern world.  It will touch on some of the brain mechanisms involved in ingestive behavior, and outline a framework to explain why these mechanisms are often maladaptive in today's environment.
Pedro will speak about dairy consumption, vitamin D, and chronic disease.  

The conference is targeted to health professionals and students of nutrition, however it's open to anyone who is interested in these topics.  It's sponsored by NutriScience, a Portuguese nutrition education and consulting company.  Sadly, I don't speak Portuguese, so my talks will be in English.  

Access the full program, and register for the conference, using the links below:

Monday, September 2, 2013

Is Refined Carbohydrate Addictive?

[Note: in previous versions, I mixed up "LGI" and "HGI" terms in a couple of spots.  These are now corrected.  Thanks to readers for pointing them out.]

Recently, a new study was published that triggered an avalanche of media reports suggesting that refined carbohydrate may be addictive:

Refined Carbs May Trigger Food Addiction
Refined Carbs May Trigger Food Addictions
Can You be Addicted to Carbs?
etc.

This makes for attention-grabbing headlines, but in fact the study had virtually nothing to do with food addiction.  The study made no attempt to measure addictive behavior related to refined carbohydrate or any other food, nor did it aim to do so.

So what did the study actually find, why is it being extrapolated to food addiction, and is this a reasonable extrapolation?  Answering these questions dredges up a number of interesting scientific points, some of which undermine popular notions of what determines eating behavior.

Read more »

Monday, August 26, 2013

More Thoughts on Cold Training: Biology Chimes In

Now that the concept of cold training for cold adaptation and fat loss has received scientific support, I've been thinking more about how to apply it.  A number of people have been practicing cold training for a long time, using various methods, most of which haven't been scientifically validated.  That doesn't mean the methods don't work (some of them probably do), but I don't know how far we can generalize individual results prior to seeing controlled studies.

The studies that were published two weeks ago used prolonged, mild cold exposure (60-63 F air) to achieve cold adaptation and fat loss (12).  We still don't know whether or not we would see the same outcome from short, intense cold exposure such as a cold shower or brief cold water plunge.  Also, the fat loss that occurred was modest (5%), and the subjects started off lean rather than overweight.  Normally, overweight people lose more fat than lean people given the same fat loss intervention, but this possibility remains untested.  So the current research leaves a lot of stones unturned, some of which are directly relevant to popular cold training concepts.

In my last post on brown fat, I mentioned that we already know a lot about how brown fat activity is regulated, and I touched briefly on a few key points.  As is often the case, understanding the underlying biology provides clues that may help us train more effectively.  Let's see what the biology has to say.

Biology of Temperature Regulation

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Tuesday, August 20, 2013

Reflections on the 2013 Ancestral Health Symposium

I just returned from the 2013 Ancestral Health Symposium in Atlanta.  Despite a few challenges with the audio/visual setup, I think it went well.

I arrived on Thursday evening, and so I missed a few talks that would have been interesting to attend, by Mel Konner, Nassim Taleb, Gad Saad, and Hamilton Stapell.  Dr. Konner is one of the progenitors of the modern Paleo movement.  Dr. Saad does interesting work on consummatory behavior, reward, and its possible evolutionary basis.  Dr. Stapell is a historian with an interest in the modern Paleo movement.  He got some heat for suggesting that the movement is unlikely to go truly mainstream, which I agree with.  I had the opportunity to spend quite a bit of time with him and found him to be an interesting person.

On Friday, Chris Kresser gave a nice talk about the potential hidden costs of eradicating our intestinal parasites and inadvertently altering our gut flora.  Unfortunately it was concurrent with Chris Masterjohn so I'll have to watch his talk on fat-soluble vitamins when it's posted.  I spent most of the rest of the day practicing my talk.

On Saturday morning, I gave my talk "Insulin and Obesity: Reconciling Conflicting Evidence".  I think it went well, and the feedback overall was very positive, both on the content and the delivery.  The conference is fairly low-carb-centric and I know some people disagree with my perspective on insulin, and that's OK.   The-question-and-answer session after the talk was also productive, with some comments/questions from Andreas Eenfeldt and others.  With the completion of this talk, I've addressed the topic to my satisfaction and I don't expect to spend much more time on it unless important new data emerge.  The talk will be freely available online at some point, and I expect it to become a valuable resource for people who want to learn more about the relationship between insulin and obesity.  It should be accessible to anyone with a little bit of background in the subject, but it will also be informative to most researchers.

After my talk, I attended several other good presentations.  Dan Pardi gave a nice talk on the importance of sleep and the circadian rhythm, how it works, how the modern world disrupts it, and how to fix it.  The relationship between sleep and health is a very hot area of research right now, it fits seamlessly with the evolutionary perspective, and Pardi showed off his high level of expertise in the subject.  He included the results of an interesting sleep study he conducted as part of his doctoral work at Stanford, showing that sleep restriction makes us more likely to choose foods we perceive as unhealthy.

Sleep and the circadian rhythm was a recurrent theme at AHS13.  A lot of interesting research is emerging on sleep, body weight, and health, and the ancestral community has been quick to embrace this research and integrate it into the ancestral health template.  I think it's a big piece of the puzzle.

Jeff Rothschild gave a nice summary of the research on time-restricted feeding, body weight and health in animal models and humans.  Research in this area is expanding and the results are pretty interesting, suggesting that when you restrict a rodent's feeding window to the time of day when it would naturally consume food (rather than giving constant access during both day and night), it becomes more resistant to obesity even when exposed to a fattening diet.  Rothschild tied this concept together with circadian regulation in a compelling way.  Since food is one of the stimuli that sets the circadian clock, Rothschild proposes to eat when the sun is up, and not when it's down, synchronizing eating behavior with the natural seasonal light rhythm.  I think it's a great idea, although it wouldn't be practical for me to implement it currently.  Maybe someday if I have a more flexible schedule.  Rothschild is about to publish a review paper on this topic as part of his master's degree training, so keep your eyes peeled.

Kevin Boyd gave a very compelling talk about malocclusion (underdeveloped jaws and crowded teeth) and breathing problems, particularly those occurring during sleep.  Malocclusion is a modern epidemic with major health implications, as Dr. Boyd showed by his analysis of ancient vs. modern skulls.  The differences in palate development between our recent ancestors (less than 200 years ago) and modern humans are consistent and striking, as Weston Price also noted a century ago.  Dr. Boyd believes that changing infant feeding practices (primarily the replacement of breast feeding with bottle feeding) is the main responsible factor, due to the different mechanical stimulation it provides, and he's proposing to test that hypothesis using the tools of modern research.  He's presented his research at prestigious organizations and in high-impact scientific journals, so I think this idea may really be gaining traction.  Very exciting.

I was honored when Dr. Boyd told me that my 9-part series on malocclusion is what got him interested in this problem (1, 2, 3, 4, 5, 6, 7, 8, 9).  His research has of course taken it further than I did, and as a dentist his understanding of malocclusion is deeper than mine.  He's a middle-aged man who is going back to school to do this research, and his enthusiasm is palpable.  Robert Corruccini, a quality anthropology researcher and notable proponent of the idea that malocclusion is a "disease of civilization" and not purely inherited, is one of his advisers.

There were a number of excellent talks, and others that didn't meet my standards for information quality.  Overall, an interesting conference with seemingly less drama than in previous years.

Tuesday, August 13, 2013

AHS Talk This Saturday

For those who are attending the Ancestral Health Symposium this year, my talk will be at 9:00 AM on Saturday.  The title is "Insulin and Obesity: Reconciling Conflicting Evidence", and it will focus on the following two questions:
  1. Does elevated insulin cause obesity; does obesity cause elevated insulin; or both?
  2. Is there a unifying hypothesis that's able to explain all of the seemingly conflicting evidence cited by each side of the debate?
I'll approach the matter in true scientific fashion: stating hypotheses, making rational predictions based on those hypotheses, and seeing how well the evidence matches the predictions.  I'll explore the evidence in a way that has never been done before (to my knowledge), even on this blog.

Why am I giving this talk?  Two reasons.  First, it's an important question that has implications for the prevention and treatment of obesity, and it has received a lot of interest in the ancestral health community and to some extent among obesity researchers.  Second, I study the mechanisms of obesity professionally, I'm wrapping up a postdoc in a lab that has focused on the role of insulin in body fatness (lab of Dr. Michael W. Schwartz), and I've thought about this question a lot over the years-- so I'm in a good position to speak about it.

The talk will be accessible and informative to almost all knowledge levels, including researchers, physicians, and anyone who knows a little bit about insulin.  I'll cover most of the basics as we go.  I guarantee you'll learn something, whatever your knowledge level.