Thursday, April 28, 2011

Food Reward: a Dominant Factor in Obesity, Part I

A Curious Finding

It all started with one little sentence buried in a paper about obese rats. I was reading about how rats become obese when they're given chocolate Ensure, the "meal replacement drink", when I came across this:
...neither [obesity-prone] nor [obesity-resistant] rats will overeat on either vanilla- or strawberry-flavored Ensure.
The only meaningful difference between chocolate, vanilla and strawberry Ensure is the flavor, yet rats eating the chocolate variety overate, rapidly gained fat and became metabolically ill, while rats eating the other flavors didn't (1). Furthermore, the study suggested that the food's flavor determined, in part, what amount of fatness the rats' bodies "defended."

As I explained in previous posts, the human (and rodent) brain regulates the amount of fat the body carries, in a manner similar to how the brain regulates blood pressure, body temperature, blood oxygenation and blood pH (2). That fact, in addition to several other lines of evidence, suggests that obesity probably results from a change in this regulatory system. I refer to the amount of body fat that the brain defends as the "body fat setpoint", however it's clear that the setpoint is dependent on diet and lifestyle factors. The implication of this paper that I could not escape is that a food's flavor influences body fatness and probably the body fat setpoint.

An Introduction to Food Reward

The brain contains a sophisticated system that assigns a value judgment to everything we experience, integrating a vast amount of information into a one-dimensional rating system that labels things from awesome to terrible. This is the system that decides whether we should seek out a particular experience, or avoid it. For example, if you burn yourself each time you touch the burner on your stove, your brain will label that action as bad and it will discourage you from touching it again. On the other hand, if you feel good every time you're cold and put on a sweater, your brain will encourage that behavior. In the psychology literature, this phenomenon is called "reward," and it's critical to survival.

The brain assigns reward to, and seeks out, experiences that it perceives as positive, and discourages behaviors that it views as threatening. Drugs of abuse plug directly into reward pathways, bypassing the external routes that would typically trigger reward. Although this system has been studied most in the context of drug addiction, it evolved to deal with natural environmental stimuli, not drugs.

As food is one of the most important elements of survival, the brain's reward system is highly attuned to food's rewarding properties. The brain uses input from smell, taste, touch, social cues, and numerous signals from the digestive tract* to assign a reward value to foods. Experiments in rats and humans have outlined some of the qualities of food that are inherently rewarding:
  • Fat
  • Starch
  • Sugar
  • Salt
  • Meatiness (glutamate)
  • The absence of bitterness
  • Certain textures (e.g., soft or liquid calories, crunchy foods)
  • Certain aromas (e.g., esters found in many fruits)
  • Calorie density ("heavy" food)
We are generally born liking the qualities listed above, and aromas and flavors that are associated with these qualities become rewarding over time. For example, beer tastes terrible the first time you drink it because it's bitter, but after you drink it a few times and your brain catches wind that there are calories and a drug in there, it often begins tasting good. The same applies to many vegetables. Children are generally not fond of vegetables, but if you serve them spinach smothered in butter enough times, they'll learn to like it by the time they're adults.

The human brain evolved to deal with a certain range of rewarding experiences. It didn't evolve to constructively manage strong drugs of abuse such as heroin and crack cocaine, which overstimulate reward pathways, leading to the pathological drug seeking behaviors that characterize addiction. These drugs are "superstimuli" that exceed our reward system's normal operating parameters. Over the next few posts, I'll try to convince you that in a similar manner, industrially processed food, which has been professionally crafted to maximize its rewarding properties, is a superstimulus that exceeds the brain's normal operating parameters, leading to an increase in body fatness and other negative consequences.

* Nerves measure stomach distension. A number of of gut-derived paracrine and endocrine signals, including CCK, PYY, ghrelin, GLP-1 and many others potentially participate in food reward sensing, some by acting directly on the brain via the circulation, and others by signaling indirectly via the vagus nerve. More on this later.


Might-o'chondri-AL said...
This comment has been removed by the author.
Poisonguy said...

Bit surprised you didn't pick up on this earlier given that Lustig seemingly mentions this in every paper and speech he publishes/makes.

gunther gatherer said...

This post is excellent Stephan, it's a whole new world of thought about obesity.

Paleo Flavours seem to be what we should be keeping to. Today's processed foods are overwhelming our hunter gatherer brains.

Come to think of it, maybe this is why Atkins diet products, protein bars and other flavoured nutritional supplements should be avoided. When I was on Atkins years ago (not paleo) I initially lost weight, but then found myself eating like a pig all the time. I was drinking Atkins shakes every day. Guess what flavour they were!

The high rate of failure on diet programs such as Atkins and Weight Watchers and any other brand that makes it's own faux desserts and candy bars could be due to this simple fact. Trying to tailor an ancestral diet to taste neolithicand modern might be doing more harm than good.

David Moss said...

Wow, I'm so glad that you've posted this. I thought, back when you posted about the 'potato diet' that palatability was a pretty neat explanation and thought that your explaining it under the aegis of a 'bodyfat setpoint' was a bit confusing. Now it's clear from what you've written that other factors, like palatability are causally prior to the 'setpoint.'
I think palatability is probably the major lacunae of the paleo movement at the moment and probably a major factor for fat loss. (Similarly stomach distension: the paleo community seems to have ignored physical fullness somewhat, in their haste to distance themselves from low fat/high fibre.

This is certainly true to my experience, in any case, I lost a striking amount of weight (and I wasn't overweight to begin with) when I started eating decidedly unpalatable ground dessicated coconut for most of my calories.

gunther gatherer said...

And extending the idea of reward chemicals which cause certain behaviours, I think we can also include cow's milk, whose casein is full of opiods which have been known to stick to receptors on the human brain.

Epidemiological studies show that the highest CVD and diabetes takes place in high milk-drinking countries. Leaving the lactose issue aside, I would think the casein in the milk would encourage hyperphagia, which raises insulin too often and too much, which leads to many diseases of civilisation.

Colldén said...

Matt Stone was into this as well a while ago, so I'll pose the same question I asked him, even though I'm not exactly sure where you're going with this yet. But, if the pleasurability of food (ie intensity of reward) can upregulate body fat set point, how come the european societies (France and Italy) who are widely considered to put the highest premium on tasty food, where there is a strong cultural imperative that eating should be a delight - how come they actually have some of the lowest obesity rates in the western world?

Anya said...


have you read the findings of Todd Becker from gettingstronger ?

He has come to similar conclusions and tries to consolidate a lot of this in his diet recommendations :
dubbed the The Deconditioning Diet.

Careful, long and complex read ahead.

gunther gatherer said...

Sorry, I meant "Epidemiological studies show that the highest CVD and diabetes takes place in high COW milk-drinking countries". Goat and sheep milk drinking countries don't get anywhere near the obesity, diabetes and CVD that we do.

Sure, this could be due to many lifestyle factors, but it's significant enough to give it some thought. Food opiate elimination should be a large part of the dietary regimes of those trying to lower appetite and lose weight.

Jenny said...

I wouldn't leap to the conclusion that this study can be trusted. Animals have such a strong lust for vanilla that it is used to trap them in the wild. My cat, a very finicky eater who wouldn't eat most cat food, several times chewed through the wrappings on packages of vanilla wafers and gobbled them up.

So this result sounds to me like one that would claim that cats prefer toothpaste to catnip.

Also, the amount of actual chocolate in Ensure is quite small.

Poisonguy said...

gunther gatherer, there's some epidemiological studies in Sweden that show the highest prevalence of CVD and diabetes take place in high taxation counties. I like what you say, so don't take it personally. I'm just not a big fan of correlations. Strike that. I not a fan at all.

Brock said...


Stephan said "industrially processed food, which has been professionally crafted to maximize its rewarding properties, is a superstimulus".

My answer (Not Stephan's) - He didn't say "French cuisine made from scratch using traditional methods." There's a world of difference between whole grain oatmeal with milk and honey vs. Fruit Loops.

Charlie said...

RE: France and Italy.

The most common comment I hear from Europeans is that Americans eat like children. They like soft, gooey, sweet food. France and Italy have plenty of adult flavors, which although they can be appreciated, are very different that the ones Stephan elucidated. Wine vs. grape juice -- or wine vs. the imported Australian plonk.

Two local sayings:

Eat until you are 80% full.

Eat hard things to make you hard.

Jeff Borsato said...

this is akin to Seth Robert's "shangri-la" dietary approach, surprised no one has mentioned this.

basically retraining the brain to accept flavorless calories and break the reward pathways to reduce intake (in the form of light olive oil or something similar at night, with a plugged nose)

interesting ideas, not clear if they have been broadly studied.

Colldén said...

What is the difference Brock? Fresh home cooked foods (done right) are certainly tastier than industrially processed foods, it stands to reason they stimulate our reward centers more too.

It's not even the point that home cooked foods can be more centrally rewarding than industrially processed foods, its that the western societies with the strongest traditional emphasis on tasty food actually have the least problems with obesity. If highly rewarding processed food upregulates the fat set point, why doesn't the same principle apply to more vs less tasty whole foods?

Charlie, I don't know about "gooey", but both the french and italians sure do eat a lot of sweets.

Charlie said...

@Colldén; yes, sweets.

But think of the difference between gooey chocolate chip cookies, brownies, and apple pie vs. creme brulees, butter cookies and tart tartin. very different mouthfeel.

I'm not blown away with the obesity numbers of americans vs. europeans. Factor in smoking, race, education and poverty, and US numbers aren't dramatically different. Overweight numbers seem to be about the same as well - around a quarter of the adult population.

And let's be clear, there are a lot of new world deserts available in both france and italy! tiramsu, for example, is pretty "gooey" and "childish".

Gazelle said...

I've always suspected that the difference between obese Americans and slim Europeans who both eat sweets are that the Americans have blown out their dopamine receptors and need to eat much more to get the same reward effect...

David Csonka said...

This should be interesting, thanks Stephan!

gallier2 said...

Just a idea, because I'm not entirely sold on the this "new" idea. charlie's point about France and Italy is salient.
What I suppose, is that these reward centers do not like to be cheated. Give them fake food they "thought" were nutritious and they will continue to ask for more.
May be the chocolate rats had a prior training on something similar that was good nutrition (the fat may be).
My idea is that it's the emptyness of the calories that are partly to blame or that it's a factor in the problem.

Jeffrey of Troy said...

I've started noticing "natural flavors" on the list of ingredients of many food products, even seemingly "healthy alternatives". I wondered:

1.) What is in the food that they feel a need to add "flavors"?

2.) What would it taste like w/o added "flavors"?

3.)When I make food at home, I don't add "flavors" as a separate ingredient...

Jeffrey of Troy said...

Also, re: obesity epidemic

I recently became aware that over 2000 nuclear bombs have been exploded all over the earth so far, every one introducing radioactive particles into our environment.

(Add to this Chernobyl.)

The U.S. gov may have realized that the particles are stored in the fat of animals, so started saying, "avoid fat!" Then they had to come up w/ a justification, hence all the bs about "artery-clogging animal fat".

Unfortunately, that left us eating a high-grain/low fat diet (and replacing animal fat w/ seed oils), which we know now makes most people fat (and being fat makes them sick via inflammatory cytokines).

Bottom line: supporting the body's natural detoxification pathways may be an essential component of reversing the obesity epidemic.

antispirit said...

I recently ate some sort of sweet chippy thing that someone bought from the store. Apple Straws, I think? I had one and didn't like it. It tasted like "sweet" and "apple". That was it. Maybe it's not the intensity of the "reward" in industrially processed foods. Maybe it's the utter lack of other flavors to give the "sweet" or "apple" a context. There's no such thing as just "sweet" in nature.

antispirit said...

Then again, Seth Roberts was able to get great results with sugar water... so what do I know?

Robert said...

" tastes terrible the first time you drink it because it's bitter..."

I've often wondered about this. Take out the 'reward' aspect from drinking beer, wine, spirits etc and what are you left with?

I suppose this just goes to show the powerful effect the brain's reward mechanism has on us.

Malibu said...

ahhhh i am going to love this series. I full blown am convinced after spending a little over a year studying the brain(I know I’m still a rookie), that obesity/starvation is the result of a dysfunctional hypothalamus. On one side you have dopamine problems and the other serotonin problems which both are resulting from how your hypothalamus handles stress(including food).

Worth mentioning is thirst. There is extra and intracellular thirst, one results from salty food(or food intake) and the other is the result of fluid around your cells. if you give someone a pill that keeps their tongue wet they will still drink. Ensure is a salty sweet personally I think disgusting drink(having had it before, it is the MOST popular drink, chocolate, in anorexia treatment centers…coincidence?) and I have always disliked chocolate.

It seems most-to-everything(food/thirst) besides a drive for sex and an avoidance of pain are all for the MOST part externally conditioned.

Evolutionarily speaking, it only makes perfect sense for people to have an inborn desire to eat rewarding food when rewarding food is available. Thats why 'grok' ate an entire banana tree if he ever came across one. I think 99% of our evolution has been one big yo-yo diet(feast on fruit & famine until you find a deer to kill) until recently, where food is provided in abundance and unnourishing (though your brain thinks it should be coming with all this attached nutrition) junk is at our disposal.

Every time someone eats something 'industrial', the brain levels of neurochemicals such as neuropeptide Y (NPY), pro-opiomelanocortin (POMC), corticotrophin releasing hormone (CRH) and a bunch of others all go up or down and out of balance, most likely as a result of altered leptin. From there, the brain responds to the various changes to determine how much (or how hard) to affect things like metabolism, body temperature, liver fatness, heart rate etc. To harp on the health industry, I do think they are catering to what they think they can handle. Being humans, we take advice to the extreme. Just look at everyone on the vitamin D and Omega 3 bandwagon. We get wind of vitamin D being healthy…so what do we do….go buy supplements with most likely oxidized oil in them b/c God forbid we go outside in the sun and break a sweat. Same with Omega 3….throw back some pills instead of flipping eating some fish. Given just that, the AHA or USDA gives advice which people are going to misinterpret. If you go out saying saturated fat is healthy…everyone will start gorging chili cheese burgers and deep frying all their food in tallow. Its not fat is ‘ok’ now fat is what they all want, on top of what they eat. Saturated fat healthy, hell line up for fresh donuts at krispy kreme. Tell someone chicken is good and they line up at KFC they surely don’t go buy chicken to cook themselves. Tell someone saturated fat is good and the open their pocket knife at the fridge and eat a 16oz block of cheese or take cheez whiz to the mouth. Yes, this makes people look ‘stupid’ as the USDA would if they made such statements. I think it comes down to what information is worth letting out vs its consequences. People aren’t willing to give up ‘x, y and z’ for the rest of their lives especially if it is available 24/7 so telling they ‘a b and c’ are healthy is barking up the wrong tree. Go to 99% of diabetics. Their doctors give them pills because they know, really they aren’t that stupid, how humans are. They aren’t willing to change their diet, so give them pills allowing them to be happy but unhealthy. Happiness wins out everytime, always.

Malibu said...

I have a feeling this is why leptin injected into an obese does nothing(their hypothalamus is already f*cked), but leptin injected into someone who has gone from 300 to 150lbs will restore all hormonal/chemical pathways in the brain. Short-term signals like ghrelin, peptide YY, glucose all interact at the hypothalamus.

Not surprising, as people gain weight, their caloric requirements go up- and to link to the brain, the first time you bite a chocolate bar its good, then it takes more and more to get that 'hit' off chocolate until you’re going through a Halloween bag of candy to feel ‘good’. Brain needs more 'calories' to get the buzz thus your desire to keep eating chocolate.

and there’s always the psychology part. you tell yourself you’re on a diet. you get restriction mentality. you always want what you cant have- again, human instinct. No other animal besides us eat food for reasons totally unrelated to actual physiological needs(like seeing burger king on TV and wanting it, or craving popcorn when you watch a movie, a lb of chocolate when you have a bad day etc). The psychology is ultimately as important as the physiology in understanding obesity as well as starvation.

In obesity, once the hypothalamus is f*cked, ultimately a ketongenic diet will be preferable simply because it does somewhat of a job of satisfying appetite in a person who has no hunger/fullness cues not to mention repairing the insulin resistance in the body.

Ok, I have drawn this long enough….sorry for the excess but I love the topic!!

Mirrorball said...

I expect all of you have already read The End of Overeating, by David Kessler, which is exactly about how "hyperpalatable" industrial foods make us overeat.

Matt Lentzner said...

I have come to think of processed food as a sort of edible pornography - that is, something that stimulates the basest desires of our reward system. Just with food instead of sex.

Galina L. said...

Well, I am not from France, I am from Russia, moved to US at 1999, and can testify that American food is grossly over-flavored. People here find raw almonds and walnuts too bland, cakes and cookies are so sweet, it made my throat burn when I tried to eat it. If something contains cinnamon - beware - it is almost as spicy, as if instead of cinnamon black pepper was used. People in all countries are trying to make their food taste good,it not necessary led to the overuse of flavor. On another hand, Russian food is similar to German and Polish food. Not everybody is slim in those countries. Also, in India people may use more spices than in America. A complicated issue. What if it is a over-flavoring of foods consisted of refine carbs?

Aaron Blaisdell said...

Any rat behavioral researcher knows that rats absolutely LOVE chocolate! They like Froot Loops(tm), too, but chocolate is primo in practically innately palatable foods. Not sure why this is, but it's common wisdom in my field of study.

For years now, in my lectures on super normal stimuli (a term and concept invented by the ethologists, such as Niko Tinbergen, many decades ago), I discuss both junk food and breast implants as examples.

Might-o'chondri-AL said...
This comment has been removed by the author.
Stephan Guyenet said...

Hi Folks,

Great discussion. Regarding the palatability of the French diet vs. the American diet. Yes, the French eat well and are known for their good food. But keep in mind that the average French family doesn't eat at a 5 star restaurant every day. On most days, they eat simple, home cooked food. That is changing of course, as the food system industrializes, and obesity rates have also increased.

My feeling is that although they're related, there's not a 1:1 correspondence between "good food" and rewarding food. Good food is fresh, tasteful and varied, and appeals to our higher-order aesthetic and nutritional concepts. Industrially processed rewarding food appeals, as Matt L said, to our "basest desires"-- plugging directly into our hard-wired preferences and associating it with flavors that are strong and constant.

Seth Roberts calls it "ditto food"-- food that tastes the same every time, such as a McDonald's french fry. That allows the formation of very strong rewarding flavor-calorie associations. Food manufacturers know this, which is why they strive for extreme flavor consistency. No matter how good your home-cooed food is, it will never be the same ever time.

Helen said...

gunther gatherer - Hmmm. I was just looking up dairy and diabetes and found an inverse relationship between dairy consumption and Type 2 diabetes, in a dose-dependent fashion. I can't remember which country/ies these studies were done in, but they were dairy-eating, since it was more vs. less consumption in a given population.

What you say about dairy- vs. non-dairy-eating countries may be true, but it may be something other than the dairy causing the difference.

I have lost a lot of weight in the past year. At first I was low-carb, now I'm low-fat. I find both diets more than a little bit boring. I'm sure I do eat less than I used to.

I wondered that, too, about the Ensure flavors, Jenny. Vanilla is appealing, but maybe vanilla Ensure not so much.

Helen said...

Aaron and M-Al - Just read your comments about rat preferences re: chocolate vs. vanilla. Interesting!

M-Al & Jenny - cats are weird.

More on vanilla - I've heard that vanilla tastes like something in breast milk. People do love it, and this may be hard-wired, but it doesn't take long for most people to prefer chocolate. I've heard that part of this desire is driven by oxalate-loving bacteria in our gut.

vlprince said...

Heh- I did a rotation in a glucose-sensing/diabetes lab, and I remember walking into the animal room the first day and seeing 4 cases of chocolate ensure in the corner. It was definitely common knowledge that chocolate ensure was the ticket- not the other flavors!

Carl M. said...

One of the reasons that raw food diets cause people to lose weight is that raw foods -- especially varieties that haven't been overly altered from the wild -- elicit a taste change response after you have had enough. I did the experiment and dropped 30 pounds in somewhere between one and two months. (And this was a high fructose diet, as I ate a LOT of fruit.) Eventually I had to quit because nothing natural tasted good.

Heavily processed foods generate no taste change response. And some of the newer fruit varieties also produce no such response even when raw.

Jeremy said...

Hi Stephan... I've been expecting this post for a while now!. It's an intriguing idea, and I'll be very interested to see what you come up with. But so far, I'm unconvinced that palatability is a driving force behind obesity. Looking at the ensure study, it's certainly possible that the chocolate flavor caused the rats to overeat. But there's another possibility as well. Ensure is packed with sugar. It could equally well be the case that sugar causes obesity (for which there is already an enormous body of evidence), but that the unpalatability of strawberry or vanilla ensure prevents rats from overindulging -- or at least from eating large quantities at once, which would bring about the disastrous biochemical changes that lead to body fat dysregulation. As a result, palatability may be a factor in obesity, but not the cause. Unpalatable food -- like exercise, genetics, or various other factors -- can help protect people from obesity. But the cause may still just be sugar. The question is whether people can get fat to begin with on any ultra palatable food. Is all that matters the stimulation of the taste buds? Or do people have to physically ingest a specific nutrient in order to get fat? It's a big question, and I won't make any judgments until I've seen the next installments, of course!

gunther gatherer said...

Hi Helen, I think you should have a look on Google regarding "A1 and A2 beta casein" and "BCM7", which is the opiate that A1 milk produces in the human body. This is not taken into account in the epidemiological observations of most researchers.

A1 is the dominant beta casein we eat in the western world, due to a mutation that occurred about 2000 years ago. A2 (from goat, sheep, yak, buffalo, and certain Asian cow breeds) is the original casein we ate when we brought herds into Europe.

Here is Keith Woodford's website, where he discusses the topic. He wrote the book "Devil in the Milk", which was quite convincing for me. Yes I know correlation does not mean causation, but why wait for researchers to catch up while we all slowly get sick?

Greenacres said...

Isn't this theory pretty much the common wisdom of the last few generations?
I'm not criticizing; it's just that I would prefer a more exotic explanation that would encourage me to eat less kale and more brownies.
Fat Americans, like me, enjoy eating food that is rich and gooey and crunchy. So we eat too much. This sounds pretty hopeless for those of us who have been overindulging all these many years.

Helen said...

Hi gunther gatherer,

I've heard of the correlation between A1 milk and Type I diabetes, but not Type II. Since we're genetically at risk for Type I (as well as Type II, alas), I do buy local milk and yogurt from Jersey (A2) cows for my kids, even though I wasn't thoroughly convinced by the evidence I found online. (For instance, the Masai consume A1 milk, yet have little CVD and do not have an elevated incidence of Type I diabetes.)

I figure it doesn't hurt to hedge our bets by drinking A2 milk, just in case it makes a difference, and it comes in glass bottles that are reused by the dairy, which I also like.

We have so many other food issues in our family - dairy is something we all tolerate, so we eat it.

gunther gatherer said...

Hi Helen. The Maasai use exclusively A2 cattle and goats for their fermented milk. This is made special mention of by both Woodford and by Mark Sisson on his "Definitive Guide to Dairy" section of Mark's Daily Apple.

That said, the confounder there could be that the milk is always fermented for the Maasai and other milk-drinking cultures, which destroys the lactose before it can raise your insulin. That and the absence of other neolithic agents of disease, activity, lack of stress, etc. It's so hard to tell what's doing what and where!

Helen said...

Hi gunther -

I just Googled Masai/Maasai and A1 and A2 milk and the results so far agree with you, but I know I read that somewhere! If this is the case, that makes me more glad we're using the A2.

arnoud said...

Most interesting post!
Reading Might-o'chondri-AL's first comment to this post left me thinking there may be a combination of factors:

- the brain's Food Reward system, creates powerful incentives to eat more of the foods we enjoy most (favor, texture, as well as other pleasurable effects on the body and/or brain) As mentioned many triggers of the 'Food Reward' are fleeting, creating an urge to continue consumption.

- the brain's 'fulness' feedback system creates incentives to stop eating as we feel 'satisfied' with foods already consumed

The combination of these two processes could help in understanding how foods manufactured to be high in 'Food Reward' AND low in 'fulness satisfaction' could affect obesity. My guess is that the Food Reward factor is more powerful than the 'fulness' factor

Traditional 'whole' food based meals have these two factors in good balance.

A somewhat related thought:
many restaurants serve breads (and drinks) almost immediately after customers are seated. Could the quick Food Reward of the bread (and the drink), arriving in an empty stomach, be incentivizing the brain to order bigger meals? I have no doubt that this is the case.

Might-o'chondri-AL said...
This comment has been removed by the author.
Tom said...

A fine point: Beer is not bitter unless it was brewed with a lot of hops (the current style embraced by most American breweries, and which I find quite distasteful). Traditional European lagers, pilsners, and to a lesser extent ales are not bitter. I think one reason that a mild light lager might not taste good to a person who had never had beer is that Americans are used to only drinking highly sweetened beverages. Most people I know do not like unsweetened tea or coffee, both of which are more bitter or astringent than beer.

Then there is the issue of small beer, lambic ales, and the like which have less alcohol and more nutrition and I've read are closer to the fermented beverages our ancestors drank.

WilliamS said...

Might-o'chondri-AL wrote...

"The article also discussed BCM-7; which in vitro influences immune cells. However (citing a 1997 study)there was no agreement that BCM-7 is actually released in vivo; I don't know if there is a more recent proof that BCM-7 is bio-active, however."

See this:

R. K. said...

I also wonder if there is an overlap between your analysis and the analysis explored in The End of Overeating, by David Kessler. I was impressed by the experiments he referenced in that book (less so by his recommendations).

I know that trying to imagine the Paleo lifestyle is a big white canvas and most portraits are probably off and thus it's probably not of much use to speculate. And yet, I cannot help but speculate. I doubt that a typical pre-10,000 years ago Paleo supper came anything close to the one I fixed for my family tonight: burgers and mushrooms fried in butter and bacon fat, squash sauteed in butter, baked potato with sour cream and salt and pepper, and parsnips and carrots baked in butter. That meal fits within most Paleo diet guidelines. And yet, when I look at a paper such as the one by Dr. Cassidy which compared the eating habits of Indian Knoll vs. Hardin Village, I suspect the typical Indian Knoll meal had a different flavor profile. I can imagine the following conversation:

"What's for dinner?"
"Snails and mussels."
"Again? Snails and mussels? Again? I was hoping for a Ribeye Steak covered in a Diane cream sauce, with baby carrots sauteed in pastured butter on the side."
"The dogs will be happy to eat your portion."
"Don't you have anything else?"
"You can nibble on the herbs I foraged. At least, I think they're herbs. Hopefully they're not too bitter and not too poisonous."

CarbSane said...

In addition to what I like to call engineered palatability, it seems our tastebuds become desensitized to sweet and salt over time. This might play a role in overeating to get one's "fix".

Gallier also makes a good point with: Give them fake food they "thought" were nutritious and they will continue to ask for more.

I'd be willing to bet that the obesity epidemic correlates well with increased use of artificial sweeteners. Not saying AS consumption causes obesity, but in terms of homeostasis, if our brain thinks we're getting sugar calories but we're not, it could very well be messing with our homeostasis.

WilliamS said...

Might-o'chondri-AL said...


Might, see here:

A Wealth of Health said...

Hi Stephen, a quick question for you... I'm just wondering if you've ever looked at Matt Stone's website 180 degree health. As a frustrated post Paleo, currently Weston Price inspired eater, some of what he has to say seems inspiring. My problem with him is he has a theory with the body fat set point, that seems unvalidated. Just wondering if you have any thoughts on his HED (high everything diet) plan. Thanks for your input (even if you don't have a response to my post), You seem to be the only voice of logic and reason in the sea of whole nutrition. I think you should write a book!

A Wealth of Health said...


Razwell said...

Dear Stephan

I wanted to say I link to you often at my blog, and hope you find the material useful. I genuinely respect you because you're a real scientist who studies this subject in detail.

*Genuine science always admits uncertainty and vast unknowns.

You do too :)

Scientists currently do not understand the chemical behavior of fat cell receptors. (They know some things that can disrupt them, however) Having a complete understanding of this is one of the essential things we need to understand to solve obesity.

The unknowns about obesity are far greater than the knowns. I sincerely hope the links on my blog can give you ideas Stephan , as they would be more use to you.

There are many. I'm pretty sure you'll be intersted . ;)

Take care,


Might-o'chondri-AL said...
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Richard said...

I am thinking about all this, including some of the comments. I am a big fan of the Archevore Blog, and it seems to me that it is easy enough to avoid obesity, simply by avoiding certain foods. Avoid wheat in any form, minimize other grains, eat no sugar and no PUFA, and eat mainly at lunch and dinner. Eat some liver every week, and eggs.

If you want to eat a "modern" diet, be prepared for modern consequences.

On the flip side, my personal view is that if you eat the proper diet (by excluding the things that are not good for you) you can, in an emergency, or as socially convenient, eat whatever you want, if necessary. What modern man has plainly done is convert the ability of the human animal to eat almost anything (wheat, PUFA, and fruit) in an emergency, into using those food substitutes as the staple of the modern diet. Not good.

What I fail to see is the need to "defend" the "traditional" or "Modern" diet. Why try to justify or maintain an activity or habit that clearly has negative consequences?

Alternatively, is there something horrible that will happen to you if do an experimental diet change and see what happens? Just try the first four steps of the Archevore "diet" and do it for a month, or two. Or three. The most likely consequence will a surprising weight loss. Without feelings of hunger. There is a big difference in the hunger sensations following a high-fat/protein meal as compared to a high carb meal.

There is no doubt that some parts of the modern diet are very tasty. I like a good cigar, too. I am not so sure that a cigar every now and then will kill me, but continual use, just as continual consumption of the modern diet, will certainly have adverse consequences.

As for the modern diets being too flavorful, how much better can it be that roast lamb or a good steak? Or a proper cheese?

Ms. Strathman said...

I'm very much enjoying this discussion. About a year ago, I started eating a high fat, low/moderate carb, moderate protein version of the paleo diet. At 5'9", I went from 160 to 140 lbs. in two months. Over the next eight months, the weight slowly returned. As much as I try to replicate my life at the time I lost the weight (including diet, exercise, sleep, stress), I cannot get back to that magical time.

I try to focus on all the other positive health benefits I've experienced from this way of eating, but I can't help being curious about why I lost the weight so quickly and effortlessly and why I can't duplicate the results.

JBG said...

Might-o'chondri-AL said...

"Journal "Diabetologia" (2002) contends no difference in pancreatic cytokine gene activity between A1 & A2 Beta casein; these were multiple country studies done on rats induced for Type 1 diabetes..."

See page 3 of:

Woodford calls the study a "scandal". The A2 material was contaminated with A1 material. The scientists knew it and published anyway.

BTW, I spent a little time looking for the actual article but could not find it. Have a reference?

Might-o'chondri-AL said...
This comment has been removed by the author.
Me said...

Looking forward to reading more about the stomach distention, vagus nerve, etc. Like this post.

JBG said...

Thanks, Might-y, for the citation. For others interested, here is the URL:
The article is way over my head so I haven't undertaken to read it, but it does seem clearly to be the one Woodford was talking about.

Like yourself, I have no expertise in this area, but if there are a number of studies on one side (Woodford says hundreds), and just one challenged one on the other (which vested interests trot out repeatedly), it's not too hard to decide where to place my bets.

Re the necrotizing entero-colitis matter (about which I know nothing), if it has anything to do with a1/a2,
note that Woodford says that ALL mammalian milk is a2 except that from a1 cows. For example, milk from Jersey or Guernsey cows is reliably a2, but not that from Holsteins, which produce most American commercial milk. Finding a wet nurse in modern America could be a challenge; locating some Jersey milk might be a little easier.

JBG said...

Correction -- Woodford doesn't claim "hundreds" of supporting papers, but rather "more than a hundred". Just keeping things on the up-and-up.

Here is one example to show that Jersey/Guernsey milk can be found:

Ned said...

For those wishing to consume dairy products, but not a1 milk, goat milk is becoming more available than it used to be.
I hesitate to recommend the goat milk typically available in supermarkets, as it is often ultra-pasterized, a process that some believe damages the milk.
However, searches on local foods sites, or perhaps Craigslist, may yield local sources for goat milk.
I bought several Lamancha goats, to have my own source. Perhaps that would be a bit extreme for most.

Jack C said...

Gunther Gatherer, Helen:

I believe it is type 1 diabetes that is increased by the BCM7 from A1 milk.

BCM7 will pass through a leaky gut but not a healthy gut. See page 216 of book.

Jack C said...

Gunther Gatherer, Helen,

A recent update by Keith Woodford largely verifies much of what he wrote regarding BCM7 in A1 milk.

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JEAN said...

To JBG, Milk Banks are common in American hospitals, I don't know how much neonatologists are using them, but mothers are.


This was just one of hundreds of hits on Google. For more information on mother's milk for all children, access the blog 'Cooling Inflammation', written by Dr. Art Ayres, he is a PhD in biochemistry, specializing in heparan research. He writes about inflammation in the body, with a focus on gut inflammation, rosacea, psoriasis, and other manifestations of body inflammation, but his wife is a lactation specialist. He has several interesting posts on the value of human milk in newborns.

williebr said...

With alcohol it was horrible at first, then fun to get drunk, then got a little older and got hangovers - now every time I smell alcohol I feel hung over and its all repulsive to me again.

Neat post.

Todd Hargrove said...

Here are some speculations.

If the body has a set point that is to some extent set by the reward value of certain foods, is it also possible that the brain has a changeable set point for getting a certain reward level from food or other external sources? In other words, is it possible that one person needs say "20 reward points" from external sources in a day, while another might need only 10. Perhaps this is the difference between a buddhist monk and a person with poor impulse control who is likely to gamble, overeat, and develop other addictions.

Perhaps junk food eating is less a cause of obesity than a marker for having high reward needs from exogenous sources. Maybe vegetarianism is the reverse.

I have noticed that when thin vegetarians sit down to a meal they don't have the look of someone who is about to get rewarded. Maybe they just don't need as much reward from food as others. If so, it would be very easy for them to eat the unpalatable food that gives a low weight set point.

If any of these speculations are correct, it would suggest that moving the weight set point down by eating less palatable food would fail unless it also reduced the reward set point. Perhaps this explains the emotional struggles that some people have with losing weight, and why people can tend to trade one addiction or another.

Matthew said...

This reminded me of a passage I recently read in the book Empires of Food by Evan Rimas and Andrew Fraser. It is a quote from Saint Bernard of Clairvaux, the founder of the Cistercian monastic order in France the twelfth century. He was criticising the lavish lifestyle of the Benedictine monasteries.

“Course after course is brought in. Only meat is lacking and to compensate for this two huge servings of fish are given. You might have thought that the first was sufficient, but even the recollection of it vanishes once you have set to on the second. The cooks prepare everything with such skill and cunning that the four or five dishes already consumed are no hindrance to what is to follow and the apatite is not checked by satiety... The selection of dishes is so exciting that the stomach does not realise that it is being over-taxed.”

Stephan Guyenet said...

Hi Todd,

Excellent observation. I do think different people have different reward thresholds. In rodents, one of the ways to increase your reward threshold is to become addicted to a drug of abuse, or eat lots of highly palatable food! There's evidence from brain scans (fMRI) in humans that the same may be true for us.

I also think that rewarding food, drugs, etc. are things that we use to help us cope with our stressful lifestyles. Rewarding things feel good, and rodents/people are driven to seek them more when they're stressed (up to a point). I notice that when I'm meditating regularly, I have little or no desire for alcohol. When I'm not meditating, and my stress level creeps up, I crave a glass of wine with dinner.

Hi Matthew,

Nice quote, I think that's relevant.

Todd Hargrove said...


I have also noticed that my reward needs change over time. Stress definitely raises it, and meditation decreases it.

I may have experienced a general decline in the need for reward after switching to a paleo style diet. Then again, I eat some pretty yummy food now, fat, cream, butter, etc. Perhaps the reward is the same but just from healthier sources.

One thing I can say for sure - I developed a wicked chocolate addiction as soon as I quit wheat!

Jack C said...


Regarding you comments on the food and Diabetes (FAD)study published in 2002 in Diabetologia:

There is no debate about the fact that half of the A2 diets in the study were contaminated is BCM7, the nasty peptide released on digestion of BCM7. The contamination was documented, long before the study was published, by Jeremy Hill who was one of the nine authors and who worked for the New Zealand Dairy Research Institute which was responsible for preparation of the diet. The contamination was known by many of the authors as documented by e-mails.

The only question is whether or not the contamination invalidated the conclusions of the study. One of the authors insists that the conclusions are not valid because of the contamination. Another said that it made no difference, a conclusion that is hard to fathom since if only the properly fed rats are considered, the study shows the occurrence of diabetes significantly higher in the A1 fed rats compared to the A2 fed rats. Most of the authors have been silent on the matter.

I highly recommend the book. It will answer a lot of the other questions you posed.

Jack C said...


The immunological response to BCM7 mostly occurs in the first six months of life because all newborns have a leaking gut during that period which allows them to absorb colostrum. Thereafter the gut tightens up most babies. Because of this it is very important that babies be breast fed at least for the first three months of life.

Babies get their gut flora from their mothers. If the mother has dysbiosis, which is common because of birth control pills, antibiotics and bad diet, the baby will have a leaky gut beyond the three month period and will be much more susceptible to the damaging effects of BCM7.

gunther gatherer said...

Hi Jack and Might-y. BCM7 doesn't have to go through the gut wall to affect opiate receptors. There are millions of them residing right in the gastro tract itself. In fact the gut is where we make about 90% of our serotonin, so leaky gut or not, the BCM7 can still be attaching to hormonal receptors and gumming up the works.

Beth@WeightMaven said...

Stephan/Todd, I've been doing what I call computer-facilitated meditation for a few months now (e.g., using an emWave device that measures heart rate variability while listening to classical music and viewing nature photos).

I'm not familiar enough with how the autonomic nervous works, but I'd imagine that walking around sympathetic dominant all day (like most folks eating a Western diet) contributes to the problem.

And it's interesting how cultural practices like prayers before meals connect to this.

Don said...

So-called 'primal' and low-carb diets can contain plenty of the inherently rewarding items: fat, meatiness, absence of bitterness, soft texture,and caloric density.

People get the idea from various authorities that you can eat as much fat and meat 'as you want' and stay lean. Then they are surprised when they gain weight on their low carb diet. Foods loaded with fat are plenty palatable and easy to overeat. You don't need an excess of insulin to store fat; you can gain with 'enough' (i.e. normal) insulin and an excess of dietary fat.

Galina L. said...

After almost 4 years(actually, 3.5 years) on a low-carb diet, last 4 months of it with IF, I significantly loss my excitement about food. It got especially noticeable after I got used to IF, and it feeds on itself - the more time passes between meals, the more satisfying (satisfying without being exiting)food feels without addition of extra flavors, even something like soft-boiled eggs with butter.I love mutton very much.I normally prepare it on a Foreman grill, and got greedy on couple occasions - cooked 2 blade chops instead of one and couldn't eat second piece each time. Don't do it any longer. Prosciutto is another matter. If I let myself to do it, I would be capable of eating whole 1 lb package piece after piece until it is empty. Probably, some cheeses can have the same effect, nuts too.

Steph said...

GG & Helen, the chapter on a correlation between A1 and schizophrenia was enough for me to get my kids on goats' milk.

I would love for there to be more research on this. As I recall, he said it would take about 10 years to convert all our cows to A2 - that's nothing.

Stephan Guyenet said...

Hi Don,

They can, especially if they're based on processed and restaurant foods, but I think a true paleo diet is pretty low in rewarding properties. Fresh meat is a lot less 'meaty' than most savory processed food, because it contains less free glutamate. That's particularly true if it's lightly cooked. Searing meat or cooking it for a long time increases free glutamate.

In addition, less added sugar and salt, and lower calorie density overall (for many but not all), means that a paleo diet has many fewer rewarding qualities than the typical American diet. If it's based on home-cooked food, it will also be low in those particular flavor-texture combinations that processed food manufacturers exploit to maximize our food intake.

I'm going to argue that lower food reward (relative to the modern US diet) is an important, and perhaps even the most important, characteristic of non-industrial diets when it comes to health.

Stephan Guyenet said...

Just to be clear, I'm not saying that a Cheez-it tastes more like meat than meat itself, just that it has more umami (glutamate) flavor, which is one flavor in meat and an important palatability factor since it's one of the few molecules we have taste receptors for.

Under certain circumstances, rats, cats and other species will overeat and gain fat when their diet is supplemented with MSG. The effect isn't always consistent across studies, which leads me to believe that it's one factor among several (perhaps many) and its effect depends on the dietary context.

Might-o'chondri-AL said...
This comment has been removed by the author.
Robert McLeod said...

Doesn't this support George Bray's notion of 'hedonism' impulses getting into the thermodynamics of food? Colour me suspicious, there's something else in chocolate-flavoured ensure. Is the caffeine content causing those rats to sleep less?

Beth@WeightMaven said...

Re Robert's comment, not sure how much caffeine there is in chocolate Ensure, but just for grins and giggles, I compared the ingredient list of chocolate, vanilla & strawberry Ensure* for differences:

- chocolate lists "Cocoa Powder (Processed with Alkali)"

- strawberry lists FD&C Blue #1, FD&C Red #3, & FD&C Yellow #6

- vanilla & strawberry list Ferrous Sulfate

- chocolate lists Ferric Phosphate


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Carina the Great said...

I can definitely identify with this, as I have been paleo for about a year, and gave up chocolate... or so I thought. Stevia and chocolate powder mixed with yogurt makes for a great so-called "guilt-free" snack. How healthy it is, I could not tell you. I cannot find full-fat yogurt, so I buy one that is 18% MF or whatever, and unsweetened. Man, am I addicted to that so-called "pudding" I make. Every other day, I'm like "man, I need to go out and buy some more yogurt!" I drink kefir regularly, so I can't even say I'm eating yogurt for probiotis... it's a straight-up addiction! lol, I need help.

LoraTX said...

This series is so very informative! It reinforces something I have suspected for a while now. I want to refer people to the site to read it. I wish it was easier to find the whole series though. Maybe a link to the next article could be included with each article in the series?

Keep up the good work!