Dr. George Bray's model of obesity
In July 2008 I posted on Dr. George BrayÂs critique of Gary TaubesÂ book Good Calories, Bad Calories that appeared in Obesity Reviews.Â Included in my post was a copy of GaryÂs response.Â Now Dr. Bray is back with a rebuttal to GaryÂs response to his (BrayÂs) original critique.Â In conversation, Gary told me he has elected to drop the issue because the discussion is going nowhere.Â Gary makes substantive points; Bray obfuscates the issues and will continue to do so.Â I, however, am not going to drop the case.Â Maybe IÂll have the last word here.
I want to go over Dr. BrayÂs response to GaryÂs letter in some detail because it is emblematic of all that is wrong with obesity research today and clearly demonstrates why we will never get anywhere until the people of BrayÂs generation fade away. I donÂt know that IÂve ever seen so many instances of one writer missing the point as often as Dr. Bray does in this short reply.Â The entirety of his response is an example of either shoddy thinking or intellectual dishonesty.Â Or maybe both. It brings to mind Mary McCarthyÂs famous quote about Lillian Hellman: ÂEvery word she writes is a lie, including ÂandÂ and ÂtheÂ.
(You can read Dr. BrayÂs original critique of Good Calories, Bad Calories along with GaryÂs response in my July 2008 post.Â The full-text of Dr. BrayÂs letter of reply weÂll be discussing in todayÂs post can be found here.Â You should pull it down in pdf and print it so you can follow along.)
Right off the bat, in the very first line, Bray leads off with his first porkie.
In his nearly 5000-word response to my book review, Mr. Taubes has raised a number of issues.
GaryÂs response was slightly under 2000 words.Â You might think this just simply a typo, and normally I would too, but the entire piece is filled with so many inaccuracies seemingly designed to denigrate GaryÂs response that I donÂt think so.Â Why even put the number of words?Â Why not simply say: In his response to my book reviewÂ
?Â By quantifying the number of words the way he does, Bray casts a pejorative shadow on GaryÂs response from the get go.
If you read GaryÂs letter, you will see that he methodically refutes Dr. BrayÂs criticisms of GCBC and identifies those issues in which he feels Bray misses the point.Â In his response, Bray says GaryÂs critique of his (BrayÂs) review of GCBC
opened the door for [him] to contrast [TaubesÂ] hypothesis for obesity with [his own].
ItÂs a kind of disingenuous way for Bray to get his own hypothesis of obesity into play in what amounts to a review of GaryÂs book, but letÂs take a look at what he has to say.Â First, he completely simplifies and basically mischaracterizes GaryÂs hypothesis of obesity.Â Here is GaryÂs hypothesis of obesity and his proposed treatment as interpreted by Dr. Bray:
As you can see, it appears pretty simplistic, which, IÂm sure, was the intent.Â Not shown are all the feedback loops and intricacies Gary has described at length in GCBC .
In referring to this diagram, Dr. Bray admits that it is based on Âtwo sentences from the letter,Â which doesnÂt seem like a lot out of a 5,000-word letter (or even the 2,000-word letter that it was).Â Then he goes on to use three sentences to establish the basis for the diagram.Â (See what Mary McCarthy meant about even ÂandÂ and ÂtheÂ?)
After giving short shrift to GaryÂs hypothesis of obesity, Dr. Bray then goes on to lay out in great detail his own theory of obesity as represented by the Rube Goldbergesque diagram at the top of this post.Â BrayÂs entire hypothesis, for which he recruits leptin, insulin, the brain, glucocorticoids, and God knows what else to help make his point, is based on a faulty premise.Â But itÂs a faulty premise he has accepted uncritically.
His hypothetical model of obesity, he authoritatively states
starts with the First Law of Thermodynamics, which states that the change of energy in a closed system is the difference between the heat added to the system and the work done by the system.
Dr. Bray then restates this hypothesis (and the First Law) in the form of this equation:
Δ E = Heat (q) Â Work (w)
Readers of this blog know this as the energy balance equation, which looks like this in its more familiar form:
Δ Weight (the Δ means change) = Energy in (food) Â Energy out (exercise plus metabolism)
The fatal flaw in Dr. BrayÂs hypothesis (which is a flaw weÂve discussed often in these pages) is that he doesnÂt understand that the components on the right side of the equal sign are not independent variables.Â They are dependent variables.Â If one eats less, the rate of metabolism falls to compensate.Â If one exercises more, the appetite increases, and one eats more to compensate.
Were these components truly independent variables, life would be easier (but we may not have survived).Â According to Dr. Bray, Anthony Colpo, and countless others, however, these components are independent variables.Â Eat less, say they, and youÂll lose weight.Â Which is true, to a point.Â But once the energy-out component of the equation kicks in, weight loss stalls, even if you are eating less, a fact everyone who has ever dieted knows.Â Exercise more, they pontificate, and youÂll lose weight.Â Which, again, works (maybe) in the very short term.Â But once appetite kicks in, you unconsciously eat enough more to compensate for your increase in exercise, as anyone knows who has tried to lose weight by walking or other exercise alone without consciously restraining eating.
Now donÂt get me wrong, it is possible to lose weight by decreasing food intake and increasing exercise.Â It worked well in the concentration camps in WWII and in Ancel KeysÂ starvation studies in the 1940s.Â But in those cases, people were under lock and key.Â It doesnÂt work for the long term for the majority of people unless they are coerced.
This fairly obvious observation that the energy in/energy out components are not independent variables seems to elude most (if not all) obesity researchers, including George Bray.Â These people persist on basing the foundation of any obesity treatment on the admonition to eat less and exercise more, which is a total folly.Â Yet Bray and his ilk continue to clothe this folly in the garments of academic respectability and work to pass it off as the latest fashion in scientific thinking.
Dr. Bray believes that the reason so many people are fat is twofold. First, he thinksÂ humans have a ÂhedonicÂ drive that inexorably pushes them to increase their food intake.Â And, second, he reckons that this ÂhedonicÂ drive also overrides the Âappropriate negative feedback signals to stop eating.ÂÂ What stimulates this ÂhedonicÂ drive?Â According to Dr. Bray
It is caused by the pleasurable effects of high-fat, high-sugar foods.
Well, at least heÂs half right on that one.Â No one binges on pure fat.Â ItÂs impossible because of feedback inhibition to eat a lot of pure fat at a sitting.Â Try sometime to sit down and eat some butter all by itself.Â See how much you can choke down.Â I can guarantee you it wonÂt be much.Â Then add a little sugar to the mix and see what happens.Â Suddenly the butter is converted to frosting, and you can put away a lot of it.Â WhatÂs the difference?Â ItÂs the sugar.Â Sugar – and carbohydrates in general – override the stop-eating center in the brain.Â ThatÂs why all binge eaters binge on a combination of fat and carbohydrate.Â ThatÂs also why you can go out to dinner, eat Âtil your stuffed, not be able to eat another bite of any kind of meat or other real food, yet perk up when the dessert tray comes around.Â As the old saying goes: thereÂs always room for dessert.Â Why? Because your brain knows the stop-eating center will be overridden by the sugar and carb in the dessert.
Dr. Bray would have been more accurate had he said that the stimulus for the ÂhedonicÂ drive is carbohydrate.
But he doesnÂt.Â He is trapped in the fat-is-bad paradigm.
In experimental animals, highly palatable food or a high-fat diet is one of the easiest ways to disturb this homeostatic system [as defined by Dr. Bray], and this may apply to human beings as well.
Dr. Bray seems to believe that we live in a toxic world in food terms.Â We are unable to help ourselves, and are therefore destined to be fat because of our ÂhedonicÂ drive.Â We are helpless.Â There is no cure save eating less and exercising more, which even he more or less admits doesnÂt work despite his entire model being based on the idea.Â As I have discussed in another post, Dr. Bray is a major proponent of drug therapy to treat obesity.
In a way, I agree with him about the idea that we live in a toxic world, one with all kinds of the wrong kinds of food available to tempt us 24/7.Â Problem is that Bray and his ilk are a major part of the reason we live in such a world.Â But thatÂs a topic IÂll leave for a future post.
Dr. Bray makes a bizarre case for why he thinks the majority of dietary studies show better results in those subjects following low-carb diets than in those consuming low-fat regimens.Â IÂm going to use his own words, so you wonÂt think IÂm making this up.
the principal studies that directly support this model [TaubesÂ theory on low-carb dieting] included the word ‘Atkins’ in their clinical trial. When similar low-carbohydrate diets were tested without using this ‘name’, the low-carbohydrate diets had no more effect than those to which they were compared.
There you have it.Â All you have to do to make a diet work is include the name ÂAtkinsÂ in the title.Â I wish MD and I had known that when we wrote Protein Power.
What is truly ironic about this nonsense is that in this very same issue of Obesity Reviews containing BrayÂs rebuttal is a long review article titled Systematic review of randomized controlled trials of low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities.Â This article takes an in depth look at studies comparing low-carb diets to low-fat diets.Â Here is the conclusion as written in the abstract:
There was a higher attrition rate in the low-fat compared with the low-carbohydrate groups suggesting a patient preference for a low-carbohydrate/high-protein approach as opposed to the Public Health preference of a low-fat/high-carbohydrate diet. Evidence from this systematic review demonstrates that low-carbohydrate/high-protein diets are more effective at 6 months and are as effective, if not more, as low-fat diets in reducing weight and cardiovascular disease risk up to 1 year.
Dr. Bray lists five other issues about GaryÂs letter to which he wishes to respond, but before he gets to the list, he makes one last flippant point.
I thus conclude that if any diet ‘cured’ obesity as their proponents often claim, there would be no obesity and thus no need for the next diet. Yet the past 150 years, since the publication of Banting’s first popular diet, have seen a continuing stream of new diet books.
The reason, of course, is that we dieting fish all swim in waters that have been polluted by Bray and his brethren, more about which in a later post.
Now to the list.
1.Â Â Â Near the end of the letter, Mr Taubes suggests that my review of his book may be a ‘conflict of interest’. He says ‘I [Bray] may be defending what my scientific research has led me to believe’. If this is a conflict of interest, then all scientists have a conflict of interest.
This first short point of only three sentences tells you everything you need to know about Dr. BrayÂs scientific credibility.Â I have no problem with the first sentence.Â The second sentence is purportedly a quote from Gary Taubes letter.Â It isnÂt.Â It is a paraphraseÂ
sort of, but put in quotation marks.Â This is a real no no.Â It was done so for a particularly egregious reason, which was for a set up for BrayÂs final sentence.Â But that sentence even further diminishes his credibility.Â Scientists are supposed to constantly challenge their own hypotheses, not accept them as fact simply because theyÂve spent their careers enraptured with them.Â Â All true scientists donÂt have this conflict of interest.
2.Â Â Â The first paragraph of his letter dealt with lipoproteins that I said he had not covered. The issue was not the lipoproteins but their receptors, from which we have learned so much in the past 30 years.
This one is a real copout.Â In BrayÂs original critique he wrote:
As I read through Good Calories, Bad Calories, I found a number of errors of omission or commission that are important when relating diet to heart disease.Â There is no mention in the Diet-Heart section of low-density lipoprotein-cholesterol (Âbad cholesterolÂ) or of high-density lipoprotein-cholesterol (Âgood cholesterolÂ).
The issue may have been the receptors and not the lipoproteins, but as you can see from his direct quote above, thatÂs not how Bray characterized it.Â Gary set him straight with a list of about two dozen pages and groups of pages where LDL and HDL were mentioned, yet Bray weasels instead of admitting his mistake.Â When I read his first letter, it made me wonder if he had even read the book.
3.Â Â Â In his letter he mentions doubly labelled water only to conclude that we knew this already from the 19th and early 20th century and he did not need to discuss it in his book. I would submit that we did not know that people under-report their intake by as much as they do and that overweight people under-report more than normal-weight people do.
Okay.Â ThereÂs a total non sequitur.Â What does the second sentence have to do with the first?Â Weird.Â Was Bray on dope when he wrote this?
4.Â Â Â Mr. Taubes say Âthe goal of science is to determine causalityÂ
(What Gary actually wrote was ÂThe goal of science is to correctly determine causality,Â but whoÂs counting?)
Then Bray wades into this strange discourse about the theories of Karl Popper, whom he misnames as Hans Popper.Â (Does this guy ever bother to look anything up?)
This is significantly different from the views of Hans Popper, the philosopher of science, whose search is for ‘reality’ rather than ‘causality’. Popper says ‘there is a reality behind the world as it appears to us, possibly a many-layered reality, of which the appearances are the outermost layers. What the great scientist does is boldly to guess, daringly to conjecture, what these inner realities are like. Popper also espouses the concept of ‘falsification’, which is at the heart of rationalist thought. To quote him again Â’a false theory may be as great an achievement as a true one. And many false theories have been more helpful in our search for truth than some less interesting theories which are still accepted’.
If you can make sense of this gibberish, youÂre a better man than I am.Â All I know is that Bray misses PopperÂs point about falsification in a major way.Â (We discussed Popper and his theory of falsification in an earlier post.Â And it ainÂt anything like Bray makes it out to be. I seriously doubt he has even read Popper’s work.)
The last sentence of the above paragraph I find particularly interesting.Â Writes Bray, apropos of nothing really:
And many theories have been more helpful in our search for truth than some less interesting theories which are still accepted.
I donÂt know about the search for truth, but I can tell you that the inability of Bray and the rest of the academic obesity ÂexpertsÂ to shake loose from their own Âless interesting theoriesÂ have led us into the obesity epidemic weÂre in the throes of now.
Dr. BrayÂs fifth comment, which IÂm not going to reproduce in full, is a world-class case of totally missing the point.Â After commending Gary for proposing an experiment to validate his hypothesis, he goes on to quote GaryÂs rebuttal letter:
He says Âthe positive energy balance hypothesis of obesity asserts that the only way to lose excess fat is to eat less and/or exercise more Â that without consciously inducing a negative energy balance we will not lose weight’. His hypothesis is ‘the carbohydrate/insulin hypothesis asserts that if we restrict carbohydrates in the diet/and or improve the quality of the carbohydrates consumed then insulin levels will be lowered, reducing the accumulation of fat in the fat tissue independent of the nutrition state of the subject’. I would take exception to his use of the word ‘consciously’ in his statement of the energy balance hypothesis. For example, the current level of oil prices may increase human energy expenditure through more walking as it decreases automobile use. This is not a ‘conscious’ choice in the sense used above but would have the same effect.
Let me get this straight.Â Dr. Bray thinks if we walk more because we decrease automobile use as a consequence of the high price of gasoline that weÂll lose weight because we are unconsciously exercising instead of volitionally exercising?Â As I say, he misses the point, which is that the two components on the right side of the energy balance equation are not independent variables, but are dependent variables.Â It doesnÂt matter if one walks as a part of exercise or because one canÂt afford the gas, the body compensates by increasing food intake.
Dr. Bray ends his response by resorting to the old conservation of energy principle, which all the eat-less, exercise-more folks hew to.Â They seem to believe that no one who advocates low-carb diets can understand the laws of thermodynamics when it is they themselves who donÂt understand them as applied to diet.Â There is nothing inconsistent with GaryÂs theories of the cause and treatment of fat accumulation and the laws of thermodynamics.Â ItÂs Bray and friendsÂ lack of understanding of these laws and/or their refusal to accept the dependent nature of the energy in/energy out components of the energy balance equation that are the heart of the problem.
This entire rebuttal of Dr. BrayÂs reminds me of my own favorite lines from Good Calories, Bad Calories.Â They are my favorite because IÂve seen first hand what they describe.
The institutionalized vigilance, Âthis unending exchange of critical judgment,Â is nowhere to be found in the study of nutrition, chronic disease, and obesity, and it hasnÂt been for decades.Â For this reason, it is difficult to use the term ÂscientistÂ to describe those individuals who work in these disciplines, and, indeed, I have actively avoided doing so in this book.Â ItÂs simply debatable, at best, whether what these individuals have practiced for the past fifty years, and whether the culture they have created, as a result, can reasonably be described as science, as most working scientist or philosophers of science would typically characterize it.Â Individuals in these disciplines think of themselves as scientists; they use the terminology of science in their work, and they certainly borrow the authority of science to communicate their beliefs to the general public, but Âthe results of their enterprise,Â as Thomas Kuhn, author of The Structure of Scientific Revolutions, might have put it, Âdo not add up to science as we know it.Â
The result is an enormous enterprise dedicated in theory to determining the relationship between diet, obesity, and disease, while dedicated in practice to convincing everyone involved, and the lay public, most of all, that the answers are already known and always have beenÂan enterprise, in other words, that purports to be a science and yet functions like a religion.
Is it any wonder that Dr. Bray didnÂt enjoy the book?