“It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong.”
-Richard Feynman
An ongoing theme in the LCHF community is that the medical establishment seems hell-bent on ignoring scientific evidence, to the detriment of millions of patients – most of whom should have never even become patients in the first place.
I came across this LCHF hit piece on a website called ‘quackwatch’:
quackwatch.org/06ResearchPr...
It's ten years old, but I thought it would fun to dismantle the argument presented there, because it typifies the current Establishment view. The intent here is not to humiliate Stephen Barrett M.D., but simply to discuss a worn-out set of objections to LCHF, which he presents here in canonical fashion.
Before I do that, it’s important to clarify the meaning of Feynman’s quote above (if you’re not familiar with the name, Feynman was one of the 20th century’s most influential physicists). The scientific process is badly misunderstood today, even by most scientists. The essence of science is not to ask “Why?” questions (as the UK school syllabus insists). Certainly a scientist might have such questions in his head, but science can only answer “Is…?” questions, and the only possible answers it can give you are “No” and “Maybe”. That means that the scientist must frame his hypothesis (the question he wants answered) in a way that makes those answers useful before he does each experiment. Far too much science today is done with the intent of providing positive ‘proof’. That isn’t the way science works.
Let’s get back to Dr Barrett.
“Many promoters of dietary schemes would have us believe that a special substance or combination of foods will automatically result in weight reduction. That's simply not true. To lose weight, you must eat less, or exercise more, or do both. There are about 3,500 calories in a pound of body weight. To lose one pound a week, you must consume about 500 fewer calories per day than you metabolize.”
Let’s try to nail this one down once and for all. First, let’s look at the experimental evidence. You can visit any weight-loss group adhering to the ‘eat less and exercise more’ philosophy, and you will find a bunch of disillusioned, overweight people who have followed the advice to the letter – doing lots of cardio and reducing their food intake by a few hundred calories a day – and the scales aren’t budging. More often than not, they weigh exactly the same as they did at the start of their diet. Even under controlled conditions, experimenters consistently find that dieters don’t lose as much as they ‘ought to’ on calorie-restricted diets: on the average, they lose about half as much as theory predicts, but the average obscures the detail: a few people lose a lot, a majority lose a mediocre amount or none at all, and a few unlucky souls actually gain weight.
So the theory doesn’t agree with experiment. It is therefore wrong. But why is it wrong?
The reason amounts to a subtle failure of logic. The correct phrasing of the ‘calories-in – calories-out hypothesis’ is as follows:
If you are losing weight, you are burning more calories than you consume.
This is simply a mathematical identity. It has no practical implications for dieting, and it is NOT the same thing as ‘if you consume fewer calories than you burn, you will lose weight’, because what you burn is not a constant: your body dials it up and down according to available resources. Not only is it not constant, you can’t measure it (at least not without very complicated equipment). Making things worse, you can’t estimate the energy value in your food with even a modest degree of accuracy. In other words, while it might be theoretically possible to give your body less than it really wants from an arbitrary combination of dietary sources, there’s no simple way of achieving that in practice.
Perhaps more important is that nobody sets out to lose WEIGHT. We want to lose FAT, and the mechanisms involved in fat metabolism and storage are well-known. We don't need to go into them here: suffice to say that a diet of 1200kCal/day of jellybeans and chocolate cake has never been shown to cause dramatic fat loss.
“Most fad diets, if followed closely, will result in weight loss—as a result of caloric restriction. But they are usually too monotonous and are sometimes too dangerous for long-term use. Moreover, dieters who fail to adopt better exercise and eating habits will regain the lost weight—and possibly more. My advice to people who are considering a low-carbohydrate diet is not to try it on their own by reading a book but to seek supervision from a physician who can monitor what they do.”
Now, right off the bat, Dr Barrett has labelled LCHF a fad diet. We expect him to do two things at this point: define what a ‘fad diet’ is, and explain why LCHF is a fad. What we get is something quite extraordinary. A fad diet, apparently, is one that works. The “…as a result of caloric restriction” is a classic red herring: it is irrelevant to the argument. An equivalent sentence would be “It’s true that using proper grammar and spelling in your CV makes you more likely to land a job, but it does so merely by conveying a good impression”.
Now you might say I'm being unkind, and that Dr Barrett is merely pointing out that some diets might get to the right result for the wrong reasons. However this is not an adequate reason for using the word 'fad'. A lot of modern medicine has no valid theoretical underpinning. I hope, for example, that Dr Barrett doesn't accuse his anaesthetist colleagues of quackery, bearing in mind that nobody is quite sure how general anaesthetics work.
Quite reasonably, we’re told that to meet the 'fad' criteria, a diet might be monotonous and/or dangerous. Dr Barrett subsequently describes LCHF as being neither, thus demolishing his own argument. We’ll come to that in a moment.
As an aside, we have the implication that only doctors know how to operate a diet protocol properly. Certainly doctors have an advantage in that they study human metabolism in detail. However, unless they’ve pondered on the practical implications of that study, they won’t necessarily be able to offer good advice. Every physicist graduating in the 1950s was familiar with the concept of stimulated emission, but only one of them invented the laser. Every doctor practicing in the 1970s knew how insulin operates, but only one of them set up a low-carb diet clinic.
Dr Barrett's very existence disproves his thesis: he's a psychiatrist. He not only knows how bodies work, he knows how brains work too; he should understand, for example, how powerful human drives like hunger can affect our behaviour. He has apparently set aside all of his professional knowledge in pursuit of an ideological target.
In the next paragraph, Dr Barrett describes how LCHF produces essentially the same effect as a starvation diet … with the critical difference that it doesn’t actually involve starvation. Or muscle loss.
“The most drastic way to reduce caloric intake is to stop eating completely. After a few days, body fats and proteins are metabolized to produce energy. The fats are broken down into fatty acids that can be used as fuel. In the absence of adequate carbohydrate, the fatty acids may be incompletely metabolized, yielding ketone bodies and thus ketosis. Prolonged fasting is unsafe, because it causes the body to begin to digest proteins from its muscles, heart, and other internal organs. Low-carbohydrate diets also produce ketosis, but if properly designed, they enable the body's nutritional needs to be met by dietary protein, dietary fat, stored body fat, and stored glycogen, so that body muscles are spared.”
We're left to figure out for ourselves why this is a Bad Thing, because the good doctor doesn't explain. More worrying is that Dr Barrett apparently doesn't know that ketone bodies are not some useless product of 'incomplete metabolism' but a source of energy that most of your body's cells can use for fuel.
“As this ‘nutritional ketosis’ begins, there is a diuretic (water loss) effect, leading the dieter to think that significant weight reduction is taking place. However, most of the early loss is water rather than fat; the lost water is regained quickly when if the dieter resumes eating carbohydrate (as would occur, for example, with a balanced diet).”
There are so many red herrings stacking up here it’s all starting to smell quite fishy. Certainly the initial weight loss is water loss, because carb-based diets tend to cause water retention. However you can’t keep losing water indefinitely: as every LCHF dieter knows, it’s all fat after the first two weeks. It is also quite obvious that the weight will come back again if the dieter reverts to his original diet; what this has to do with the effectiveness of LCHF is anybody’s guess. In fact, Dr Barrett seems not to realise what he's said here: he has explicitly stated here that a ‘balanced diet’ will cause weight gain, i.e., it's best to avoid 'balanced diets' if you want to lose weight.
“The dieter is permitted to eat unlimited amounts of noncarbohydrate foods ‘when hungry’, but, as noted above, the diet tends to suppress appetite.”
Another misplaced ‘but’. The correct word is ‘because’.
“Atkins also recommended large amounts of nutritional supplements.”
This is simply untrue. He suggested a multivitamin pill, additional salt, and beef broth during induction to alleviate transient discomfort during the adaptation period. Subsequent research has found that the vitamin pill really isn't necessary.
Now we come to the evidence for Dr Barrett’s position, in which we expect to see LCHF demolished as both monotonous and dangerous:
“Noting that the diet could produce short-term weight loss, they [the AMA] thought that long-term use would probably increase the risk of both cardiovascular disease and cancer [6]. However, clinical trials have not upheld this prediction.”
So … um, it isn’t dangerous then. But wait! The American Heart Association “has issued a science advisory warning that high-protein diets have not been proven effective and pose health risks”. Let’s have a look at their objections:
'Such diets may produce short-term weight loss through dehydration.'
-We did that one already. Worth pointing out that 'losing excess water' is not the same thing as 'dehydration'.
'Weight loss may also occur through caloric restriction resulting from the fact that the diets are relatively unpalatable.'
-Again with the ‘unpalatable’. This is in comparison to, we assume, the small portions of stodge-based meals, with all the nice bits removed, that the AHA has traditionally recommended.
'The high fat content may be harmful to the cardiovascular system in the long run.'
-Except that that hypothesis was dismissed by experiment. It's wrong, and the AMA accepted that it's wrong.
'Any improvement in blood cholesterol levels and insulin management would be due to weight loss, not the change in composition.'
-Another red herring. As long as it happens, that's a desirable outcome; if it's due to aliens arriving to administer liposuction, who cares?
'A very high-protein diet is especially risky for patients with diabetes because it can speed the progression of diabetic kidney disease.'
-Possibly. It’s a good thing LCHF isn’t a high-protein diet then, isn’t it? This argument is technically known as a strawman: setting up a caricature of the thing you dislike, and then destroy the caricature.
Perhaps the most intriguing statement about the ‘danger’ of LCHF is this one, in which the experimenters find that low-carb diets improve the accepted risk markers for heart disease:
“In 2002, a 6-month study funded found that followers of the Atkins diet lost more weight than comparable people on a high-carbohydrate diet and improved their blood cholesterol and triglyceride levels [12]. However, the dropout rate was much higher in the low-carbohydrate group and the improved lipid levels did not necessarily mean that the diet would have a cardioprotective effect in the long run”
Let’s be clear about the meaning of the final sentence: improving lipid levels may not, in and of itself, improve outcomes in CVD. In fact, this is a properly cautious scientific statement. Yet the underlying assumption in current medical treatments is that improving the lipid profile is all-important. It is THE goal of statin therapy.
There are numerous experiments demonstrating that the answer to the question “Does LCHF produce a worsening lipid profile?” is No:
ncbi.nlm.nih.gov/pubmed/196...
So let’s go back to the alleged ‘monotonous’ character of LCHF. Here’s a wonderful quote:
“Another study ... followed 18 Atkins dieters for a month… dieters in both phases cut back on carbohydrates by more than 90%, but the actual amounts of fat and protein they ate changed little. Some patients felt tired, and some were nauseated on the plan.”
Since the “actual amount of fat” changed little, they clearly WERE NOT ACTUALLY DOING Atkins. They’d just stopped eating anything their bodies could use for fuel. Another strawman. Next.
Oh. There isn’t a Next. Not a single example of a LCHF meal. All we’ve got here is the opinion of some unimaginative people who can’t conceive of anything other than margarine sandwiches for lunch and chicken breast with rice and boiled vegetables for dinner. Which – I don’t know, call me picky – strikes me as a bit monotonous.
Well, let’s wrap this up, because the rest of Dr Barrett’s article doesn’t get much better.
In closing, he takes a final dig at Dr Atkins:
“Atkins advocated his diet for more than 30 years and stated that more than 60,000 patients treated at his center had used his diet as their primary protocol. However, he never published any study in which people who used his program were monitored over a period of several years. It would not have been difficult for him to compile simple data, but I have seen no evidence that did so.”
… despite previously noting:
“In 1999, Atkins set up a foundation to provide ‘funding for research and education on the role of controlled carbohydrate nutritional protocols in treating and preventing a wide range of medical conditions.’ The availability of funds has generated responsible research.”
Just in case we hadn't quite got the message, he makes it quite clear that he’s missed the whole point of LCHF:
“Most of these [low-carbohydrate foods] are much higher in fat than the foods they are designed to replace.”
Why is this a problem? Well:
“I believe that ‘low-carb’ advertising is encouraging both dieters and nondieters to eat high-fat foods, which is exactly the opposite of what medical and nutrition authorities have been urging for decades.”
So there you have it. Dr Barrett has written an entire article listing research that shows LCHF to be both safe and effective. But LCHF conflicts with official advice, and that, it seems, is the REAL defining characteristic of a fad diet. Let's be clear about the implication of this: it is not permissible to challenge received opinion using scientific evidence, because any diet producing such evidence is a 'fad'.
I’m new here and getting with the programme
Weight loss slow- I don’t think I’m doing it right