Not too long ago I read an interesting article in the New York Times entitled In Dieting, Magic Isn’t a Substitute for Science. It starts with a question that deserves a thoughtful answer:
Is a calorie really just a calorie? Do calories from a soda have the same effect on your waistline as an equivalent number from an apple or a piece of chicken?
The reason the NYT is even asking this question now is because of the research that recently came out that seems to indicate that high protein or Atkins-like diets have a small metabolic advantage over simply calorie-counting.
Now – the study was small – it is really, really hard to do this sort of research. Expensive and time-consuming – and unless you do these studies on prisoners, it’s hard to be sure exactly what these subjects ate exactly. Nonetheless, it is an interesting finding, when put into perspective as less than definitive.
The NYT talked to Dr. Jules Hirsch, emeritus professor and emeritus physician in chief at Rockefeller University, who has been researching obesity for nearly 60 years, who quickly dismissed this study as so much hogwash.
Now, I don’t want to be accused of taking a cheap shot at a gentleman I do not know, but the good doctor has been involved in research for 60 years, during which time the population has only gotten fatter. Something’s going on here:
- Nobody listens to him
- People listen to him, but his advice cannot be followed and is unrealistic
- There is a fundamental flaw in his thinking on obesity
From the article, here is journalist Gina Kolata’s question – and the gentleman’s answer:
The JAMA study has gotten a lot of attention. Should people stay on diets that are high in fat and protein if they want to keep the weight off?
What they did in that study is they took 21 people and fed them a diet that made them lose about 10 to 20 percent of their weight. Then, after their weight had leveled off, they put the subjects on one of three different maintenance diets. One is very, very low in carbohydrates and high in fat, essentially the Atkins diet. Another is the opposite — high in carbohydrates, low in fat. The third is in between. Then they measured total energy expenditure — in calories burned — and resting energy expenditure.
They report that people on the Atkins diet were burning off more calories. Ergo, the diet is a good thing. Such low-carbohydrate diets usually give a more rapid initial weight loss than diets with the same amount of calories but with more carbohydrates. But when carbohydrate levels are low in a diet and fat content is high, people lose water. That can confuse attempts to measure energy output. The usual measurement is calories per unit of lean body mass — the part of the body that is not made up of fat. When water is lost, lean body mass goes down, and so calories per unit of lean body mass go up. It’s just arithmetic. There is no hocus-pocus, no advantage to the dieters. Only water, no fat, has been lost.
Reading this carefully, the comparison of diets was done AFTER the subjects lost 10 to 20 percent of his body weight. I might be a dope, but I’m pretty sure that the first weight taken off on ANY diet is the water weight. Certainly Atkins helps you shed water. Is he saying that the Atkins dieters *continue* to lose water weight after losing 10-20% of their body weight? I maybe wrong, but I find that a bit hard to believe, no? Am I missing something here?
The interview continues:
So the whole thing might have been an illusion? All that happened was the people temporarily lost water on the high-protein diets?
Perhaps the most important illusion is the belief that a calorie is not a calorie but depends on how much carbohydrates a person eats. There is an inflexible law of physics — energy taken in must exactly equal the number of calories leaving the system when fat storage is unchanged. Calories leave the system when food is used to fuel the body. To lower fat content — reduce obesity — one must reduce calories taken in, or increase the output by increasing activity, or both. This is true whether calories come from pumpkins or peanuts or pâté de foie gras.
To believe otherwise is to believe we can find a really good perpetual motion machine to solve our energy problems. It won’t work, and neither will changing the source of calories permit us to disobey the laws of science.
The certainty here smacks of arrogance. His derision is hubris. From Wikipedia:
hubris often indicates a loss of contact with reality and an overestimation of one’s own competence or capabilities, especially when the person exhibiting it is in a position of power.
If I were to talk to this gentleman – surely a nice person as long as you don’t disagree with him without having the requisite degrees and experience necessary for him to deem you worthy of discourse on the subject, I would ask him:
What about absorption? Yes – I know physics and I know that energy taken in must go somewhere. What you neglect to mention is our incomplete understanding of what makes us absorb calories and what makes us excrete calories. If you read a bit farther in your physics book – or maybe cracked open an engineering book, you would know that there is the notion of ‘efficiency’ in all mechanisms. A car, for example, does not utilize fuel with 100% efficiency. The heat that radiates off your engine is wasted energy, for example. In fact, engineers have designed the most current hybrid cars to try to use the energy lost in braking to charge the batteries of the cars.
To look at the human mechanism, we have a metabolic rate, and we have a level of metabolic efficiency where a certain percentage of calories consumed are excreted.
One example: people with hyperthyroidism can lose weight even though they are eating as much as they used to – or even more.
There is also a term – Diabulimia – that is used to describe an eating disorder in type 1 diabetics. They withhold insulin so they can eat what they want and lose weight. Here’s a snippit of the article:
Bulimia is a disorder in which a person eats and then purges, usually by vomiting or abusing laxatives. In diabulimia, the tool used to purge calories is simply to cut back on insulin. “It’s extraordinarily successful and quite addictive,” says Polonsky. “But it can harm you terribly in the near-to-long term. It is so scary and hard to treat.”
Diabetes: The Insulin and Weight Loss Connection
People with type 1 diabetes need daily insulin doses to live. In this type of diabetes, the pancreas doesn’t produce insulin, the hormone the body needs to absorb glucose (sugar) and use it as energy or store it as fat.
If insulin is used appropriately, the glucose is absorbed from the blood into the body’s tissues and used (or stored). Without insulin, the glucose builds up in the blood and is excreted in the urine. This can cause dramatic weight loss. So it’s understandable why some diabetic women would be tempted to drop insulin doses to lose a dress size.
(Quickie note to any type 1 diabetics who suddenly think they have a nifty new way to shed some pounds – don’t. This is so dangerous and causes so much long-term irreversible damage to your body that it will put you in an early grave – a *very* early grave.)
So you’re right – the energy has to go somewhere. It can be stored as fat, and it can be expended as exercise as you say.
Calories can also be excreted in the urine – as in the diabulima example above – or it can be excreted in the feces. A number of calories are known to be excreted in the feces as was shown in a series of experiments done in the late 1800s by Wilbur Olin Atwater – the inventor of our modern notion of a calorie.
Mr. Atwater came up with an efficiency number basically by feeding subjects food then measuring the energy in their poop – and our current notions of calories are still based on his calculations, as far as I know.
But human beings are quite variable creatures – who’s to say your absorption is the same as another persons’? Who’s to say that it cannot be changed?
By trotting out ‘immutable laws of physics’ you end discussion – a discussion that is still worthy of debate – one that the book should not be closed on.