It's also wrong. At least, it's not the truth, the whole truth and nothing but the truth.

I was watching a video of a Gary Taubes lecture which I can't find where he addresses this, and cites many examples from history of societies and situations where groups of people were fat despite eating very few calories, where groups of people grew fat as their diet changed despite the calorie count not increasing, and vice-versa.

I think this is the same talk:

http://video.google.com/videoplay?docid=4362041487661765149

It just turns out to be really, really, really freakin' hard to do that, and there are any number of fascinating little details you can explore to avoid facing up to that basic truth. Really, I think we're just too hard on ourselves. I think we'd make a lot of progress if we'd just admit that we have a problem saying no. I'll be honest about my problem with food: right now I'm almost ten pounds heavier than when I was in my best shape, which probably means twenty pounds over my ideal weight. I got injured playing sports, couldn't exercise much for two months, got depressed, and gained ten pounds. Now I'm in the process of taking it off. How much I eat is roughly a function of how optimistic I feel about my life, so my weight wanders up and down within a fifteen pound range. (However, the top of this range is 25 pounds less than I weighed ten years ago, so it's not like I haven't made any progress.)

I know exactly what I need to do to get in the best shape of my life by October, without taking any time away from my other priorities. Maybe it will happen, but the smart money says no. This isn't a problem of nutrition or exercise physiology -- those problems are solved. It's a problem of psychology. The only reason people deny it is because they're ashamed that they aren't in complete control of themselves.

Watch the video I linked.

That there are people who can die of starvation while still being obese, people who can be eating 1200-1400 calories per day and still not be losing weight, modified rats that can be starved while growing up and end up with smaller internal organs and still large fat deposits - that's not a "detail". That's not eating too much and gaining fat, (but with a couple of minor exceptions). That's a fundamental problem with the idea that eating too much leads to being fat, and eating less leads to losing fat, the end.

The equation, energy delta equals energy in minus energy out doesn't change, but the causal relationship and the whole perception of it changes. It's not energy in that's driving the equation.

As Gary Taubes says - when a child is growing and eating voraciously, we don't say they are growing because they are eating more.

"To explain obesity by overeating is as illuminating a statement as an 'explanation' of alcoholism by chronic overdrinking."

Then he attacks the idea that behavior is unrelated to physiology -- where did he get that straw man? As far as I know, everyone who blames obesity on overeating also believes that the amount we eat is affected by many factors, including physiology. So please tell me, before I watch the rest of the video, does he really disagree with the idea that obesity is caused by overeating, or does he merely believe that saying so doesn't do justice to the fact that overeating has complex causes of its own?

I don't want to get into a miscommunicated argument of language here, but he's more pushing for the idea that it's caused by overeating high glycemic load foods, and that this overeating can happen even within a diet where someone is eating a total amount food that would be called undereating or normal.

He's going to go on to say that it's not simply eating food -> storing fat, it's dependent on insulin causing cells to take glucose from the bloodstream, and the result of fat cells doing this is an increase in availability of {some_chemical} which increases the drive to store free fats in fat cells, rather than not doing so. As you eat foods that raise blood insulin levels, your fat storage grows and is prioritised, and you want to eat more.

But even if you don't eat more, food is being stored as fat as a priority instead of doing other useful things with it, so you can undereat and be both obese and malnourished, by eating the wrong types of food. Or you can eat more and have ordinary "eats too much, is too fat" obesity.

He's not arguing for a cause by aliens or bacteria or anything very different, but I think this model is a useful enough distinction from the model of "more food calories in than you use everyday -> fat storage, less food calories in than you use everyday -> fat burning" to say that he really does disagree.

You can induce all kinds of freakish pathologies by eating the wrong types of food; that's nothing new. Simultaneous obesity and malnourishment is common in poor communities in the U.S. because of diets that are high in calories but deficient in other ways. I seriously doubt anyone could be obese and calorie-malnourished in the absence of serious medical issues or radical inconsistency in food availability. The existence of odd pathologies like Taubes' lipodystrophy cases doesn't say anything about the vast majority of people.

Taubes acts like the mere existence of these pathologies is mind-blowing. But it's just common sense: the process of storing and metabolizing body fat isn't physically inevitable. It's complicated. There are all kinds of ways it could be suppressed, and you expect that as with any other biological process, there's going to be natural variation in the population, including people where the process goes wrong in an odd way. That isn't a daring supposition. That's just the way any ordinary doctor or biologist would think. The question is dealt with every time a new drug is studied -- how will different people respond to it? Vioxx was a scandal because detecting rare harmful side effects of treatments that work well in most people is routine. The idea that a "healthy" diet might harm some people, especially people already suffering from a metabolic disorder, would not blow anyone's mind. Look at all the research into nutrition for diabetics!

Anyway, I still don't see anything new here. Theoretical speculation is fine and dandy, but the question is, what actually happens? If you practice reasonable calorie restriction on a reasonable diet, your body will adjust. It will not kill you or permanently harm you. It will certainly threaten you and try to convince you that you're dying. Everybody knows that when you decrease your food intake, your body complains. It tries to make you eat more. It makes you feel tired. It makes you feel like exercising would be a bigger mistake than drunk-dialing your boss's teenage daughter. But if you go against those feelings, your body's doomsday predictions don't come true. If the situation described by Taubes actually prevented healthy weight loss -- your body starving certain systems of calories in order to spare body fat -- you would expect that people following reasonable diets and exercise could end up unhealthy. And it doesn't happen.

That isn't just an assumption. There are some seriously strong-willed people out there who are pathologically devoted to low body fat and/or suffer from body dysmorphic disorders. There are also some seriously strong-willed people who are dedicated to athletic performance but rather dumb about how they pursue it. We know people can persist in unhealthy habits to the point of breakdown -- it happens all the time. It's not like there's a great uncharted domain out there of freakish consequences that could result from weird practices. Crazy, stupid, and/or mentally ill people have explored the weirdo options pretty thoroughly, sometimes with gruesome results. So why haven't we seen any gruesome outcomes from the diets that are considered healthy according to the conventional wisdom? The only possible conclusion is that whatever pathological responses our bodies might have to healthy diets -- such as starving important systems to spare body fat -- don't persist over the long term in people with an overabundance of body fat.

In any case, from an overweight person's point of view rather than a public policy standpoint, the only practical question is what will happen if you eat a reasonable diet and exercise. The answer is that if you follow any one of a bunch of reasonable diets, from Ornish to Atkins, you will lose weight and be healthier, and if you exercise, you will be even healthier. I get annoyed when people like Taubes, knowing how eager people are to believe otherwise, go through a complex song and dance that encourages people to believe otherwise even though he doesn't seem to believe otherwise himself.

However, I think what the article is talking about is skinniness as opposed to being "chubby" or "soft," not flat out obese. If you're somewhere in the region between "skinny" and "chubby," but not near being under- or overweight, then what you eat and how you exercise is important; even subtle changes to your routine can have noticeable effects.

And then you still burn a huge chunk of free time accomplishing no tangible thing in exchange for a dubious assurance of a fractionally longer life.

I used to be in much better shape than I am now, but my life was miserable. Exercise did not make me feel better, coming to terms with my life and my environment and having some control over my situation made me feel better. My opinion has been that the "workout high" is more about having control over yourself and your situation than any real lasting benefit.

So if you want to have an enormous, 1500 calorie meal at a casual dining restaurant, go for it, just keep it light for the rest of the day.

Yeah, I'm also a 6'3'' and I was 220 in March so I'm probably grossly undereating but after a week of hunger and headrushes you get used to burning fat (I also drink coffee) for energy and feel great while losing weight.

The only reason you'd have to give up certain delicious things is if you were a strict vegetarian -- eating a low-calorie vegetarian diet and getting enough protein isn't rocket science, but it doesn't leave any room for splurging on empty calories.

You already said you enjoy outdoor activities. Isn't that exercise? If you limit the definition of exercise to joyless and repetitive activities with no intrinsic interest, then I have to agree with you that exercise is not worth it.

I agree with this statement, but I'm responding to the article's specific brand of exercise, not exercise in general. Personally, I am on a slow downward trend in weight because I'm making an effort to do things I like and pick and choose my foods more carefully.

I am just tired of people like the poster, who literally play both sides of the fence in one article ("I demand credit for the effort I make to make my body look this way" vs. "I am not a health freak.") I also find it funny how inevitable the course of those posts are. It would have a been a good article if he hadn't made the transition from descriptive to prescriptive, but he did and here we are asking, "Why on earth would I inflict LL Cool J on my ears in 2009?"

I sympathize with the poster. I'm tired of people treating me like a freak just because I care about my weight and have actually accomplished something in that direction. I used to be a mess (5'9" and over 200 lbs, on a relatively small frame) and now I'm much better -- still overweight, but in better shape than some of my friends. That creates some resentment for people around me who are self-conscious about their weight. I'm expected to completely avoid talking about my efforts to get in better shape. It's not a matter of demanding credit; they simply don't want to hear that I have to work at it! When I have a beer with them and they ask me how I'm feeling, they don't want to hear that I had a good run this morning, or that I feel bad because I had a bad run. Okay, fine, I get it, I won't mention it.

But what can you really do? You can't do a Jedi mind trick when you wheel your bike into work. "This isn't a bike. This is just something I found in the parking lot, after I parked my car." What do you say when somebody asks what you were doing when they left you a voice mail earlier? "Uh... stuff. Yeah, I was doing stuff." When somebody asks you why you didn't eat all the fries that came with your burger, are you supposed to lie and say you didn't like them? There's no way to completely hide the fact that yes, you are trying to do something a little different.

Plus, the same people who get annoyed when I talk about my struggles with my weight feel free to talk about their own. They want to talk about their efforts at diet and exercise as if it's normal, but we have to pretend that mine are beyond reasonable. Never mind that the only difference between us is that I'm twenty pounds overweight and they're fifty pounds overweight. I'm supposed to remember that if my lifestyle were normal, then that would reflect poorly on them, so we have to pretend that their lifestyle is just one or two small tweaks away from being totally healthy, and my lifestyle is the product of an eccentric, overenthusiastic, probably unhealthy interest in fitness. What? I'm still freakin' twenty pounds overweight!

I'm not trying to be a freak. I'm just trying to be NORMAL, trying to live a lifestyle within the bounds my body is engineered to tolerate. I'm just trying not to eat so much food that it harms me. I'm trying not to live a lifestyle so sedentary that my body doesn't know how to cope with it. That's all.

I now bike about 50 miles per week and my appetite is enormous. I start getting hungry about 3 hours after eating, and if I have lunch at 12:30 I can actively seeking food around 5:00, walking to other buildings just to get a handful of chips, i.e. I don't eat just because it's there. I'm also pretty tired in the evenings after the ride sometimes. I sometimes wonder if it's worth it.