I was using it to mean "arbitrarily much food". My position is similar: If you eat just until you're full and you get moderate exercise but you're still overweight, you should talk to your doctor. You may still need to change your eating or exercising habits, but you should do research first, and not make any sweeping changes all at once.

Changing your habits is always difficult, and that's where the willpower comes in. It should only be needed until you settle into your new habits, though. And you should never have to be constantly hungry, or end up having to eat almost nothing, as Janet said. Both outcomes are extremely unhealthy.

I think I'll add this to my original post to clarify my position. I seem to have come across as more extreme than I intended.

Caloric expenditure is not strictly a function of behavior. Holding all else constant, including amount of exercise, reducing caloric intake will also reduce expenditure.

I know, this is why when people stop dieting and return to their original level of consumption, they sometimes end up heavier than before, as Janet mentioned. It's usually better to increase exercise rather than decrease calorie intake, but this thread is about diet, so I haven't really gone into that.

Sometimes it will reduce it by more than the reduction in intake.

Not to say it can't, but I've never heard of this happening. Reference, please?

Once again, it seems I've stated my position badly. I really shouldn't have used the word "simple" in my opening post. Nothing in biology is simple.

I'm not trying to say you can cut food willy-nilly and still be healthy. I'm not trying to use energy balance as a curiosity stopper. I'm trying to use it to combat claims that you can eat as much "good" food as you want as long as you avoid "bad" food.

Thanks for pointing out something else I should have clarified in my first post.

I'm not trying to compare the metabolisms of multiple people. Some people can eat a lot more than others and maintain a healthy weight.

All I'm saying is that if a single person wants to lose weight, and they reduce their caloric intake (or increase caloric expenditure) while keeping everything else the same as they were doing before, they will lose weight. And I agree that if the person returns to old habits, they will gradually return to their original weight.

You're right in that I overstated the willpower angle. Possibly the best diet is one that's easy to adhere to, thus reducing the necessary willpower expenditure. I wonder if that's the real reason there's so many different diets out there; some people find it easier to reduce carbohydrates, others fats. Which diet works best may depend on individual food preference more than biochemistry.

I agree with everything you said until you mentioned that sugar is the real cause of people overeating. There are a lot of possible reasons for someone to overeat, and none of them, in my opinion, are solely dietary. The cause may be psychological - for example, a lot of people eat when they're depressed or bored. I myself sometimes succumb to the latter. Some people hate to exercise. Willpower will help in all of those cases.

The only case I can think of where sugar might be considered the culprit is if someone drinks way too many sodas, for example. But the problem isn't the fact that it's sugar in the soda, it's that the person is consuming a lot of extra calories they wouldn't otherwise get. They'd be just as overweight as if they ate a calorically equivalent amount of potato chips. They need the willpower to stop their soda habit.

Regarding nutrient deficiencies, I've only been talking about calories, not other types of nutrients. I apologize for not making this clear in my first post. Obviously, if you need more vitamin C, you're better off drinking some orange juice than a calorically equivalent amount of soda. You should always have a varied diet that contains enough essential vitamins, minerals, and amino acids.

From the New York Times article:

On the one hand, we've been told with almost religious certainty by everyone from the surgeon general on down, and we have come to believe with almost religious certainty, that obesity is caused by the excessive consumption of fat, and that if we eat less fat we will lose weight and live longer.

Either Taubes is throwing out a straw man here, or his opponents are ridiculously simplistic. It's pretty well established that some fat can be good for you, and length of life is based on a whole ton of factors.

The problem with nutritional science is that you don't need any sort of expertise to get a platform, you just need strong opinions. See both Taubes and his opponents. Those kinds are always trying to scare you into buying their latest book by simplistically dividing food into "good" and "bad" types, and insisting you'll die if you keep eating the bad ones. Not to mention lose weight if you eat the good ones.

Weight management boils down to simple physics, namely the First Law of thermodynamics. If you consume less energy while spending more (via exercise mainly), you'll lose weight. One calorie is completely interchangeable with another calorie, it doesn't matter where it came from. (The exception being that it's easier to add muscle mass by eating proteins.)

The hard part about losing weight isn't knowing what to eat, it's having the willpower to eat less (or exercise more). Of course, you can't sell a book by telling everyone "we're fat because we have no willpower". "We're fat because we've been lied to", however, will sell.

(EDIT: I'm going to add some clarifications on my position here because the feedback shows that I've made my position seem more extreme than I intended.

First, I shouldn't have said it was simple, it's not.

If you eat just until you're full and you get moderate exercise but you're still overweight, you should talk to your doctor. You may still need to change your eating or exercising habits, but you should do research first, and not make any sweeping changes all at once. And you should never have to be constantly hungry, or end up having to eat almost nothing. Both outcomes are extremely unhealthy.

Changing your habits is always difficult, and that's where the willpower comes in. It should only be needed until you settle into your new habits, though.

I'm not trying to compare the metabolisms of separate people. Some people can eat a lot more than others and maintain a healthy weight.

I'm not trying to say you can cut food willy-nilly and still be healthy. I'm not trying to use energy balance as a curiosity stopper. I'm trying to use it to combat claims that you can eat as much "good" food as you want as long as you avoid "bad" food.)

China's been using that strategy for a very long time, and it's netted them quite a large expanse of territory. I would argue that China's current powerful position on the world stage is mainly because of that policy.

Of course, if space colonization gets underway relatively soon, then the nibbling strategy is nearing the end of its usefulness. On the other hand, if it take a couple hundred more years the nibbling can still see some real gains, relative to more cooperative countries.

Territorial expansion didn't work for the Nazis because they didn't stop with just Austria and Czechoslovakia. The allies didn't declare war until Germany invaded Poland, and even then they didn't really do anything until France was invaded.

It seems to me that the pluralistic countries aren't willing to risk war with a major power for the sake of a small and distant patch of land (and this goes double if nuclear weapons are potentially involved). They have good reason for their reluctance - the risks aren't worth the rewards, especially over the short term. But an aggressive and patient country can, over long time periods, use this reluctance to their advantage.

For example, there's the Chinese with Tibet and the Russians more recently with South Ossetia.

The USSR also got away with seizing large amounts of land just before and during WWII, mainly because the Allies were too worried about Germany to do anything about it. I concede this was an unusual situation, though, that's unlikely to occur again in the foreseeable future.

(Edited for spelling)

"(and why did it take so long for people to figure out the part about empirical verification)?"

Most of the immediate progress after the advent of empiricism was about engineering more than science. I think the biggest hurdle wasn't lack of understanding of the importance of empirical verification, but lack of understanding of human biases.

Early scientists just assumed that they were either unbiased or that their biases wouldn't affect the data. They had no idea of the power of expectation and selection biases, placebo effects, etc. It wasn't until people realized this and started controlling for it that science took off.

'An important aspect of my proposal will be to expand the definitions of the words "scientific theory" and "scientific method"'

I have to admit that this idea makes me extremely wary, but that's probably because I'm used to statements like this coming from people with a harmful agenda (i.e. creationists). I'll try to keep an open mind when I read your future posts in this series.

Neanderthals were also in the Near East.

http://en.wikipedia.org/wiki/List_of_Neanderthal_sites

You have a point about the cultural explosion, though. Africans don't seem to be less cultural than non-Africans, despite the fact that they don't seem to have any links to Neanderthals. It occurs to me that this lack of a link, after all this time, exemplifies how slow gene sweep is in a population as numerous, long-lived, and spread out as humanity.

Actually, there is genetic evidence now.

http://www.sciencedaily.com/releases/2010/05/100506141549.htm

There are genes lacked by Africans that are shared by Neanderthals and non-Africans. Interbreeding seems the most likely explanation for this pattern.