Well duh! Obviously if a person chooses to modify their food intake radically without increasing overall exercise levels then of course they'll ultimately gain weight.

The problem isn't JUST food intake, its a combination of lifestyle, exercise, diet, as well as inherent metabolic rates. No one can control the metabolic rates directly, but the other 3 are perfectly adjustable.

Its a flawed belief to think that everyone can be physically fit, we don't all have the same motivations, lifestyles, nor do our bodies work the same way. Some people are more adept at burning calories naturally, some just can't seem to shed weight no matter what they do. I think its important that people recognize that fat people aren't necessarily gluttons - an accusation I've heard quite often in Human Nature. But what I believe fat people need is therapy - the same kind of therapy given to bulemics, anorexics, and other people suffering from eating disorders. But more importantly I think they need simple understanding from the people around them - not bigotry, condescension, or quick fixes - like diets.

Fat people have slower metabolisms than leaner people even if they are eating smaller portions than everybody else. Some of this is due to insufficient activity levels to keep the calories burning. Lowering calorie intake over the long term causes a body to go into conservation mode & try to convert any extra calorie to fat. Long term dieting is self defeating if the goal is keeping the fat off. Dieting works fine if a temporary weight loss is all you're wanting to achieve with it.

You've read about the study in which people trying to gain weight had to eat an absurdly large number of calories daily to do so, and almost immediately lost the weight. And people trying to lose weight almost immediately plateau'ed despite very decreased caloric intake.

What happened was, thin people's metabolism speeded up to burn the calories while heavier people's metabolism slowed down to preserve the fat.

If you can't control the metabolism, you can't control the weight.

Not necessarily true. But the means of getting there may be outside the realm of a normal person's will.

I highly doubt that anyone a few million years ago was fat, obesity is a consequence of our conquest of the environment around us.

Metabolic rates do play a part, indeed, and that defines thr differences between us as individuals. However, when discussing the common thread for all of us, the problem with the now frequent observation about diets not helping - and indeed sometimes making things worse - lies in the wrong perception.

It is common knowledge that all conventional diets revolve around food rationing and/or selection. The thing is, the ratio "energy absorbed vs energy spent" holding true, food is not the primary factor defining our fitness/weight. Food (or calories, if you wish) is a distant third, after drinks being second. The primary factor is in fact a combination of "behavioral factors".

Once you allow for that theory, every single observation (like those in discussion here) becomes easy to explain. That theory is launched by an European fellow, with more details in a book called "My Diet", see www.dukaty.com, under "Publishing". As long as most people (the Americans in particular) keep swearing in calorie counting, BMI and other food-focused "miracles", obesity will keep mounting, and diets will keep not working.

While I don't believe that everyone can be Venus Williams (or any other super fit person you can think of), I believe that most folks can make more of an effort to eat healthier and exercise more. Life isn't fair and some of us are wired to have faster metabolism than others. My own personal experience and what I've observed from watching others tells me that people regain weight because they allow themselves to fall off the wagon-- perhaps only a little bit at first; but then they throw in the towel and revert quickly to old habits. Healthy lifestyle changes can't be temporary gimmicks- they have to be permanent. And some of us have to work at it harder than others. Again, LIFE IS'T FAIR.

I know and love some large folks, and I grew up wearing clothes from Lane Bryant myself. Unfortunately, the large folks that I know have not been able to make any permanent changes. I have a wonderful friend that I love very much who lost 55 pounds last year before she simply 'gave up' after a month long plateau. She's back to her old eating habits, and she has regained most of the weight she lost- But this happened because she quit eating sensibly, and stopped exercsing, not because she is destined to be fat no matter what. Worst of all, she is raising her 4 year old child with the same terrible eating habits. I see her daughter waddle and huff and puff when she tries to run.

As a former chubby kid, it breaks my heart to see people treated cruelly because they are fat. But I think it is more troubling to see people just give up and revert back into habits that are unhealthy.