But if sedentary behavior makes us fat and physical activity prevents it, shouldn't the "exercise explosion" and the "new fitness revolution" have launched and epidemic of leanness rather than coinciding with an epidemic of obesity?

Just as animal research tells us that gluttony and sloth are side effects of a drive to accumulate body fat, it also says that eating in moderation and being physically active (literally, having the energy to exercise) are not evidence of moral rectitude. Rather, they're the metabolic benefits of a body that's programmed to remain lean.

...Why is it, that from the moment you enter medical school to the moment you retire, that the only disorder you will ever diagnosis with a physics book - is obesity? This is biology folks, it's endocrinology, it's physiology - physics has nothing to do with it. The law of thermodynamics is always true, [but] the energy balance equation is irrelevant...

What sets science and the law apart from religion is that nothing is expected to be taken on faith. We're encouraged to ask whether the evidence actually supports what we're being told - or what we grew up believing - and we're allowed to ask whether we're hearing all the evidence or just some small prejudicial part of it. If our beliefs aren't supported by the evidence, then we're encouraged to alter our beliefs.

...Why is it that from the moment you enter medical school to the moment you retire, the only disorder that you will ever diagnose with a physics textbook is obesity? This is biology folks, it's endocrinology, it's physiology - physics has nothing to do with it. The laws of thermodynamics are always true, the energy balance equation is irrelevant...

The simple answer as to why we get fat is that carbohydrates make us so; protein and fat do not

The point to keep in mind is that you don't lose fat because you cut calories; you lose fat because you cut out the foods that make you fat-the carbohydrates.

The simplest way to look at all these associations, between obesity, heart disease, type 2 diabetes, metabolic syndrome, cancer, and Alzheimer's (not to mention the other the conditions that also associate with obesity and diabetes, such as gout, asthma, and fatty liver disease), is that what makes us fat - the quality and quantity of carbohydrates we consume - also makes us sick.

We don't get fat because we overeat; we overeat because we're getting fat