Ok, I just KNOW someone is going to insist, despite what I write, that low fat diets are the culprit.

The mental contortions one has to go through to believe this are stunning, but Robert, you wrote the very very simple response to this that I believe is indisputable:

". Most adults should consume somewhere between 1,600 and 3,000 calories a day (here’s a calculator for you).But let’s not kid around: Most of us eat more than we need. The average American takes in more than 3,600 calories daily, 24% more than in 1961 — even though we’re much less active nowadays."

Why do we weigh more? We're eating more than we need. Wow, THAT was complicated to figure out!!

(and I'll add, I think the reason people don't want to believe this is primarily emotional - nobody wants to take responsibility; they'd rather blame carbs, low fat diets, chemicals, drugs, genes - no, you ARE responsible for what you eat and you CAN learn to change your habits.