Exercise more, eat less.
It sounds so easy. Both of those formulas are foolproof. Anyone who follows them will lose weight, baring some kind of medical problem. Then why is it so hard to keep that old waistline where it's supposed to be?
Because eating, many scientists contend, isn't just about eating. In fact, according to researchers at the University of Toronto, our biological needs have little to do with how much we eat. They've even come up with a name for it.
"Eating occurs within what we have termed a zone of biological indifference, in which the individual is neither genuinely hungry nor genuinely sated," says psychology professor Peter Herman. Environmental cues, not biological mechanisms, are a big part of how much and what we eat: http://abcnews.go.com/Technology/DyeHard/story?id=2671027&page=1&technology=true.