So simple, so true, and so overlooked. I eat sweets and chips, and I drink both alcohol and soda (both caloric and non-caloric). My secret? I do all four of those things infrequently and with great modesty.

Portion control is critical, says Julie Barnes, a New York-based clinical psychologist. And dining out (unless they are taking a doggy bag home) is one way Americans give up control over their portions.

MarketWatch: Soda and junk foods are not making you fat.