Of course, the diet advice we'd all love to hear is "Eat more and lose more weight!" But what really works is "Eat more often, and you'll lose more weight." Small, but frequent, meals help keep your metabolism in high gear, and that means you'll burn more calories overall.

"When you put too many hours between meals, your metabolism actually slows down to compensate," says Kimball.

If you then eat a huge meal -- at the same time your metabolism is functioning as if you're starving -- your body wants to hold on to every calorie.

While this won't make much difference on an occasional basis, Kimball says, make it a way of life and it can get harder to lose or maintain weight.

Kimball's advice is borne out by the findings of a study that was presented at the 2005 annual meeting of the American College of Sports Medicine. Researchers from Georgia State University reported that when athletes ate snacks totaling about 250 calories each, three times a day, they had greater energy output then when they didn't snack.

The study also found that snacking helped the athletes eat less at each of their three regular meals. The final result was a higher metabolic rate, a lower caloric intake, and reduction in body fat.