Low-Calorie Sabotage?

Think diet soda helps you lose weight? Think again. According to a study in the International Journal of Obesity, artificially sweetened, low-calorie foods can thwart your ability to regulate how much you eat--if you are a rat, that is. Researchers found that lab animals sometimes fed saccharin-sweetened liquid consumed more food than did rats given an equally sweet but always high-calorie liquid. (Rats given a high-cal supplement the consistency of milk also gained more weight than did rats fed a thicker, pudding-like substance.) The study's authors think the same phenomenon may hold true for humans: early on, we learn to sense how calorie-packed a food is--by its sweetness and viscosity, for example--which automatically keeps us from overindulging. But eating unnaturally sweetened, low-calorie foods may throw our instinct out of whack.