Lose weight while you sleep: it's the classic shady diet supplement pitch. But a recent Dutch study suggests that you could boost your metabolism and burn more calories around the clock simply by eating more lean protein. The study's participants, all women who were already at a healthy weight, found that increasing their protein intake to 30% of their daily calories enabled them to feel more satisfied and less hungry while consuming fewer calories than they would on a more typical diet consisting of about 10% protein.