Have Protein at Every Meal and Snack. Adding a source of lean or low-fat protein to each meal and snack will help keep you feeling full longer so you're less likely to overeat. Try low-fat yogurt, small portion of nuts, peanut butter, eggs, beans, or lean meats. Experts also recommend eating small, frequent meals and snacks (every 3-4 hours), to keep your blood sugar levels steady and to avoid overindulging.
In a way, moderate-intensity physical activity is that "magic pill" a lot of people are looking for, because the health benefits go beyond keeping your waistline trim: Not only can it reduce your risk of cancer, stroke, diabetes and heart attacks, but studies have shown that physical activity can significantly improve the moods of patients with major depressive disorders.