Make sure that you don't get hungry by eating small portions throughout the day at regular intervals. Between your meals, eat a 150-calorie snack to keep your metabolism burning and to stave off hunger. Be sure that you don't eat a fattening snack such as sweets or crisps. When you're hungry, your body conserves calories and slows down your metabolic processes.
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.