Weight loss isn’t a linear event over time. When you cut calories, you may drop weight for the first few weeks, for example, and then something changes. You eat the same number of calories but you lose less weight or no weight at all. That’s because when you lose weight you’re losing water and lean tissue as well as fat, your metabolism slows, and your body changes in other ways. So, in order to continue dropping weight each week, you need to continue cutting calories.
Be choosy about carbs. You can decide which ones you eat, and how much. Look for those that are low on the glycemic index (for instance, asparagus is lower on the glycemic index than a potato) or lower in carbs per serving than others. Whole grains are better choices than processed items, because processing removes key nutrients such as fiber, iron, and B vitamins. They may be added back, such as in “enriched” bread.
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.