Which is better for weight loss — cutting calories or increasing exercise?
Cutting calories through dietary changes seems to promote weight loss more effectively than does exercise and physical activity.
The key to weight loss is to consume fewer calories than you burn. For most people, it's possible to lower their calorie intake to a greater degree than it is to burn more calories through increased exercise. That's why cutting calories through dieting is generally more effective for weight loss. But doing both — cutting calories through diet and burning calories through exercise — can help give you the weight-loss edge. Exercise is also important because it can help you maintain your weight loss. Studies show that people who lose weight and keep it off over the long term get regular physical activity. If you lose weight by crash dieting or by drastically restricting yourself to 400 to 800 calories a day, you're more likely to regain weight quickly, often within six months after you stop dieting. Getting regular exercise can also help prevent excess weight gain in the first place.