Diet and exercise go hand in hand for a healthy body. However, researchers have recently gone so far as to determine when diet and exercise are most important in the weight loss process.
The key to weight loss is to consume fewer calories than you burn. That deficit needs to be between 500 and 1000 calories per day. For most people, it is easier to decrease calories consumed than it is to increase calories burned to that great an extent. This is why cutting calories through diet is often most effective for weight loss. However, doing both, cutting calories through diet and exercise, can give you a weight loss advantage. Exercise will help you burn more calories than diet alone. This New York Times article illustrates the importance of diet in weight loss.
Studies also show that exercise was the most important component in weight maintenance after weight loss. People who lost weight and were successful in keeping it off long-term were those who got regular physical activity.
If weight loss is one of your goals, make sure that a proper diet accompanies your physical activities and exercise. Without diet, you will still reap the many other health benefits of exercise, improved body composition, increased longevity, decreased risk of diabetes, decreased incidence of high blood pressure, decreased depression, etc. Weight loss, however, may be elusive.