While you can lose weight without exercise, regular physical activity plus calorie restriction can help give you the weight-loss edge. Exercise can help burn off the excess calories you can't cut through diet alone.
Exercise also offers numerous health benefits, including boosting your mood, strengthening your cardiovascular system and reducing your blood pressure. Exercise can also help in maintaining weight loss. Studies show that people who maintain their weight loss over the long term get regular physical activity.
How many calories you burn depends on the frequency, duration and intensity of your activities. One of the best ways to lose body fat is through steady aerobic exercise — such as brisk walking — for at least 30 minutes most days of the week. Some people may require more physical activity than this to lose weight and maintain that weight loss.
Any extra movement helps burn calories. Think about ways you can increase your physical activity throughout the day if you can't fit in formal exercise on a given day. For example, make several trips up and down stairs instead of using the elevator, or park at the far end of the lot when shopping.