Energy balance

Regular aerobic exercise attenuates the metabolic drive to regain weight after long-term weight loss by reducing the energy gap between appetite and expenditure and blunting the shift in fuel utilization that favors rapid weight regain.

If you have lost weight, simply maintaining a lower calorie intake is often not enough to prevent regain because your body biologically fights back by increasing hunger and efficiency. Regular aerobic exercise (like brisk walking or jogging) helps counteract these biological changes by reducing the drive to overeat and improving how your body uses fuel, thereby helping you maintain your new weight more easily.