Physical activity and appetite control: can we close the energy gap?

Summary Appetite control can be effectively investigated within an energy balance framework. When people are sedentary, weight gain is favoured because appetite is poorly regulated, and energy expenditure is low. Consequently, people can exist in a chronic state of positive energy balance. This positive energy balance can be construed as an energy gap. This gap that leads to weight gain and maintains the weight different between overweight and lean people is larger than usually recognised. Physical activity can influence body weight by moving people from a sedentary ‘non‐regulated’ zone into a physiologically ‘regulated zone’, where energy expenditure and energy intake are more in equilibrium. In this regulated zone, physical activity improves the sensitivity of appetite control as well as increasing energy expenditure. The effect on body composition is much more important than an effect on bodyweight. Physical activity can reduce fat mass and waist circumference and increase lean (fat‐free) mass. Other health benefits include a decrease in resting heart rate and blood pressure (systolic and diastolic), an increase in cardiovascular fitness and in mood. Consequently, even though there may be some compensation for the energy expended, people have a better regulated appetite and are healthier.