Why are active people often less likely to have excess body weight?

Active individuals are often less likely to have excess body weight because of the fundamental law of conservation of energy. Weight management is determined by the balance between energy intake and energy expenditure; when energy intake exceeds expenditure over time, the body stores the excess as fat.1

Physical activity—which includes exercise and other voluntary movements—is the most variable component of daily energy expenditure, accounting for 20 to 40 percent of the total energy used by the body. While a sedentary person may expend significantly less energy, an active individual increases their total daily caloric output, making it easier to maintain an energy balance that prevents the accumulation of excess adipose tissue. Conversely, increasingly sedentary lifestyles, often driven by digital habits and reduced physical movement, have been linked to higher rates of obesity. Engaging in regular physical activity is a vital, common-sense approach to managing weight and improving overall health.12