Weight loss experts are constantly telling you to burn more calories than you eat in order to lose weight. So how, exactly, do you “burn calories”? Find out what you can – and can’t – do to burn more calories.
Your body burns calories in three ways: metabolism, thermogenesis, and physical activity.
Metabolism is the process by which your body converts what you eat and drink into the energy it needs to function. It’s often said that your metabolism is how many calories you burn when you’re “at rest,” because your body is always using energy for things like breathing, circulation, and cell repair. Your basal metabolic rate—or how many calories your body burns through the process of metabolism—is a naturally regulated function and is fairly difficult to change. Your basal metabolic rate is determined by your sex, age, and your body size and composition. The larger your body is and the more muscle mass you have, the higher your metabolic rate will be. Women, who tend to have less muscle and more body fat, usually have a lower metabolic rate than men. Older people, who tend to have less muscle mass than younger people, usually notice their metabolic rate slows down as they age.
In rare cases, a medical disorder may result in an abnormally low metabolism that can cause weight gain.
Thermogenesis involves the process of digesting, absorbing, transporting, and storing the food you eat. About 10% of the calories your body burns each day are a result of thermogenesis. In most cases, the amount of energy and calories that your body needs for food processing will remain steady and is not easily changed.
The rest of the calories your body burns are a result of physical activity. Everything you do, from fidgeting to walking or running, burns calories. The more physical activity you engage in, the more calories you’ll burn. Unlike metabolism and thermogenesis, you can easily increase how many calories you burn through physical activity if you’re looking to lose weight or maintain your existing weight.