You've probably heard people blame their weight on a slow metabolism, but what does that mean? Is metabolism really the culprit? And if so, is it possible to rev up your metabolism to burn more calories?
Contrary to common belief, a slow metabolism is rarely the cause of excess weight gain. Although your metabolism influences your body's basic energy needs, it's your food and beverage intake and your physical activity that ultimately determine how much you weigh.
Metabolism: Converting food into energy
Metabolism is the process by which your body converts what you eat and drink into energy. Even when you're at rest, your body needs energy for all its "hidden" functions, such as breathing, circulating blood, adjusting hormone levels, and growing and repairing cells.
The number of calories your body uses to carry out these basic functions is known as your basal metabolic rate — what you might call metabolism. Several factors determine your individual basal metabolic rate, including:
- Your body size and composition. The bodies of people who are larger or have more muscle burn more calories, even at rest.
- Your gender. Men usually have less body fat and more muscle than do women of the same age and weight, burning more calories.
- Your age. As you get older, the amount of muscle tends to decrease and fat accounts for more of your weight, slowing down calorie burning.
In addition to your basal metabolic rate, two other factors determine how many calories your body burns each day: