Metabolism's Weighty Role
You would give up just about anything to be the same weight you were when you were younger, right? Believe it or not, you need not give up too much. But you do need to make some changes, which may actually be easy to do.
Although metabolism plays a large role in controlling weight, it can't take all the blame. Genetics play a role, too. But genetics are predetermined, and cannot be changed. Lifestyle is not predetermined and can be modified.
Metabolism is the amount of energy — in this case, calories — that the body burns to maintain itself. You're always burning calories, even when you're sleeping. Your basal metabolic rate (BMR) is the number of calories your body uses at rest. How many calories you burn depends on your BMR, exercise, and the body's muscle-to-fat ratio. Muscle cells burn more calories than fat cells. Muscular people, with less body fat, have a higher metabolism. Everyone's BMR is different. It depends on genetics and other factors.
Changing with age
After the age of 45, it is estimated that the average person loses around 1% of muscle mass per year. To compensate, you may need to become more active than you once were.
Resting metabolic rate (RMR) regulates body weight, body composition, and daily energy needs. Resting metabolic rate decreases with age in women. The terms BMR and RMR are often used interchangeably.
If you eat more calories than you burn, the excess is stored as fat, and weight gain occurs. According to the CDC, a 1-pound weight loss represents about 3,500 calories. For a weight loss of 1 to 2 pounds per week, caloric intake needs to decrease by 500 to 1,000 calories every day, depending on how much exercise you engage in.
To jump-start your metabolism, you must regain and then maintain your muscle mass. The most efficient way to do that is to develop and stick to a regular exercise program.
- Grantham, Paula, RN, BSN
- MMI board-certified, academically affiliated clinician