How Your Metabolism Changes As You Get Older

It's no secret that your metabolism changes as you get older. Depending on your body type and activity level, you may not be able to eat the same types of food you once did and still maintain the same weight. That's because your metabolism gradually slows down as you age (via Healthline).

There are four elements that ultimately determine the speed of your metabolism: exercise, resting metabolic rate, the thermic effect of food, and non-exercise activity thermogenesis. These key factors measure how many calories you burn from rest, exercise, digestion, and standing and are influenced by your age, height, muscle mass, and hormones. Changes in hormones and muscle mass are often a direct result of getting older.

"There are actual real hormonal changes that take place in our body [as we age] that then affect the way we store fat and lose fat," Kristen F. Gradney, R.D., the director of nutrition and metabolic services at Our Lady of the Lake Regional Medical Center and a spokesperson for the Academy of Nutrition and Dietetics, told Self. "Our metabolic rate actually decreases because of these differences in hormones."

In addition to your hormone levels and muscle mass, your metabolism is also affected by your activity level, which tends to decrease with age. The amount of time you spend exercising and standing can account for nearly 50 percent of the calories you burn (via Healthline). That's why it's important to stay busy and engage in activities that will help you burn more calories if you want to try to prevent your metabolism from slowing down.

Weight lifting can help build muscle mass while also burning calories. One study found that six months of weight lifting can increase the resting metabolic rate of people over the age of 60 by nearly seven percent. High-intensity interval training (HIIT) can also help speed up your metabolism, since it allows you to continue burning calories hours after you've finished exercising. Eating a protein-rich diet and getting plenty of sleep can also help slow down your metabolism's aging process.