This Is Why Your Metabolism Slows Down With Age — Here's What You Can Do About It

Aging is inevitable, and with it comes a lot of changes to our bodies. One of the biggest changes that takes place deals with our metabolism. Metabolism gets a lot of buzz, especially if you're trying to boost it, but have you ever wondered what happens to your metabolism as you get older? To answer this question, POPSUGAR spoke with Avigdor Arad, PhD, RDN, CDE, director of the Mount Sinai Physiolab.

Before going any further, we want to make sure you understand what your metabolism actually is and why it's important. Your metabolism is a complex process that relates to how your body processes energy from fat, sugar, and protein and how it stores that energy. When people talk about their metabolism, they really mean their metabolic rate — the amount of energy, more commonly known as calories, you burn in a day.

Although it is possible to boost your metabolism, "As you age, you lose muscle and that's the mechanism that seems to explain why there is a reduction in energy expenditure on the metabolic rate," Dr. Arad told POPSUGAR. With age, women will experience a reduction of estrogen (caused by menopause) and men will see a reduction in testosterone, which can lead to a higher fat mass and lower muscle mass.

"As you age, you lose muscle and muscle is a very active tissue. When you have less muscle and more fat, it translates to less energy," Dr. Arad explained. Ultimately, how much your metabolism slows with age "really comes down to how much muscle and how much fat you have," he said.

According to Dr. Arad, people over 65 years old tend to burn up to 30 percent less compared to in their 20s because of a reduction of muscle. To prevent a drastic decrease in your metabolic rate as you age, Dr. Arad recommends doing a combination of cardio and weight training to preserve your muscle mass. Staying active will also ensure you can maintain your independence, it will keep you strong and prevent falling, and it will also preserve your energy expenditure/energy level, he said.

Other ways to speed up your metabolism are by eating more protein and healthy fats because they have a higher thermic effect and it's harder for your body to digest and store them. Dr. Arad also advised reducing your sugar intake because sugar-rich foods have a lower thermic effect and require less energy to process. Finally, as mentioned before, strength training will increase your muscle mass and as a result, your metabolic rate. Here's a four-week weightlifting plan to get you started.