How Much Does Your Metabolism Slow Down as You Age?

Reviewed by Dan Brennan, MD on October 25, 2021

Metabolism is the process that turns food into energy, so your body can work right. As you get older, your metabolism slows.‌

Why Does Metabolism Slow Down as You Age?

Loss of muscle mass. As you age, you naturally lose muscle mass. As a result, you burn calories at a lower rate. 

Less active. As you get older, you may get less physical activity than you used to. Not getting enough exercise can lead to weight gain and cardiovascular disease. These conditions also contribute to the slowing of your metabolism.

Gender and genes. These also play a role in your metabolism rate. Men typically have a faster metabolism because they have more muscle mass, heavier bones, and less body fat.

Genes determine your muscle size and ability to grow muscles. These affect your metabolism, too. The less amount of muscle mass you have, the slower your metabolism becomes.  

When Does Your Metabolism Slow Down?

At 30. By this age, you may notice that losing weight isn’t as easy as it used to be. This happens because as you get older, you move less. If you aren’t physically active, you could lose 3% to 5% of muscle mass each decade. 

At 40. Your body starts to lose muscle mass naturally. This process is called sarcopenia. Even if you’re active, your body will still lose some muscle. During this time, fat will start to form instead of muscle. This also slows down your metabolism, depending on how much muscle mass you’ve lost. 

Other factors. Hormones and genetics will also impact how quickly your metabolism slows down as you get older. Every person has a different mix of these, so it can be hard to predict the rate of your metabolism slowing.  

Can Lifestyle Changes Help?

Healthy habits like these are good for your metabolism:

Strength training. Building muscle mass by lifting weights helps you burn more calories when you’re at rest. More muscle mass leads to a higher metabolism.

Aerobic exercise. This also helps you burn calories. Some types of aerobic exercises are walking, running, cycling, swimming, and hiking. Doctors recommended that you get at least 30 minutes of exercise, 5 days a week. Choose aerobic exercises you enjoy so you’ll keep doing them. If you’re struggling to begin, you can break each activity session into 10-minute segments. 

Balanced diet. Fueling your body with breakfast, lean protein, and filling foods will satisfy you longer. It will also speed up your metabolism by boosting your overall muscle mass.

Drink plenty of liquids. Getting enough water is crucial for your metabolism. Drinking green tea has also been linked to boosting your metabolism. 

When to See Your Doctor

Weight gain can be frustrating, especially if you think your slow metabolism is to blame. Unsure where to begin? Having trouble finding the right way to speed up your metabolism? Talk to your doctor. 

They can figure out if you have an underlying condition that’s affecting your metabolism and weight. An underactive thyroid (hypothyroidism), Cushing syndrome, or polycystic ovary syndrome (PCOS) may cause slow metabolism.

Your doctor will diagnose the problem and help you find the best treatment for your age and body. ‌If you’re gaining a steady amount of weight as you get older, you could be at risk for obesity. When your metabolism slows and your weight increases, you can have other health problems. 

It’s important to be mindful of your weight gain and other things that may harm your overall health. You should see your doctor before your weight gain becomes hard to manage.

Show Sources


Aurora Health Care: “8 Metabolism Myths Debunked.”

Japanese Journal of Geriatrics: “Aging, basal metabolic rate, and nutrition.”

Journal of Medical Internet Research: “Effects of a Web-Based Intervention on Physical Activity and Metabolism in Older Adults: Randomized Controlled Trial.”

Mayo Clinic: “Is a slow metabolism the reason I’m overweight?”

NHS: “How can I speed up my metabolism?”

Salt Lake Regional Medical Center: “How Your Metabolism Changes as You Age.

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