Does Your Metabolism Slow Down as You Age? New Research Has the Verdict

aging and metabolism

New research suggests that your metabolism doesn’t slow down as you age.

The human body needs energy at all times, even when you are at rest. Simple processes like breathing and blood flow require your body to use energy to keep them working. Metabolism is the process your body uses to change the food and drink you take into energy. It does this by mixing the calories in your food intake with oxygen. Many believe that the older you get, the more your metabolism slows down. You’ve probably heard a person or two mention how they’ve found it harder to lose weight once getting older. The culprit, they believe, is a slower metabolism. But are they right? Does your metabolism slow down as you age? Well, the findings from this new research might shock you and them. 

Does Your Metabolism Slow Down as You Age?

metabolism and aging

Your metabolism never stops, as your body needs it for breathing, circulation, food digestion, cell growth, repair, etc. When your body is resting, the amount of calories required to function is called your basal metabolic rate (BMR). This value differs from person to person and can account for as high as 70% of your body’s energy.

Your muscle mass mainly influences your basal metabolic rate. If you are bigger and have more muscles, your body will burn more calories, even at rest. This is also at play with the different sexes. Men tend to have more muscle and body fat than women of the same weight and age and burn more calories.

Metabolism is essential in weight loss and bodybuilding because it affects the number of calories you burn daily. To stay on top of things, you must know how much energy you use to determine how many calories you consume to stay healthy. People’s total energy expenditure (TEE) is the total energy consumed daily (1).

Your total energy expenditure in a day combines your BMR, the energy you use for physical activity, and the energy you use to digest food. Your body uses about 10% of the calories that you eat for digestion, absorption of nutrients, moving them, and storage. You must keep this value the same.

Physical activity also affects your total energy use, which is why weightlifting and exercise work. You also have daily non-exercise activities (known as NEAT) like walking around your house, doing housework, or even fidgeting. Of the three combinations to your total energy expenditure, physical activity is the one factor that you can adjust to change a lot.

Common Misconceptions About Metabolism

Metabolism is vital in the amount of energy you use during the day. As a result, there are a lot of myths concerning it, especially when it comes to weight loss. Below are some common misconceptions about metabolism that you might have heard.

Thin People Have Faster Metabolism

Almost everyone knows that thin person that eats so much and never seems to add weight. So people naturally assume that thin people have a higher metabolism. But, unfortunately, this isn’t true; it’s the opposite in most cases, and thinner people have slower BMR.

Plus, as we mentioned earlier, the number of calories that you burn is affected by your muscles. So larger people with more muscles could have a higher BMR. This is why boosting your strength training could help you lose weight faster than just dieting

Eating Carbs First Thing in the Morning Burns Right Them Up

aging and metabolism

The people who say this often point to how cereals, pancakes, and other breakfast foods are usually full of carbs. This doesn’t, however, mean that eating them first thing in the morning is the answer. Instead, the most optimal time to eat carbs and proteins is post-workout.

A Slower Metabolism Means Difficulty With Fitness

You do not have to starve to stay fit because your metabolism is slower. The key is eating healthy foods and focusing on exercise and strength training. Picture it as arming your metabolism with the suitable raw materials that it needs to serve you. We’re talking healthy fat, whole food carbs, vitamins, minerals, and the protein needed to promote the building of lean muscle (2)

Eating Just Before Bed Means Your Food Will Be Converted to Fat

While you may not need the extra calories from that bedtime snack you crave, time isn’t the problem. What’s important is the type of food you go for. Eating fewer calories overall and going for healthy options like fruits or vegetables will not lead to weight gain. 

Your Metabolism Slows Down Once You Hit 30

Ah yes, the bane of many people’s existence, turning 30. While aging does affect metabolism, that is because people lose muscles which we’ve already established leads to a faster BMR. So turning 30 is not why your metabolism slowed and you started adding weight. In fact, the study we’re discussing here says that this doesn’t happen at 30!  

Metabolism and Age What New Research Says

New extensive research shows that your metabolism doesn’t slow down gradually as you get older. On the contrary, it does so only slightly and when you’re much older than 30. This research on 6421 people showed that your metabolism increases from age 1 and peaks at age 20. It then remains stable from ages 20 to 60 regardless of factors like sex and even pregnancy. After 60, the study found that metabolism reduced by only 0.7% per year (3)

So what does this mean? Well, for one, you can stop blaming your metabolism for your weight gain. Achieving and maintaining a healthy weight depends on eating healthy, resting well, and having an active lifestyle. 

The results of this study also support what we’ve always preached – bodybuilders who want to increase their lean body mass should include strength training to the above to see results. 

Final Words

This new research allows weight loss enthusiasts, bodybuilders, and athletes to better focus on the necessary details. Your metabolism doesn’t slow down as you age and cause you problems with weight. The things to control are your calorie intake, the type of food you take to get it, and your amount of physical activity, exercise, and training. 

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  1. Shetty P. (2005). Energy requirements of adults. Public health nutrition, 8(7A), 994–1009.
  2. Wu G. (2016). Dietary protein intake and human health. Food & function, 7(3), 1251–1265.
  3. Pontzer, H., Yamada, Y., Sagayama, H., Ainslie, P. N., Andersen, L. F., Anderson, L. J., Arab, L., Baddou, I., Bedu-Addo, K., Blaak, E. E., Blanc, S., Bonomi, A. G., Bouten, C. V. C., Bovet, P., Buchowski, M. S., Butte, N. F., Camps, S. G., Close, G. L., Cooper, J. A., … IAEA DLW Database Consortium (2021). Daily energy expenditure through the human life course. Science, 373, 808– 812.
Terry Ramos
As a personal trainer and writer, Terry loves changing lives through coaching and the written word. Terry has a B.S. in Kinesiology and is an ACSM Certified Personal Trainer and ISSA Certified Strength and Conditioning Specialist. He enjoys playing music, reading, and watching films when he's not writing or training.