What Is Metabolism?

Medically Reviewed by Tyler Wheeler, MD on July 20, 2023
3 min read

You might hear people talk about metabolism when discussing health, weight, and nutrition. It can be low, high, slow, or fast, but what does it mean? Metabolism is a series of processes that control how your body creates and uses energy.

Most people think metabolism is all about genetics, things that are passed down from your parents. They believe that some people are just born with a high metabolism, and they can eat whatever they want. But there are several things that you can control that affect your metabolism. 

No matter what you’re doing, your body is always working and using energy. This energy comes from the food and drinks you consume. Your metabolism controls how much of that energy your body uses. 

Metabolism is broken down into two processes: anabolism and catabolism. Anabolism is the storing of energy, supporting new cells, and maintaining body tissues. Catabolism is the opposite, breaking down energy to move, heat, and energize your body.

It’s easy to blame problems with weight on metabolism. But maintaining your weight is a complex process that involves genetics, hormones, diet, lifestyle, sleep, physical activity, and stress.

A lack of activity combined with lower energy needs creates a slow metabolism. Then, if you give your body too much energy in the form of calories, that energy has nowhere to go and is stored as fat. 

Your metabolism is working to maintain your weight. You can’t change your routine for a few days and expect major changes. A balance of good habits will help your metabolism recognize a new ideal weight.

Genes. How much energy your body needs is determined by a handful of genetic factors. Larger people have more muscle mass and usually need more calories. Men tend to have less body fat and more muscle mass, so they need more calories.

A common myth is that age causes your metabolism to slow. But age isn’t the problem. As you get older, you may not be as physically active, you may have less muscle mass, and your diet may not change to suit your body’s needs. All of these things lead to a slower metabolism.

Diet. There are no miracle foods, eating plans, or perfect diets to maintain your metabolism. But you can still improve your metabolism through your diet. A diet of good carbohydrates, a suitable amount of calories, and consistent meals will give your body the energy it needs.

One popular diet to improve metabolism is intermittent fasting. This involves eating during a set number of hours each day (often about 8 hours) and not eating for the rest of the time. When your body burns through the energy it took in, it starts using energy stored in your body’s fat. This may allow your body to clean and get rid of any extra fuel it has lying around.

Intermittent fasting can be helpful for weight loss, heart health, diabetes, and obesity. There are many plans, so it’s important to pick one that works with your own health and needs. Talk with your doctor before trying it.

Sleep. Sleep helps regulate your glucose, or blood sugar. A lack of sleep causes your body to have trouble with glucose levels, leading to a lack of energy.

Good sleep habits don’t involve counting minutes and sleep aids. Make sure you’re getting good sleep by:

  • Going to sleep and waking up at the same times every day
  • Avoiding caffeine, nicotine, and long naps within a few hours before bed
  • Avoiding blue light before bed, such as TVs, computers, and phones

Sleep is a great time for your body to burn extra energy. Boosting your metabolism through diet and exercise will also help your body burn more calories while at rest.

Exercise. An important piece of the puzzle is exercise. Moving your body uses the most energy and burns calories. Regularly moving, even on a walk around the block, boosts your metabolism to help you use excess energy, burn fat, and improve your heart health.

Muscle-strengthening exercises are also important to make sure you have a healthy amount of muscle. More intense strengthening exercises will help reduce the signs of common metabolic diseases.