We hear a lot about metabolism, and we often blame a “slow metabolism” for our inability to keep our weight under control. Find out what factors affect your metabolic rate and what you can do to change it.

Do you feel like you have a “slow metabolism” or that your body burns calories at a slower pace than others? You’re not alone! Many people think that if they could speed up the process, their weight problems would be solved. But what is metabolism, exactly? And, more importantly, is there anything you can do to change it?

Metabolism vs. Metabolic Rate: What’s the Difference? 

The words metabolism and metabolic rate are often used interchangeably, but they aren’t the same. Metabolism refers to all the chemical processes that your body undergoes every day to keep you alive. When your body converts the calories in your food into energy, or manufactures specialized chemicals that your cells need in order to do their job, those are metabolic processes. These hundreds of processes your body performs every day make up your metabolism.

The term metabolic rate could be confusing to people. When you hear the word “rate,” you might think “speed” or “tempo.” So, it’s reasonable to assume that metabolic rate can only mean how fast (or slow) your body performs its work.

However, your metabolic rate or, more accurately, your resting metabolic rate, refers to the number of calories you burn during a 24-hour period to keep your body’s most basic processes going. These are processes like pumping blood or breathing.

These aren’t all the calories you burn in a day, but your resting metabolic rate accounts for about 75% of total calories you use up every day. The remaining calories get used up during your daily activities and exercise.

5 Factors that Influence Metabolic Rate

Some people’s bodies use up more calories to perform these basic metabolic processes than others. You might think they have a “fast” metabolism. And for those who seem to require very few calories, you might think their metabolism is “slow.” But now that you know that your metabolic rate isn’t about how quickly you burn calories (it’s really the number of calories you burn each day), you can’t technically make your body burn calories any faster. 

Let’s look at what affects your metabolic rate in the first place. It will give you a better sense of what you can and can’t do to change it.

1. Body size
   Larger people have higher metabolic rates than smaller people do. This is because they have more cells, each of which is doing some metabolic work.

2. Body composition
   A very important factor in determining your metabolic rate is lean body mass or the total weight of your body, including your bones, fluids, organs and muscles, minus your fat mass. Every pound of lean muscle mass burns about 14 calories per day, or about 30 calories per kilogram. A pound of fat only burns about two. Unlike fat cells, muscle cells have a lot more machinery to convert calories into energy. So, it makes sense that as your muscle mass increases so would your metabolic rate, since, metabolically speaking, your muscle cells are very active.

3. Age
   As you age, there is a tendency to lose some muscle mass. There are a couple of reasons this happens. For one thing, natural hormonal changes can contribute to some loss of muscle mass. And the muscle damage that results from everyday wear and tear isn’t repaired quite as quickly as you age. That can contribute to some muscle loss, too. With fewer muscle cells overall, you can’t help but burn fewer calories over the course of the day.

4. Gender
   Men have higher metabolic rates than women do for two simple reasons: They tend to have bigger bodies and more muscle mass.

5. Cutting your calorie intake too much
   When you cut your calorie intake too much your metabolic rate can take a dip. This makes sense if you think about it. Your body is just trying to do the same metabolic work with fewer calories to keep you alive. In general, these decreases are relatively small, especially if you make modest – rather than dramatic – decreases in your calorie intake as you attempt to lose.

3 Ways to Boost Your Metabolic Rate

Now that you know what factors affect your metabolic rate, what can you do about it?

1. Eat enough protein.
   Your body uses the protein you eat to build and repair muscle tissue. If you don’t consume enough protein in your diet, your body simply doesn’t have the raw materials it needs to manufacture and repair your muscle cells.

2. Build muscle mass.
   This is probably one of the most important things you can do, since building muscle will increase the amount of lean body mass you have, which increases your overall resting metabolic rate. And don’t think strength training is only for the younger set. With the right diet and proper exercise, your body is capable of building muscle at any age.

3. Increase your daily activity.
   Any activity burns calories, but that doesn’t affect your metabolic rate. When you exercise, you are using your muscles to move your body, and that helps to preserve your lean body mass. Increasing your activity may also help offset any dips in your metabolic rate from cutting your calorie intake.