Truths and Myths About Metabolism

Have you ever heard someone say, “I just have a really fast metabolism”? This comment is usually spoken by someone who seems to have the superpower to eat all of the snacks they want without any major impact on their waistline. (You know those people).

foods that increase metabolism

This comment may leave many of us thinking “Do I have a low metabolism?” or “Are there certain foods that increase metabolism?” Perhaps you even think, “Do I need a metabolism booster?” I’m here to tell the truth about all things metabolism, while debunking some of the most common myths surrounding metabolism.

What is metabolism?

Before we start discussing high metabolism, low metabolism, fast metabolism, and slow metabolism, let’s first tackle the question, “What is metabolism?” According to Harvard Health, metabolism is the internal process by which the body burns calories and expends energy. Whether we are catching zzz’s and resting, working out at the gym, or working at the office, our metabolism is always at work.

Metabolism converts the food and nutrients we eat into energy so our bodies can do things like breathe, circulate blood, grow and repair cells and basically everything in between. Oh you know, nothing major or anything, just basic survival. 

Now that we have established what metabolism is, let’s sift through facts and fiction, metabolism edition.

Metabolism Myth #1: People have a high metabolism or a low metabolism.


Regardless of body composition, shape, or size, people can have an average metabolism, a fast metabolism, or low metabolism. As noted by Harvard Health, metabolism works at different intensities for different people. Like with most things, a high metabolism or a low metabolism is determined mostly by an individual’s genes.

Not sure if you have a fast or slow metabolism? Consider how you gain or lose weight.

According to that same Harvard Health article, “Differences in metabolism speed are evident in how easy or hard it is for people to gain or lose weight. A slow metabolism burns fewer calories, which means more gets stored as fat in the body. A fast metabolism burns calories at a quicker rate, which explains why some people can eat a lot and not gain extra pounds.”

Metabolism Myth #2: Age affects metabolism.


Age affects metabolism even if we start off with a fast metabolism. It is true that our metabolism is slower than when we were kids, but many people can attribute weight gain, especially midlife weight gain, to an inactive lifestyle and poor diet choices. It is not necessarily metabolism alone that affects midlife weight gain though. Things like career, families, and other adult obligations cause many of us to move less, causing a gain in fat and a loss of muscle as we age.

Adults also have a tendency to ignore their natural appetite cues. For example, younger people tend to eat less after having consumed a larger meal. On the other hand, this feeling may fade in adults who tend to eat the same amount of food no matter the size of their last meal.

Metabolism Myth #3: Having more muscle increases metabolism because muscle burns more calories.


Many of us may have heard that more muscle burns more calories thereby giving the body a metabolism booster and this is true. Zoë Schroeder, a registered dietitian with an MS in Sports Nutrition and a Certified Strength and Conditioning Specialist shares more truth of this common metabolism misconception.

“Having more muscle helps you burn more calories at rest than if you had more fat. You can also boost your metabolism by exercising, specifically [participating in] resistance and high-intensity interval training, regularly.” Schroeder also warns us to be aware of beverages, foods, or products that claim to be metabolism boosters, but especially foods, which leads us to our next metabolism myth.

Metabolism Myth #4: There are certain foods that increase metabolism.

Truth and myth.

Although many of us may associate things like cayenne pepper, caffeine, or certain teas to be metabolism boosters, Schroeder tells us otherwise. “Do not be fooled by special metabolism-boosting foods, but instead focus on eating a balanced diet mostly from whole, unprocessed foods, high in vegetables and fruit, lean protein, complex carbohydrates, and healthy fats, and of course lots of water” if you want to boost metabolism. 

Metabolism Myth #5: Eating six small meals a day is more of a metabolism booster than eating three main meals a day.


Many of us have probably heard eating six small meals a day is better for our metabolism than eating three meals a day, but that is a metabolism myth. Jay Cowin, NNCP, RNT, RNC, CHN, CSNA, and ASYSTEM’s Registered Nutritionist and Director of Formulations shares some findings from recent research.

“Researchers compared the effects between eating six meals per day and eating three meals per day with the same calorie count for both sets. No effect on 24-hour fat oxidation rates was found and an increase in hunger occurred. If smaller meals and snacks leave you [constantly] hungry, this may work against your metabolism.”

When it comes to metabolism, there are some truths and myths. Now you know fact from fiction, hopefully, this clears up any confusion and brings some clarity to your own questions about metabolism, metabolism boosters, and foods that increase metabolism.

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About Ashley Martens

Ashley Martens is a Wellness Writer based in Chicago, Illinois. With a background in a digital marketing coupled with her knowledge of general nutrition and a lifelong passion for all things health, wellness, fitness and nutrition, Ashley offers a healthy alternative to traditional writing. You can learn more Ashley and her writing over at her blog, Three to Five a Day.