Debunked: 5 Major Metabolism Myths

Heart health
Health Articles
June 15, 2021

Get to grips with the science behind some of the most egregious metabolism myths.

If you have been spending your late nights googling “Does green tea boost metabolism?” it probably means you will do anything to try and add some fizz to your metabolism. But be careful—there are tons of crazy theories floating around, many of which are based on decidedly wonky science. Does spicy food speed up metabolism? What about cold showers? Before you start switching up your diet or exercise regimen, or freezing your bits and pieces off each morning, it might be worth taking some time to find out what’s really going on behind the headlines.

Myth 1: Green tea boosts metabolism

If you do google green tea, you’ll find a litany of reported health benefits. One of the main claims is that you can boost your metabolism—and therefore lose weight—by drinking green tea. So, does green tea boost metabolism? Technically, the answer is yes. Green tea has what is called a thermogenic effect, causing the body to burn slightly more calories due to the production of heat. However, this effect is extremely minimal, so much so that it will not make a noticeable difference to your metabolism and caloric burn.

Myth 2: Spicy food spices up your metabolic rate

This is a popular claim all over the internet, but you may want to keep reading before you dump hot sauce all over your next meal. Does spicy food speed up metabolism? Like green tea, eating spicy foods will add only a slight and temporary increase to your metabolic rate due to its thermogenic effect. This increase is so small that it will not make a noticeable difference. Plus, it’s important to remember that spicy foods may irritate your stomach lining. Ever hear of gastritis? It’s not fun and can lead to other health issues. Be sure to eat with caution!

Myth 3: Cold showers make waves with your metabolism

There’s a common myth suggesting that when your body is exposed to the cold—as in a cold shower—a biological mechanism that burns fat by producing heat is engaged, thereby speeding up your metabolism. So, is there any truth to the theory?
A study conducted by the Journal of Clinical Investigation suggested that the effect was minimal and not a realistic weight-loss method. The study, held over the course of 6 weeks, had participants take 66°F showers every day for 2 hours. Most participants lost only 1 or 2 pounds by the end of the study. So, unless you are willing to take 2 hours of cold showers every day in the pursuit of a relatively minor weight loss, maybe save yourself the torture and enjoy a nice warm shower.

Myth 4: Lemon water + morning = healthy metabolism

You may have heard that the best way to start your morning and jumpstart your metabolism is to drink a warm glass of lemon water first thing in the morning. But is there any truth to this? Well, it seems like this is a bit of a myth as well. There are no fat-burning properties in lemon water, and it hasn’t been proven to increase the rate of a person’s metabolism. While lemon water may not increase metabolic rates, it remains a great way to hydrate and get in some extra vitamin C. So if you like the taste, feel free to keep drinking!

Myth 5: It’s better to eat smaller, more frequent meals

The frequency and size of meals is a hot topic, with debates around intermittent fasting and the 5:2 diet attracting a whole host of supporters and detractors. So, what’s the impact of meal size and frequency on metabolism? Is there really an optimal number of times to eat in a day, and does having smaller and more frequent meals speed up metabolism?
While we eat, our bodies burn calories. On average, the number of calories we burn is roughly equal to 10% of our overall caloric intake. This is known as the thermal effect of food (TEF). Your body burns roughly the same number of calories, regardless of the amount of meals you consume in a day. Whether you eat six times a day or three times a day, an average of 10% of those calories will be burned through digestion. So, don’t feel the need to split your meals into smaller portions during the day, as it isn’t likely to have much of an impact on your metabolism.
Okay, so if these are all myths, now what? Are there any real ways to boost your metabolism? Well, we’ll direct you to our article all about the (legitimate) methods that you can use to boost your metabolism. Bottom line? Regular exercise, quality sleep, and a good diet are key, and now we’ll stop writing so you can go for a long walk, take a nap, or prepare a fabulously healthy meal.