Overview

Are you tired of the diet-and-exercise approach to losing weight? Do you wish you could take a pill to boost your metabolism and watch the pounds disappear?

As Americans grow stouter, the search for get-thin-quick products continues. But is there really a pill or food out there that can boost your metabolism?

The answer is “Yes,” and “No.” Learn how to separate fact from fiction when it comes to metabolism booster claims.

How does metabolism work?

Simply put, your metabolism is all of the chemical processes that convert carbohydrates, proteins, and fats from your food into the energy that your cells need to function.

Your metabolic rate is the amount of time it takes your body to process and burn energy, or calories, from the food you eat. Your basal metabolic rate (BMR) is the amount of energy, or calories, your body needs to maintain basic functions when you’re resting. It’s how many calories you would need to survive if you never moved.

According to the Mayo Clinic, your BMR accounts for approximately 70 percent of your daily energy use.

Several things influence your BMR:

• Genetics: The Calories you burn per day is largely determined by genetics.
• Age: Your average BMR decreases by 2 percent per decade after age 20.
• Gender: Men tend to have a higher BMR than women.
• Weight: As your weight increases, so does your BMR. 
• Height: Tall people tend to have a BMR than shorter people.
• Body makeup: Your BMR will be higher if you have more muscle and less fat.
• Diet: Long-term low calorie intake can significantly reduce your BMR. So, extreme dieting can actually work against you.

Certain medical disorders, certain medications, and climate can also change your BMR.

How much you move, both in general and with exercise, also reflects the total number of calories you burn. You also burn calories digesting food, a process called diet-induced thermogenesis.

Do metabolism boosters work?

Some companies sell products that supposedly boost your metabolism. Most claim they do this through a process called thermogenesis, or increased heat production. This process stimulates energy use and can increase your metabolism and help burn calories.

Most supplements that claim to raise your metabolism contain a combination of ingredients. Because these ingredients are almost always tested individually, we need to assess them on that basis.

Let’s explore some of the most common ingredients found in products that claim to increase metabolism.

Caffeine

Research has shown that caffeine can increase thermogenesis. According to a review article published in Obesity Reviews, six different studies have found that people burn more calories when they take a minimum daily dose of 270 milligrams (mg) of caffeine.

To put that in perspective, most caffeine supplements contain 200 mg of caffeine, while one cup of coffee contains about 95 mg.  However, if you drink caffeine on a regular basis, this effect might be lessened.

Talk to your doctor before adding more caffeine to your diet. And make sure your caffeine sources aren’t too high in calories. If you drink too many sweetened coffee drinks or chai tea, you could actually find yourself gaining weight!

Capsaicin

Capsaicin is the chemical that puts the hot in jalapeños. There’s some indication it may help promote weight loss. In fact, a review of 20 research studies, published in Appetite, found that capsaicin can increase the amount of calories you burn by approximately 50 calories a day. Those calories can add up over time, contributing to long-term weight loss. So consider spicing it up in your kitchen!

L-carnitine

L-carnitine is a substance that helps your body turn fat into energy. While your body produces it in your liver and kidneys, you can also find it in meat, dairy products, nuts, and legumes.

L-carnitine may be helpful for treating a number of conditions, including heart disease, peripheral artery disease, and diabetic neuropathy. But its use as a dietary supplement for weight loss is questionable.

One study reported in the Journal of Medicinal Food found that L-carnitine might provide some anti-obesity benefits. But more research is needed to assess the benefits and risks of taking L-carnitine supplements for weight loss.

According to the Office of Dietary Supplements, taking too much of it can cause potentially dangerous side effects.

Chromium picolinate

Chromium is a mineral that your body uses in small amounts. Chromium picolinate supplements are useful for people who have a chromium deficiency. But it’s effectiveness as a metabolism booster is questionable.  

So far, researchers have given it a thumbs-down. A pilot study reported in the Journal of Alternative and Complementary Medicine found that chromium picolinate supplements had no effect on weight loss.

Conjugated linoleic acid (CLA)

As with many supplements, research on CLA has found mixed results. A review of studies published in the European Journal of Nutrition found evidence that CLA may promote weight loss and fat loss, but the effects were small and uncertain.

Gastrointestinal problems and fatigue are common side effects of taking CLA supplements, so you may want to pass on this one.

Green tea

Numerous studies have been conducted on the effectiveness of green tea for weight loss. Few have reported significant results.

One study published in Physiology and Behavior does suggest that catechins and caffeine found in green tea may help support weight maintenance. Green tea is considered a safe addition to most people’s diets.

Resveratrol

Resveratrol is a substance found in the skin of red grapes, mulberries, Japanese knotweed, and peanuts. Studies suggest it does burn fat in rats. But according to researchers in the Annals of the New York Academy of Sciences, there’s not enough evidence to support its use as a metabolism booster in humans yet. More clinical trials are needed.

The takeaway

Despite the hype, supplements that are promoted as fat busters and metabolism boosters rarely have a significant effect on weight loss. If you want to shed excess pounds, cutting calories from your diet and exercising more regularly are probably your best bets.

Ask your doctor for more advice on losing weight in safe and sustainable ways. And talk to them before trying any weight loss medications or supplements. It’s best to have your doctor help you assess the potential benefits and risks.

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