We’ve all seen the headlines singing the praises of that one fat-melting food that will rev up metabolism or somehow magically melt away extra pounds. While some foods may aid in boosting your metabolism, they won’t likely make a significant difference overall.
That’s not to say foods don’t affect your metabolic system at all. For example, hot peppers and green tea have both been shown to boost metabolism, albeit slightly. We dug into the science to understand the nuances behind those dramatic headlines and serve up some truth about food and metabolism.
Metabolism refers to any bodily process that uses energy, including digestion, breathing, circulation, controlling body temperature, muscle contraction, and brain and nerve function. The body expends a certain number of calories to perform these functions at rest, which is otherwise known as resting metabolic rate.
There’s much debate as to whether your resting metabolic rate is set in stone or can be altered. “In a way, every food will increase metabolism because it needs to be broken down,” says Mascha Davis MPH, RDN, owner of Nomadista Nutrition. “The speed of our metabolism is largely outside of our control and plays only a minor role in weight management,” Davis adds.
Here are some foods that have the potential to moderately or temporarily affect your metabolism.
Many believe that sipping a cup of green tea revs up your metabolism, but that’s only partly true. One older meta-analysis found that drinking green tea in conjunction with reducing calories resulted in weight loss. The researchers attribute this positive impact largely to EGCG, a compound in the tea which is believed to promote fat oxidation.
A 2017 study also suggested that EGCG alone might increase metabolic rate at sufficient doses (~300 milligrams). The study noted that larger trials were needed to fully understand how it affects metabolism.
Adding a cup of green tea full of healthy things like polyphenols to your daily routine sounds like a no-brainer, but the amount used in clinical settings tends to be much higher than an average cuppa. Our take? Drink it if you enjoy it… maybe in latte form?
We’ve all heard the rumors that drinking cayenne and lemon water will crank up your metabolism. That’s probably a little far-fetched, but there’s some evidence that capsaicin (the compound found in hot peppers) may boost metabolism and have other metabolic benefits.
Here’s the caveat: Most studies use a large amount of cayenne pepper in supplement form. A 2017 review of studies found that most benefits in sustained weight loss and fat oxidation were from supplements with higher amounts than you’d eat in typical food.
However, studies have been showing benefits in weight loss from the addition of capsaicin. A 2013 study suggested that a potential benefit of capsaicin is preventing some of the normal decreases in energy expenditure you might see when in a calorie deficit.
According to Davis, meals higher in protein or fiber typically take more energy to digest — meaning they might amp up overall energy expenditure.
A small 2021 study found some connections between a high-protein diet replacement and the promotion of fat loss and energy expenditure more than just a calorie deficit. This doesn’t mean we should all replace our diets with high protein supplements, but rather that protein may have some beneficial effects on the metabolism.
Other studies have suggested that including good amounts of protein (about 35 to 30 grams per meal) may have benefits for appetite, body weight management, and cardiometabolic risk factors.
“Moderate caffeine intake has been shown to temporarily increase an individual’s metabolic rate,” says Kristen Smith, MS, RD. However, she suggests holding off on the extra-large coffee. “Large intakes of caffeine can result in health consequences such as a rapid heart rate, digestive issues, or insomnia,” Smith says. The National Institutes of Health (NIH) recommends less than 400 to 500 milligrams per day for most nonpregnant adults.
She also adds that drinking a ton of coffee may displace other much-needed nutrients from your diet, like protein, fat, carbs, vitamins, and minerals. So while that cuppa joe might be a convenient way to wake up all the systems in the a.m., it shouldn’t be the only thing you put into your body. Plus, watch out for a ton of added sugar which can start to counter those beneficial effects.
Coconut oil’s claim to fame is that it contains medium-chain triglycerides (MCT), which are thought to be stored in the body less easily than other types of saturated fat.
One 2018 study suggested some exercise endurance benefits from increased MCTs. A 2015 meta-analysis suggested some potential for modest reductions in body weight from eating more MCTs than long-chain triglycerides (LCTs), but more research needs to be done to understand long-term effects and the full picture.
Another 2018 study, on the other hand, found no significant changes to energy metabolism when coconut oil was added to a breakfast meal.
Ultimately, we’re not sure if coconut oil is having any major effects on metabolism. If you’re including it for other health reasons, then we’re with you. But all signs point to other foods for more solid evidence of metabolism bonuses.
“Unfortunately, no single food is going to magically boost your metabolism,” Smith says, and the research concurs. “The downside of such claims is that people might rely on the ‘fat-burning’ effect of certain food instead of making sustainable dietary changes,” Mascha adds.
Even though green tea or cayenne pepper may help you burn an extra 20 to 50 calories, neither is likely to make a huge difference in your overall weight. According to the experts, the key to a healthier-for-you weight is eating a balanced diet composed of nutrient-dense foods. Yup — good old balanced eating and moderation come out on top yet again.