Foods That Boost Metabolism: What the Research Shows

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Foods that boost metabolism exist only in a small, measurable sense: protein costs the body more energy to digest than carbohydrate or fat, and eggs, fish and legumes are protein sources, while caffeine, green tea and chili peppers increase energy burn a little in short studies. The NIH Office of Dietary Supplements says in its consumer fact sheet on weight-loss supplements that the proven ways to lose weight are eating healthful foods, cutting calories and being physically active. No food, coffee habit or metabolism trick on this page replaces those three.

I am not a doctor, so this guide sticks to what researchers measured. To see where these foods fit in a day of eating, start with my weight loss meal plan guide and for how whole eating patterns compare, the best diets for women over 40.

Table of Contents

Which foods boost metabolism, and by how much?

Food or compound	What was measured	Size reported	Main limit
Protein	Energy used to digest the food	20 to 30 percent of its calories, versus 5 to 10 for carbohydrate and 0 to 3 for fat	Digestion cost only; weight results are not consistent
Green tea catechins plus caffeine	24-hour energy expenditure	About 4.7 percent higher	Short studies; no meaningful weight loss in longer trials
Caffeine alone	24-hour energy expenditure	About 4.8 percent higher	Short studies; fat oxidation change not significant
Chili pepper capsaicin	Energy expenditure and appetite	About 50 calories a day	NIH says not studied enough to know if it helps weight loss

Does protein boost metabolism?

Yes, in the sense that your body burns some of a protein’s calories just digesting it. A review of how food affects metabolism, called diet-induced thermogenesis, in Nutrition and Metabolism reports values of 0 to 3 percent for fat, 5 to 10 percent for carbohydrate and 20 to 30 percent for protein, and says that on a mixed diet at energy balance it makes up 5 to 15 percent of daily energy expenditure.

A systematic review of randomized studies in the Journal of the American College of Nutrition found convincing evidence that higher protein intake increases thermogenesis and satiety compared with lower protein diets. Higher-protein diets sometimes led to more weight and fat loss, but results were not consistent and longer studies were needed. If you have kidney disease, check with your clinician before increasing protein.

Do green tea and coffee boost metabolism?

In controlled studies, catechin and caffeine mixtures and caffeine on its own raised 24-hour energy burn slightly. Those studies used supplements and mixtures, not cups of coffee.

What does green tea do?

A 2011 meta-analysis in Obesity Reviews pooled six articles that measured energy use in respiration chambers. Catechin and caffeine mixtures increased 24-hour energy expenditure by 428 kilojoules (4.7 percent) and fat oxidation by 12.2 grams (16 percent).

Longer trials measured weight directly, and they look different. A Cochrane review of randomized trials lasting at least 12 weeks in overweight or obese adults concluded that green tea preparations appear to cause a small, statistically non-significant weight loss that is not likely to be clinically important, with no significant effect on keeping weight off. The NIH Office of Dietary Supplements says green tea might help you lose a small amount of weight.

A drink is not an extract. The National Center for Complementary and Integrative Health reports no safety concerns for green tea as a beverage in adults. It says extracts in tablet or capsule form can cause nausea, constipation and higher blood pressure, and that liver injury has been reported, uncommonly. Extract can also lower blood levels of the cholesterol drug atorvastatin, so ask your pharmacist before trying one.

What about coffee and caffeine?

In the same meta-analysis, caffeine-only supplementation increased 24-hour energy expenditure by 4.8 percent, while the increase in fat oxidation was not statistically significant. The FDA says 400 milligrams of caffeine a day, about two to three 12-ounce cups of coffee, is not generally associated with negative effects in most adults. Talk to your provider if you are pregnant or have a condition caffeine may affect.

Do chili peppers and capsaicin boost metabolism?

A little. A 2012 systematic review in Appetite covered 20 trials and 563 participants and found that capsaicinoids, the compounds in chili peppers, increased energy expenditure by about 50 calories a day and reduced appetite. The reviewers said capsaicinoids are not a magic bullet. The NIH Office of Dietary Supplements says capsaicin has not been studied enough to know if it helps weight loss, and that it can cause stomach pain, burning and nausea.

Which foods support the thyroid, and does that speed up metabolism?

Iodine-rich foods support thyroid hormone production, but nothing here shows they increase metabolic rate above normal levels. The NIH iodine fact sheet says the body needs iodine to make thyroid hormones, which control metabolism. Most people in the United States get enough, and too much can cause goiter and thyroid inflammation. If your weight rises despite steady habits, the National Institute of Diabetes and Digestive and Kidney Diseases lists hypothyroidism among health problems that may lead to weight gain, so your clinician can help decide whether testing makes sense for your health.

Does energy expenditure drop after 40?

In one large data set, energy burn adjusted for fat-free mass stayed stable from age 20 to 60, then declined. A 2021 analysis in Science measured energy expenditure with doubly labeled water in people aged 8 days to 95 years. It measured energy expenditure, not belly fat, sleep or hormone symptoms, so it cannot explain menopause weight gain. For that, see my guide to weight loss during menopause.

What else affects energy balance?

A 2019 randomized trial in Cell Metabolism admitted 20 weight-stable adults, average age 31, to the NIH Clinical Center for two weeks on an ultra-processed diet and two weeks on an unprocessed one. People ate 508 more calories a day on the ultra-processed diet and gained 0.9 kilograms, versus losing 0.9 kilograms on the unprocessed diet. It was small and short. The main finding was higher intake, and the researchers also measured energy burn, which was slightly higher on the ultra-processed diet, so the trial does not show that processed food slows metabolism.

In a follow-up in Obesity of 14 “The Biggest Loser” contestants, resting metabolic rate was 704 calories a day below baseline six years later, after they had regained an average of 41.0 kilograms of the 58.3 they lost. After adjusting for body composition and age, the researchers calculated about 499 calories a day of metabolic slowing. There was no comparison group, and the contestants combined extreme dieting with heavy exercise, so it may not apply to a modest loss. Muscle is the other lever food cannot replace, and my guide to strength training for women over 40 covers the evidence.

This page is general health information, not medical advice, and I am not a medical professional. If you have thyroid disease, diabetes, kidney disease, an eating disorder history, take prescription medicines, are pregnant or nursing, or use a GLP-1 medicine, talk with your prescriber or a registered dietitian before changing how you eat.

Frequently Asked Questions

Is there a food that burns belly fat?

Nothing in the research above supports the idea that one food burns belly fat, and the research above points to small effects.

How many calories does a high-protein meal really burn?

Reported values put the digestion cost of protein at 20 to 30 percent of its calories, so 400 protein calories would use roughly 80 to 120. Carbohydrate costs 5 to 10 percent, so 400 carbohydrate calories would use roughly 20 to 40, a gap of about 40 to 100 calories.

Does eating spicy food every day help me lose weight?

The 2012 review in Appetite looked at capsaicinoids, the compounds in chili peppers, and estimated about 50 extra calories burned a day. It does not say how much chili in a meal would do that. The NIH Office of Dietary Supplements says capsaicin has not been studied enough to know if it helps weight loss, and capsaicin can cause stomach pain, burning and nausea.

Are metabolism-boosting supplements regulated?

The NIH Office of Dietary Supplements says these products do not need FDA review or approval before sale, and makers do not have to show the FDA that they are safe or effective. Ask a pharmacist about interactions before you try one.

Does losing a lot of weight slow metabolism long term?

The Biggest Loser follow-up found slower metabolism six years later, but in only 14 people after very large losses, so it does not show how often this happens after ordinary diets.

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