While it'd be nice to find the secrets to a lightning-fast metabolism in a supplement bottle, that's probably just wishful thinking. It's true that some supplements might have a modest effect on calorie-burning -- at least, in preliminary studies -- but very little evidence supports the theory that a magic pill will help you lose a significant amount of weight by increasing your metabolism. Certain foods can boost your metabolism, though, so making changes to your lifestyle is the best way to manage your weight.
Caffeine and Your Metabolism
Caffeine enjoys a reputation as a metabolism-booster. It seems to make sense -- those caffeine jitters you get from a strong cup of coffee may seem as if they stem from a higher metabolism. And some preliminary research indicates that caffeine might modestly boost your metabolism after a workout, according to a study published in The Journal of Sports Medicine and Physical Fitness in 2011. The study authors looked at the effect of caffeine on exercise post-oxygen consumption, or EPOC -- the natural metabolism boost you experience after vigorous exercise -- in strength training in men. They found that caffeine increased EPOC by 15 percent, compared to the EPOC for men who took a placebo. However, this percentage still translated to just a small calorie burn, and the men who took caffeine only torched an average of 27 extra calories.
And a small human study, published in the European Journal of Clinical Nutrition in 2009, found that caffeine did increase thermogenesis -- the scientific term for calorie burning -- by 6 percent in healthy men. However, the researchers only included 12 men in the study and looked at calorie burn for just 4 hours after taking the supplement. So it's not clear whether caffeine would show the same benefits in larger studies, or if that metabolism boost is actually enough to trigger significant weight loss.
Green Tea and Fat-Burning
While green tea is another top supplement thought to increase your metabolism, the research doesn't quite match the hype. Some evidence says it helps with thermogenesis, thanks to a compound called epigallocatechin gallate, or EGCG, according to a literature review published in the Journal of Medicinal Food in 2006.
However, that slight metabolic boost might not be significant enough to help your weight loss. One study, published in Nutricion Hospitalaria in 2014, analyzed the results from over 150 prior studies on green tea -- or green tea extract -- and weight loss to learn more about how much it really helps. The researchers found that only five of the studies they reviewed were designed well enough to actually measure whether green tea helps with weight loss, and those five studies showed that it didn't offer any significant weight loss benefits.
Cayenne -- The Key to a Fiery Metabolism?
Adding some spice to your life -- usually in the form of cayenne -- has long been linked to a faster metabolism. And some evidence exists that it might help. Capsaicin, the active chemical in cayenne, seems to affect how you metabolize fat and sends chemical signals that trigger the formation of brown fat -- a calorie-burning type of fat that's associated with better weight control -- according to a literature review published in Progress in Drug Research. And human studies into the benefits of capsaicin have shown that it reduces appetite, helps with weight loss and increases metabolism through its effects on brown fat.
However, most of those benefits were experienced using a high dose of capsacin in a clinical setting, under medical supervision, and simply taking a cayenne supplement at home might not be as effective. And if you regularly eat spicy food, you might become desensitized to the potential appetite-suppressing benefits of capsaicin anyway, according to a study published in Physiology & Behavior in 2011.
Boost Your Metabolism with Food and Exercise, Not Supplements
You won't find an easy solution to weight loss; the best option is still to pair a healthy, calorie-controlled diet with regular exercise. Getting more activity can up your calorie burn throughout the day, and a strenuous workout can burn between 300 and 600 or more calories, depending on your body size, exercise intensity and length, and the activity you choose.
Eat fewer calories than you burn daily to shed weight, and opt for healthy foods with slight metabolism-boosting benefits. Protein burns calories during digestion -- about 4 times the calories you'd burn digesting carbohydrates and 10 times the calories you'd torch metabolizing fat -- so it offers a slight weight loss advantage. When you're losing weight, aim for a protein intake of 0.82 grams per pound of body weight. That amount works out to 98 grams of protein if you weigh 120 pounds, 123 grams if you weigh 150 pounds, and 148 grams if you weigh 180 pounds.
Give your metabolism a slight boost by adding ginger to your meals. While ginger on its own won't boost your metabolism, it can increase the number of calories you'll burn digesting your food, according to a study published in Metabolism in 2012. Add fresh-grated ginger to salad dressings, marinades or stir-fries, or starting your meal with DIY ginger tea, made by steeping sliced ginger in hot water.