Your body is home to two completely different types of fat — white fat, which just sits there making your clothes feel snug, and brown fat, which burns calories and fat nonstop to produce heat. That means just making your brown fat cells work faster can make you shed pounds and lose belly fat 20 percent faster, too, on any eating plan. The best part? It’s not even difficult to do.
What is brown fat?
Not much is yet known about brown fat, also known as brown adipose tissue, one of two types of fat that humans and other mammals have. Its main function is to turn food into body heat. While scientists are just starting to understand what brown fat does, they have high hopes for studying it: If experts can figure out how white fat converts to brown fat, it could lead to a treatment for obesity.
Most, and perhaps all, adults, have small pockets of brown fat in their bodies, usually located in the sides of the neck, the shoulder and upper arms, and the collarbone area. While white fat makes up the vast majority of the fat in our bodies and is used to store any excess calories we consume, brown fat can actually burns calories to produce heat (under the right conditions). When fully activated, brown fat can generate 300 times more heat than any other tissue in the body. Just two ounces of brown fat appear capable of burning several hundred calories per day — the equivalent of a 30-minute bout of exercise.
How to Activate Brown Fat
What foods have brown fat? Well, while there are no approved drugs to increase or enhance a body's brown fat, a number of foods have been shown to help activate it. The foods that activate brown fat below have the added bonus of being healthy and nutrient-rich. Beyond eating certain foods, there are also a number of ways you can activate your body's brown fat to lose weight faster.
1. Prevent slow-downs with apples and pears.
The skins of these fruits are chock-full of ursolic acid, a compound that helps revitalize weary, aging brown fat so that it behaves as if it were energetic and young, University of Iowa research suggests. Enjoy one apple or pear daily, and you could melt two pounds of body fat every month — without dieting.
2. Shed weight faster with turkey breast.
Turkey breast is a top source of L-arginine, an amino acid that activates brown fat. British research shows eating 4 oz. daily could help you effortlessly shed five pounds in two months! Peanuts are also rich in L-arginine.
3. Double calorie burn with hot peppers.
Shivering in a house heated to a nippy 58 degrees prods brown fat to convert twice as many calories than usual into heat! Too chilly? Instead, consume 1/2 tsp. cayenne powder or a few jalapeño slices daily. Capsaicin — the active ingredient in peppers — energizes brown fat the same way shivering does.
4. Sip green tea.
Drink three 12-ounce mugs of green tea daily, and your brown fat will burn 5 percent more calories every day, a Swiss study shows. Green tea’s antioxidants help brown fat soak up one of its favorite sources of fuel — glucose. Tip: Buy green tea in bags, not as loose leaves. The tea packed into bags is finely ground, which makes it easier for the antioxidants to dissolve in water and be absorbed by your body, researchers explain.
5. Eat an unpeeled apple a day.
Apple skins are loaded with ursolic acid, a natural compound that helps build and strengthen muscle tissue — and, according to new research — also kick-start the formation of brand-new brown fat.
6. Slim down as you slumber with melatonin.
Taking one milligram of melatonin 30 minutes before lights-out can prompt your brown fat to torch up to 36 percent more calories overnight, reports the Journal of Pineal Research. Melatonin ensures your brown fat stays active even when you’re in dreamland, explains study coauthor Daniel Campos, PhD.
7. Add brown fat cells by moving around more.
Fitting in 30 minutes of physical activity daily increases your calorie-burn as much as 20 percent in 10 days, doubling your ability to slim down without a struggle, suggests research in the journal Disease Models and Mechanisms. “When you exercise, your muscles release an enzyme that actually turns bits of white fat into slimming, calorie-hungry brown fat,” says study co-author Jorge C. Quan, MD.
8. Take relaxation breaks.
Simply carving out a little time each day from your hectic schedule to unwind could boost your brown fat’s calorie burn in as little as two weeks, according to a recent Texas Medical Center study. How so? By tamping down your body’s production of cortisol, a stress hormone that makes brown fat sluggish, according to researchers. Tip: A gentle 10-minute do-it-yourself foot rub at bedtime can cut your cortisol levels 25 percent or more.
9. Chill out — literally.
Feeling “chilly” for 20 minutes daily can fire up your brown fat’s calorie-burn in as little as 24 hours, say British researchers. What’s more, the more often you’re exposed to bursts of cold, the more efficient your brown fat becomes at incinerating food to produce heat. To do: Take cooler showers and baths, wear lighter layers outdoors and keep the temperature in your home and car on the low side.
Once the brown fat that you were born with is working at its peak capacity, your body responds by converting bits of flabby white fat into this slimming calorie-burner, a Swedish study shows. And the results can be impressive: “Creating just two ounces of active brown fat could increase your calorie burn 20 percent,” says lead researcher Christian Wolfrum, PhD.
A version of this story originally appeared in our print magazine.