Calorie-Burning Fat

jupiterimages

If you haven't lost all your "baby fat," be happy. New research shows it may be a good thing when it comes to burning calories. Although scientist believed that this fat went away as we got older, three recent studies show that baby fat, known as brown fat, stays with us through adulthood and can help us burn energy.

Unlike white fat, which stores energy, brown fat has the ability to burn huge numbers of calories. "Brown fat is filled with mitochondria, which are the part of the cell that burns energy," says study author C. Ronald Kahn, M.D., head of the section on obesity and hormone action at the Joslin Diabetes Center in Boston.

The fat's calorie-burning effect is activated by cold. As infants, our bodies use the brown fat to stay warm because we don't have shivering mechanisms, and even though adults don't need this heat-generating process, the affect is still activated in cooler temperatures. In fact, temperatures as mild as 61 degrees can stimulate brown fat. And it only takes a little bit of this fat to burn a whole lot of calories. "It's been estimated that as little as 50 grams can burn up to 20 percent of the calories taken in by a lean person if it's maximally stimulated," says Kahn.

Nearly everyone has some brown fat, but researchers found that thinner people had more brown fat than heavier people, as did people with lower glucose levels.

"Right now we don't know if there is anything people can do to stimulate the fat other that staying in cooler environment," explains Kahn. While there are some drugs that can active the fat, including ephedra, they have too many side effects to be considered safe for weight loss.

"We need to find drugs that can stimulate brown fat safely," adds Kahn. However, even if a diet drug that stimulates brown fat's calorie-burning power were to be developed, experts caution that it wouldn't be a cure all for obesity.

"It's easy to hear stuff like this and think 'that's the answer,'" says Bob Greene, exercise physiologist, author of The Best Life Diet, and personal trainer to Oprah Winfrey.

"It is interesting research, but don't pin your hopes on the fact that that is the secret," cautions Greene. "It's just one piece of the big picture."

Greene recommends being open to getting out in the cold, because you can get a better calorie burn, but know that it won't replace the hard work of exercise, cutting out your favorite foods and dealing with the emotional reasons behind your food choices.

Looking for more ways to burn a few extra calories? Click through our gallery of negative-calorie foods.