Is Brown Fat the Secret to Being Lean?

Oh brown fat - we hardly know you. We're all too familiar with white fat - the unwanted party guest that keeps showing up uninvited on our hips, thighs, stomach, arms, and butt. But brown fat is different. Though they share the same last name, brown fat is white fat's much cooler cousin. Instead of storing excess calories from food as "love handles" or the dreaded "muffin top," brown fat helps to burn incoming calories. How is this possible? Brown fat has a much different job than white fat.

The purpose of brown fat is to help regulate body temperature. Brown fat are specialized cells packed with mitochondria - the powerhouse of the cells. Instead of producing a high energy compound called ATP (adenosine triphosphate) to help keep us moving and shaking, brown fat cells instead burn through fuel (calories) to produce heat to help keep us warm. Brown fat is prevalent in infants and hibernating animals, which both need it to help stay warm in cold temperatures. It was previously thought that brown fat stores shrink as we age since we become more efficient at regulating our body temperature. However, recent studies indicate that adults actually retain a significant portion of brown fat in the neck area. (Sorry - there goes your excuse to act as immature as a baby or take the winter off to hibernate like a bear in your hopes of boosting your brown fat stores.)

Is there a way to harness of the power of brown fat to become a weight loss dynamo? Researchers at the Univeristy of Gothenburg in Sweden learned in experiments that exposing people to cold temperatures increased the activity of brown fat. Scientists estimate that 50 grams of brown fat could burn 20% of an average person's daily caloric intake - or about 400 calories of a 2000 calorie diet.

Now before you head off to your doctor asking for a pill or injection of brown fat or stand out in the cold shivering, it's important to keep in mind that the body is extremely efficient. A boost in calorie burning is often accompanied by a boost in appetite.

While researchers predict that real world interventions with brown fat are at least 5-10 years away, scientists also state that these treatments would only be effective when paired with changes in nutrition and exercise. (Oh snap - we still have to make lifestyle changes.) Brown fat - I guess we're still trying to get to know you.

Here are links to a few articles discussing the metabolic power of brown fat:

http://www.cnn.com/2009/HEALTH/04/10/brown.fat.obesity/index.html

http://www.time.com/time/health/article/0,8599,1890175,00.html

http://www.latimes.com/features/health/la-he-brown-fat2-2009nov02,0,3235554.story