Did you know that fat comes in two distinct, if unimaginative, colors – white which offers insulation and stores extra energy, and brown adipose tissue which burns energy to produce heat?

Brown fat, which makes up as much as 5% of their body weight, helps keep babies warm, but no one knew how much adults retain, or how active it might be.

Researchers were not sure if adults had any of this “good fat; and others were convinced that it had no connection with a persons weight. The latest research changes all that.

Studies have been progressing for ages looking at brown fat in the hope of discovering ways to unlock its secrets.

Three new pieces of research in the April 9, 2009 issue of The New England Journal of Medicine (NEJM) confirm that brown fat is indeed present in adults, and it can be detected when exposing subjects to cold temperatures.

Most of us have quite small amounts of this fat around our collarbones and in the neck area, with women having two times as much on average, then men.

In some cases, those who have more active areas of brown fat were not as “weighty” leaving experts to wonder if this type of fat was effecting a persons overall weight.

“Fifty grams of maximally activated brown fat accounts for 20 percent of your resting energy expenditure”, explains Dr. Aaron Cypress of the Joslin Diabetes Center in Boston, who led one of the studies. “If you add that up, that’s 400 or 500 calories per day. So maybe a little of this good fat could go a long way.”

In a second study, Finnish researcher Dr. Kirsi Virtanen of the University of Turku and colleagues used positron emission tomography (PET) scans to identify active brown fat deposits in healthy subjects.

The brown fat became more active when the subjects were left in a chilly room for several hours. Experts found that this fat, unlike the white kind, burns calories faster in colder temperatures.

In the study, the metabolism was boosted on average 15 times, than in the area where the white fat cells reside.

So, could this brown fat play a role in metabolism also?

Another work, also in the same issue of the NEJM, carried out by a team at Maastricht University Medical Center discovered that obese men had less brown fat than subjects who were leaner.

They also found that people seem to have less brown fat as they get older, and that spending even small amounts of time in a chilly place can activate this type of fat.

These studies show that adults do have functional brown fat in our bodies. Though no one knows what role brown fat might play in weight loss in the future, researchers are hoping for big things.

Maybe further research will uncover a way to help the body produce more brown fat; or just activate the potentially good fat cells we have now. Possibly a drug could target some parts of brown fats metabolic mechanisms, maybe a procedure could remove the brown fat, amplify it somehow and return it to the body.

Cypress believes that activating the brown fat is key, though whether this would make people lose weight has yet to be tested.

Who knows if turning on this type of fat might just not make the body want to eat more?

If you’d like to try and activate your own brown adipose tissue, turn down the heat, or spend more time outdoors in a cooler climate.

Temperatures of 61 degrees were used on the participants, and they might be enough to have your own heat creating, fat burning engine running in no time.

Next – just head on over to the Daily Health Bulletin for more information on how brown adipose tissue burns calories, plus for a limited time get 5 free fantastic health reports. Click here for more details on these studies on brown adipose tissue.