MaRS

Battling obesity

Gotcha!  Who could pass up such a compelling title?

So what’s this all about?  Well, the theme here is brown adipose tissue (“brown fat”) and its contribution to body weight.

There has been a lot of debate over the years on the role of brown fat in adults and even whether it is present at all.  Brown fat is generally accepted to play a role in helping newborns and infants maintain body temperature in a cold environment.

A group of papers published in the April 9, 2009 issue of the New England Journal of Medicine suggests that brown fat is not only present in adults but that it can make a major contribution to maintenance of body weight.

Aaron Cypess and colleagues at the Joslin Diabetes Center demonstrated that brown fact is active in adults and its amount is inversely correlated with Body Mass Index. Meanwhile, Kirsi Virtanen’s group (University of Turku, Finland) showed that brown fat burned substantial amounts of glucose when the subjects were subjected to cold.  Finally, Wouter van Marken Lichtenbelt and co-researchers in Maastricht, Netherlands confirmed that brown fat was activated by cold temperatures in adult men and that its amount was reduced in overweight or obese subjects.

Given that 50 grams of brown fat can burn 400-500 calories per day (equivalent to nine pounds of fat a year), it appears that the overall contribution of brown fat to metabolism and weight loss is significant.

Future work will focus on finding ways to expand the pool of brown fat and methods for activating existing brown fat stores.  Both measures should allow “effortless” weight loss.

Bad news for the spandex industry.