We already knew that exercise could induce a transformation of white fat to brown," he said. "This simply characterizes the intermediate state. The functional significance of this 'beige fat' appears to be what we already knew: exercise, and cold, can raise energy expenditure in part through the activation of brown fat."
The hope, of course, is that the beige fat cells might one day lead to new treatments for obesity and diabetes. Dana-Farber has licensed both discoveries to Ember Therapeutics, a biotech company founded by Spiegelman. Keith Ayoob, associate clinical professor of pediatrics at the Albert Einstein College of Medicine, said that this research will be crucial in determining whether anything useful can come from this discovery.
"We need to know more about how much is there, why some people may have a greater or lesser proportion of it, and to see if it can be of use in helping people lose weight," Ayoob said. "There may be a way -- probably via a drug -- to stimulate either the production of beige or brown fat over white fat, or to increase fat breakdown.
Would such a drug be a good idea? Katz said he remains skeptical, saying that he believes the finding means "that the quest for a magical means of tickling both brown and beige fat into burning more calories ... without the ... inconvenience of actually exercising or eating better will continue in earnest.
"To date, our efforts to tickle the metabolic engine in this selective manner have reaped a whirlwind of unintended consequences, and frankly, I see that peril around this corner as well."
As for using cold and shivering as an alternative to exercise – some diet gurus are already recommending this – Spiegelman says forget about it.
"Anyone can write a book to say it works, but this demands serious research and clinical trials," he said. "We've never done the experiments before, and it would be a pretty uncomfortable therapy, so realistically I don't think it's a good road to travel down."