Wednesday, Mar. 17, 2010

Why We Get Fat: Seeking Clues in Our Cells

Losing weight can seem like an unwinnable war. You know you need to eat less and exercise more, but that's nearly impossible when everything in your life — from job stress to family crises to the temptation of fast and fatty foods — encourages you to do the opposite. A healthy diet and regular exercise are certainly the best weapons against weight gain, but the fact is that sometimes they aren't enough. And that's where science may someday be able to help.

In research labs around the country, researchers are looking closely at the biological mechanisms of obesity, figuring out — from the inside out — why some bodies store fat so readily, and why others are better at burning the calories they consume. They are discovering a surprising array of metabolic and physiologic factors that contribute to weight: did you know, for instance, that your intestines are teeming with bacteria that can promote or curb weight gain? Or that a type of hyperactive fat called brown fat — which is abundant in newborns — actually burns a lot of calories, unlike the traditional white fat that adults commonly store in their midsections?

These and other findings about the biology of weight gain could be the key to slimming our collective waistline, if scientists can someday use them to create better treatments for obesity. And we could use the help: in the decade between 1991 and 2000, the prevalence of overweight adults in the U.S. increased by 61%, according to the Centers for Disease Control and Prevention. Last year, 30% of children in 30 states tipped the scales as either overweight or obese. "With hundreds of millions of obese people that we've got in our country now, physicians can't treat them all," says Dr. Michael Jensen, professor of medicine at the Mayo Clinic in Rochester. "We just don't have enough physicians."

If the latest findings from obesity labs — in both humans and animals — prove as practical as they are promising, they could someday make the job of fighting obesity easier for physicians and patients, and help all of us get an extra boost from our diet and exercise programs.