Health claims: Shorts that freeze your fat off

Part of an ongoing series looking at the reality behind health claims.

Claims: FreezeAwayFat Cool Shape shorts ($99.95)are equipped with gel inserts that, when cooled, “could help you activate brown fat cells that burn more calories, diminish appearance of white fat deposits and help contour problem areas,” according to the press material. Simply tuck the cold packs into the shorts (around the thighs, buttocks, hips and tummy) “to target white fat cells and place one in the small of the back where brown fat cells are more dense, to create a slimmer shape,” the company says.

Reality: Our bodies contain both brown and white fat cells. Brown fat cells, which are loaded with mitochondria, are considered higher quality than white fat cells and thought to help burn incoming calories. White fat cells store excess energy from food in blobby, shapeless lumps throughout the body.

Standing in a cool room (60 to 62 degrees Fahrenheit), or cooling a part of the body by wearing a cooling vest “can activate brown fat cells and energy expenditure,” said Dr. Ronald Kahn, a professor of medicine at the Joslin Diabetes Center and Harvard Medical School, whose research suggests that brown fat cells could have a role in metabolism.

“But this is different from claims of destroying subcutaneous white fat cells by cold temperature,” said Kahn, who is skeptical of the statements. “Generally speaking, if you get rid of subcutaneous fat (which is also what liposuction does) it does not improve metabolism. Any effects are strictly cosmetic.”

Research has shown healthy people tend to have more active brown fat than their less healthy, older or more overweight counterparts. But it’s not known whether the brown fat contributed to better health or whether healthier people have more brown fat. Scientists also don’t yet know whether brown fat actually plays a protective role against obesity, though some animal studies have shown that eliminating brown fat in rodents leads to excessive weight gain.

The sisters who developed the cooling shorts, Jamie Burke and Lark MacPhail, are targeting women who try to eat a healthy diet and exercise but can’t get rid of the fat in problematic areas. MacPhail said that when she wore the shorts for 30 minutes a day, her once-snug clothes felt loose after about five weeks.

That’s not exactly rigorous science. Still, even if there’s no evidence showing the polyester/lyrca shorts can help you freeze your butt off, they are certainly refreshing and could be great for athletes who want to cool down after a hard workout.

Or simply wear them on a hot July day. You can walk around, empty the dishwasher, make dinner or sit at a desk--and the icepacks stay in place.