Unlike its white counterpart, brown fat is thought to be metabolically active in that it helps burn calories and may ward against weight gain and diabetes. New research shows that exercise can increase the body’s “good” fat.
Presented at the American Diabetes Association’s meeting in Chicago in June, the research involved both men and mice, each assigned to a specific protocol. The 10 men trained on an exercise bike for 12 weeks, and the mice underwent 11 days of “voluntary wheel training.”
As a result of the training, all subjects—both mice and men—experienced a “browning” of the subcutaneous white fat. Scientists wanted to know if the brown fat would have any physiological effects. To find out, they transplanted brown fat from active mice into sedentary mice. They found that 9 days after the transplant the sedentary mice had better glucose tolerance and insulin sensitivity. The improvements persisted for at least 12 weeks posttransplant.
“Exercise training causes adaptations to subcutaneous white adipose tissue that elicit metabolic improvements in other tissues, demonstrating a previously unrecognized role for adipose tissue . . . on systemic glucose homeostasis,” concluded the study authors.