Dieting Alone Won’t Extend Your Life, Study Suggests

Cutting calories out of your diet may help you extend your life, but only if you increase the amount of time you spend exercising, as well, recent research indicates.

Restricting fruit flies’ intake of yeast significantly increases their longevity, in part because the flies also increase their physical activity when their diet is restricted, a new study led by researchers from the Buck Institute for Research on Aging in California found. Flies that couldn’t move while on their restricted diet saw no increase in their lifespans.

Combining exercise with calorie restriction changed the way flies’ muscle and metabolism reacted, improving how they broke down fat and used it for energy. Without physical activity, however, these improvements in fat synthesis were blocked, the study authors say.

For humans, this may mean that “for dietary restriction to enhance lifespan, you need increased fat turnover in the muscle and an associated increase in physical activity,” says lead author Pankaj Kapahi, Ph.D. Cutting calories also could increase your motivation to exercise and help you get the most out of your workout, he says.

The study appears online in the journal Cell Metabolism.

(Photo © Mike Baird via Flickr)