Weight Gain: It May Be Contagious

If you’ve been putting on weight, you might want to tell your friends and family to watch out. New research indicates that you’re more likely to become obese if you see your friends and family gain weight. For example, if you have a sibling who becomes obese, your risk for obesity goes up 40 percent. If it’s a close friend who puts on excess weight, your risk increases 57 percent. Same-sex friends and relatives have more influence on a person’s weight gain than friends of the opposite sex. And it doesn’t matter if your friend or relative lives next door or across the country. The closeness of the relationship is more influential than the physical distance between people. Researchers think that obesity can spread like this because people begin to accept obesity when they see it in their own friends and family.

The New England Journal of Medicine, Vol. 357, No. 4