So say researchers from Harvard Medical School and the University of California, who published research in a July 2007 edition of the New England Journal of Medicine. After analyzing data from 12,067 individuals, they found that when one individual becomes obese, the chance that his or her friend will become obese increases by 57 percent-even if their friend lives far away, and especially if their friend is of the same sex-71 percent in that case. Other members of people's "social network" were also affected: their siblings' risk increased by 40 percent and their spouses' by 37 percent. In contrast, a neighbor, if not a part of their social network, experienced no increase in risk.
Obviously, weight gain isn't contagious in the same way a cold is contagious. Rather than being spread through the transmission of bodily fluids, like a virus, obesity is "socially" contagious-it can be spread through the transmission of behaviors and social norms. People within a social network often engage in health-impacting behaviors together, such as Friday night parties with too much wine and cheese or working lunches of fatty restaurant fare. These behaviors may result in weight gain, especially if they become habits. Even more importantly, each person within the social network serves as a standard by which others in the network may compare themselves. The 10-pound weight gain your best friend is wearing makes you feel a little less guilty about the extra five pounds you're sporting, and if fast-food is an acceptable meal for your sister-in-law, you may develop a more lackadaisical attitude about dinner in your own house.
BabyFit Tip: Don't trade in all of your overweight friends for trimmer models just yet. Rather than asking what your friends can do for you, ask what you can do for your friends. Examined from a different angle, this study shows that while unhealthy behaviors are contagious, so are healthy ones. Instead of waiting for your friends to get on the path to a healthy lifestyle, assume the role of the trailblazer in your group. Suggest hiking instead of a trip to the movies, and you'll all benefit.
Here are some ways to spread your healthy habits to your friends and family:
- Join a gym with a buddy (or even your partner). Many times, membership rates are lower (and the workouts are more fun) when you're with a friend. And just think of how many people the two of you have the power to influence!
- Choose social activities that are active. If you're into sports, organize or join a soccer team. Evening walks with a nearby friend, indoor rock climbing, bicycling, bowling and canoeing are other good bets.
- Throw a fitness party to share the fun of exercise with your friends.
- Get connected with a MommyTeam. Be a model of good health habits to other BabyFit members, and sit back while they positively impact you. You can join an existing Team or start one of your own.