A New England Journal of Medicine study in 2007 concluded social networks have greater influence than genetics on the likelihood of being overweight. A person’s chance of becoming obese increased 57% if he or she also had a friend who became obese during a given time. The risk was even greater (71%) if the sibling or friend was the same gender. 

Taken literally, your chances of staying slim are greatest if:

• You don’t associate with overweight friends

• You have a thin spouse

• You’re friends with skinny neighbors, but acquaintances with fatter ones. 

It’s not all bad news. The study’s silver lining is that as those closest in your social network improve their health habits and shed pounds, you will too. 

What it means for health promoters

While we’ve always advocated health is a personal responsibility, there’s no denying how a strong support network and environment greatly increase an individual’s chance for success. With that in mind, health promoters should reexamine all the ways to have a positive influence on social networks. Some ideas:

• 2 for 1 programs. Consider, where you can, buddy services for weight control — from registration incentives to coaching services to rewards.

• Families fight fat. Food choices are learned at home and reinforced by family traditions. It only makes sense that your program underscore family nutrition and food preparation. Explore how to bring families to the table to learn and practice healthy eating.

• Team competitions. Properly executed team competitions create camaraderie and support for the health goal. Be sure your competition emphasizes behavior, not outcomes only, so everyone has a chance to be successful.

• Share your success opportunities. Create a standard form (on paper and online) where individuals can detail accomplishments and indicate their interest in being a mentor for someone attempting the same behavior change. Be sure to interview the potential mentor to confirm appropriateness of their approach and offer guidelines.