You might’ve heard news reports that obesity might be contagious. What’s all this about?
A study published in the New England Journal of Medicine a few years ago followed over 12,000 people for 32 years to help determine whether being socially linked to someone was a more important determinant of developing obesity than being genetically or geographically linked: http://www.nejm.org/doi/full/10.1056/NEJMsa066082. The study found that if your friend becomes obese, you have a 57% higher chance of becoming obese yourself (and if you are close/mutual friends, your risk increases to a whopping 171% higher than strangers!). They also found that next door neighbors’ obesity did NOT increase your risk of gaining excessive fat yourself, and that good friends who are very far away geographically still DO increase your risk of gaining weight. This helps rule out exposure to something in the environment (like a virus or a poison) as an explanation, and suggests that it is a change in your thought processes — in your perception of social norms and the acceptability of obesity — that is to blame.
What does this all mean? If you are more likely to gain weight when you have friends who gain weight, then it is reasonable to assume that surrounding yourself with healthy-weight friends may keep you from gaining eight yourself. This can have enormous implications on the obesity epidemic in America. Public health programs might focus more on weight loss programs that include peer support, since both bad and good behaviors might spread over social ties/friendships.
The bottom line: if you want to maximize your chances of losing weight and keeping it off, surround yourself with like-minded people. Join a weight-loss community, such as Overeaters Anonymous or Weight Watchers, or start your own fat burners’ club at work. Spending too much time with friends who are overweight and who continue to eat unhealthily and remain sedentary might influence you without you realizing it. Try to spend a little more time with people who make healthy eating choices and get out there and exercise with you!