It’s not uncommon for friends to hang out at the same place, share similar interests, or even shop at the same stores. What may be surprising, though, is that teens with overweight friends may develop a weight problem too. In essence they can “catch” bad eating and lifestyle habits from their heavy friends.
One study looked at 5,000 teens with imitative obesity traits, meaning that teens subconsciously chose to eat and do things that caused weight gain—simply because their friends were heavy. The researchers understand that teens might be more inclined to hang out with friends of a similar size, but they also noted that teens are highly influenced by each other’s behavior.
Here’s an example. Teens often meet up and eat meals away from home—usually in fast food outlets. If they are with friends who don’t take their health or weight seriously, then they may be more apt to order unhealthy junk food. If they’re out with more health-conscious friends, then they’ll probably order healthier food.
That’s the power of the social network.
This is not the first study to look at how friends influence weight gain, though. Back in 2007, the New England Journal of Medicine published a study suggesting that obesity is “socially contagious,” spreading from person to person in a social network. Interestingly, the researchers found that the greatest weight impact was not with those sharing the same genes or household, but among friends.
Here’s what they found. After studying networks of obesity, they found that if someone's friend becomes obese, that person's chances of becoming obese increase by more than half—57% to be exact. Among mutual friends, the effect is even stronger, with chances increasing by a whopping 171%.
On average, having an obese friend influenced a person to gain 17 pounds, which put many people over the body mass index (BMI) measure for obesity. What’s more is that this socially infectious, weight-gaining effect is much greater among friends of the same sex. You have a 71% increased risk of obesity if your same-sex friend gains a lot of weight. The reason? Maybe it’s that love is blind. In short, the esteem you have for your friend may mess up your perception of what a normal or healthy body size is.
This is in no way an excuse to not hang out with your heavier friends; it is an opportunity, however, to become more aware of how friends influence one another—for good or bad. In fact, the same momentum that is used to influence poor eating and lifestyle habits might be used to catalyze proper eating and exercise.
You’ve no doubt heard the slogan, “Friends don’t let friends drive drunk.” Well, friends shouldn’t influence friends to be fat, either. Use your social networks and friendships for good, and start spreading positive health behaviors.