Real Life Nutrition

By Janet Helm, MS, RD

You might not even realize it, but your friends may hold a lot of power when it comes to your health. In fact, many researchers believe that the key to making lasting, positive changes in your life is to create a supportive social network.

That’s the topic of a new book called The Social Network Diet, by Miriam Nelson and Jennifer Ackerman, and it’s the focus of several new studies.  It turns out, our social environment – the network of people we spend time with, our family, friends, and peers – has a significant influence on our habits and our health. This social network effect was first observed in 2007 when Harvard researchers released a study that tracked  12,067 people for more than three decades and found that the risk of becoming obese spread almost like a virus from person to person.

Friends are more powerful than our genes when it comes to weight gain, the researchers concluded. A person’s chance of becoming obese climbed by 57 percent if a friend of the same sex became obese. This effect was even stronger among close friends. Among close mutual friends, if one friend became obese, the other friend’s chances increased by 171 percent.

So what’s going on? Miriam Nelson, a nutrition researcher at Tufts University, believes that when someone becomes obese, it becomes more socially acceptable for people close to that person to gain weight. The change in social norm of acceptable body size can spread quickly, rippling through social networks, even among people who live hundreds of miles away from one another. She believes that these changing norms are one reason for the rapid spread of obesity.

On the positive side, there’s growing evidence that losing weight may be similarly “contagious.”   A new study published in the journal Obesity took a look at an annual state-sponsored competition in Rhode Island that joins individuals to compete against one another to see which team loses the most weight. The participants who lost the most weight were on the same team, suggesting “significant social influence.” Lead author Tricia M. Leahey from Brown University believes teammates were influenced by each other, perhaps by “providing accountability, setting expectations of weight loss, and providing encouragement and support.”

Individuals who reported higher levels of teammate social influence increased their odds of losing weight by 20 percent. This effect was stronger than any other team characteristic, Leahey said in a press release. “This is the first study to show that in these team-based campaigns, who’s on your team really matters,” she added. “Being surrounded by others with similar health goals all working to achieve the same thing may have really helped people with their weight loss efforts.”

So surround yourself by a good team. Get the support you need from your tribe. Think about how you can lean on your social networks – whether that’s online or offline – to create a positive social environment that will encourage and support your healthy habits.

Have social networks or your circle of friends helped or harmed your healthy habits? Share your stories in the comments below.