Op-Ed: Friends with weight-loss benefits

Children born in South Los Angeles, where per capita income is $13,000, live on average 10 years less than children born in the affluent neighborhood of Pacific Palisades, according to the Health Atlas for the City of Los Angeles. This is health inequality.

There are countless reasons for this gap. Many involve food. Low-income families often live in “food deserts,” where little fresh produce is available. Fast-food restaurants abound, offering cheap, tasty but unhealthful choices. But there’s another reason for this health gap that is rarely talked about — the power of social networks.

For the Record
Jan. 29, 9:15 p.m.:
The first paragraph of this article was corrected to say “South Los Angeles” instead of “Los Angeles.”

In 1948, researchers started tracking the cardiovascular health of 5,200 residents of Framingham, Mass., and from this influential study emerged a lot of what we now know about the effects of diet and exercise on heart disease. But in 2009, two social scientists began parsing data and made a fascinating observation: When Framingham participants became obese, their friends were more than half again as likely to become obese too.

This is intuitive — if your friends smoke, you are likely to smoke. Less intuitive was the discovery that your friend’s friends can affect your health. Those who were one person removed from someone obese were 20% more likely to become obese — even if the connecting friend didn’t gain weight. So if your friend’s friends are smokers, you are more likely to smoke. In short, social norms are contagious.


This has huge repercussions for obesity. Not only does America’s toxic food environment need to be fixed, but also our social norms need to change. In affluent areas, this is already starting to happen, as people become accustomed to drinking green juice, eating tofu and doing yoga.

But in food deserts, where unhealthful eating practices persist because of necessity, it’s a different story. Even when marginal improvements in food access are made — by placing produce in corner stores, for instance, or giving children fresh fruit at school — they don’t stick because there is little social support for that kind of eating. In some schools in South Los Angeles, the majority of fruit given daily to children gets thrown in the trash, teachers say. Kids prefer the breakfast they’ve become accustomed to — which might be Cheetos and Pepsi.

To stem the spread of obesity and close the health gap, we need to use social networks to spread new norms. There’s historical precedent for this: In 1964, 42% of Americans smoked; 18% do so today, according to the Centers for Disease Control and Prevention. Raising cigarette taxes and increasingly strident cigarette-pack warnings surely helped but so did raising awareness about the dangers of secondhand smoke. Smoking gradually went from cool to disrespectful.

But smoking rates dropped mainly in affluent areas. High-income families decreased their smoking by 62% from 1965 to 1999 compared with only 9% for low-income families, according to the Campaign for Tobacco-Free Kids.

So how do you change social norms around unhealthful eating in a way that doesn’t leave low-income families behind?

At Groceryships, the L.A.-based nonprofit I run, we are developing a network of peer-led support and education groups in low-income areas. Small groups of families meet weekly to work on getting healthy together. There is nutrition education, healthful cooking classes and money to experiment with produce. Children have to try a vegetable 10 to 12 times to develop a liking, according to UCLA research, and that cost doesn’t fit into a food stamp budget.

But the backbone of each two-hour meeting is the support group aspect, in which participants discuss the challenges of adopting a healthful lifestyle while surrounded by unhealthful choices. A box of Kleenex sits in the center of the circle, testimony to how hard it is to talk about food and health without tears.

This support group format leads to deep emotional bonds — and physical changes. All of the families that have participated in our program report significantly increased fruit and vegetable consumption. The first group of seven moms to complete the six-month program all reported weight loss in their children and other family members.

Changing habits a few families at a time may seem like small ball. It’s not. The social scientists who analyzed the Framingham data theorized that the best way to fight obesity wasn’t with the support of a cluster of close friends, but to skip a link and work on getting healthy with friends of friends. When the researchers ran this scenario through their model, it worked. People all along the chain of acquaintance started slimming down.

It works because of the ripple effect. One participant at Groceryships took over breakfast duty at her church, replacing pancakes and bacon with brown rice cereal and fruit. Another started teaching a nutrition class at her child’s elementary school. The teenage skateboarding sons of another participant started hosting fruit and vegetable smoothie parties for skateboarders in the neighborhood. Participants recruit friends and neighbors, spreading healthful norms through their social networks.

In 2015, we plan to launch 10 new groups in South Los Angeles, but we are also setting it up so that anyone who wants to can recruit 10 friends and start and run an independent group, with our support.

Imagine if there were millions of these groups, making healthful norms go viral.

Sam Polk is the founder of the nonprofit Groceryships. His memoir is scheduled to be released by Scribner early next year.

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