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Member Research & Reports

Member Research & Reports

Northwestern Finds Social Network Connections Associated with Better Weight-loss Outcomes

If you want to lose pounds using an online weight management program, don’t be a wallflower. A new Northwestern Medicine study shows that online dieters with high social embeddedness – those who logged in regularly, recorded their weigh-ins and ‘friended’ other members – lost more than 8 percent of their body weight in six months.

The less users interacted in the community, the less weight they lost, the study found. “Our findings suggest that people can do very well at losing weight with minimal professional help when they become centrally connected to others on the same weight loss journey,” said Dr. Bonnie Spring, an author of the study and professor in Preventive Medicine. The study, published Jan. 28 in the Journal of the Royal Society Interface, is the first to use data from an online weight management program to investigate social network variables and reveal which aspects of online social connectedness most strongly promote weight loss.

The scientists found that users who did not connect with others lost about 5 percent of their body weight over six months, those with a few friends (two to nine) lost almost 7 percent and those with more than ten friends lost more than 8 percent. “There is an almost Facebook-like social network system in this program where people can friend each other and build cliques,” said Dr. Luis Amaral, professor in Medicine and the McCormick School of Engineering and senior author of the study. “In this case, we found the larger your clique, the better your outcomes.”

Dr. Spring had access to a large dataset from’s online weight-loss community. Users of CalorieKing’s program pay a membership fee for access to weight-loss tools and an online community. Dr. Amaral’s lab had the expertise to analyze user data and uncover trends in this complex network. The data provided did not include the identities of users, but it provided their sign-up date, age, height, gender and initial weight and time-stamped activities within the online community for nearly a year. Engagement, such as recorded weigh-ins, friendship requests and online communication, was analyzed. The scientists didn’t have access to any of the text that was exchanged between users.

“We found that the frequency with which you report your weight is a good indicator of positive outcomes,” Dr. Amaral said. “If you monitor your weight, you are engaged. If you communicate online with other people you are even more engaged, and when you need support you might be able to get it. There are some nice characteristics about this social network.”

This study found that self-monitoring was associated with greater weight loss, too, but Dr. Spring was surprised that even greater weight loss was associated with being highly embedded in a network of other people trying to lose weight. “In the clinic, we don’t have the ability to connect people with such a large network of others on the same journey to lose weight,” Dr. Spring said. “I was very surprised by how lawfully each step-up in social connectedness translated into greater weight loss. We could clearly see the benefit of the online social network for weight-loss success.”

For those lacking time or geographic proximity to attend in-person weight loss treatment, an online weight loss program seems to be a good alternative, Dr. Spring said, particularly if you take advantage of the self-monitoring and social networking features.

Dr. Amaral said this online social support community approach could work in other areas of behavioral medicine — such as depression and alcoholism — where in-person meetings are recommended. “Modern life is so complex and stressful, to go somewhere for a meeting is often not practical,” Dr. Amaral said. “It is hopeful that this alternative approach, of going online for support, could work.”

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