Teaming Up Helps People Lose Weight

Study of an RWJF Community Health Leader's program shows how social influences and team support help individuals take off pounds.

    • May 10, 2012

“We live in an obesogenic environment,” says Rajiv Kumar, MD. “In our workplaces, people bring doughnuts every Monday and bagels every Tuesday. We take the elevator to the second floor without thinking about the stairs. We compete to get the parking spot closest to the door.”

As a first-year medical student at Rhode Island’s Brown University, Kumar sought to turn the tables: What if people competed, instead, to see who could lose more pounds and work out for more hours? What if they influenced each other to eat less rather than more, carrots instead of doughnuts? In 2005, Kumar founded Shape Up Rhode Island to involve Rhode Islanders in a team-based, internet-tracked fitness and weight loss competition. For his efforts, he was named a Robert Wood Johnson Foundation (RWJF) Community Health Leader in 2009.

Now, after studying successive years of Shape Up Rhode Island data, Kumar and colleagues have concluded that individuals’ weight loss outcomes were significantly influenced by team factors, such as having multiple teammates pursuing weight loss and having supportive social interactions among those teammates. The study Kumar co-authored, “Teammates and Social Influence Affect Weight Loss Outcomes in a Team-Based Weight Loss Competition,” was published in the March 2012 issue of the journal Obesity.

Kumar’s focus on obesity prevention was inspired by the patients he met as a medical student working in clinics. “Almost every patient had a goal to improve their health—to lose weight, eat better, lower their cholesterol or blood pressure—but almost everybody was failing to reach those goals,” he recalls. “A few patients did succeed, and when I talked to them and tried to understand what helped them succeed when everyone else was failing, these people always said the same thing: that they didn’t do it alone. When they joined the gym, they joined with an exercise buddy. When they decided to lose weight, they did it as a group, at a Weight Watchers club or with colleagues at work, or as a family by changing how they shopped for groceries and cooked. They made these attempts with people who motivated them and held them accountable.”

The patients’ reports “got me thinking about group-based behavior change,” Kumar says now. “But to get people activated and up off the couch, I knew we would have to do more than provide a group—we would have to make it fun. So we created a group-based behavior change model in the form of a game. It was a competition where people would form teams by asking family and friends to sign up with them and then compete to see who would lose weight and increase their exercise.” The first 12-week session of Shape Up Rhode Island in March 2006, advertised chiefly by word of mouth, drew nearly 2,000 participants. Competing team members tracked progress on a website within three divisions: hours exercised, steps logged on a pedometer, and pounds shed. Achievements were rewarded with certificates and fitness-themed prizes. Soon, Rhode Island businesses were calling Kumar to ask if they could sponsor the program for their employees.

By 2009, when Kumar received the RWJF Community Health Leaders Award for his work with Shape Up Rhode Island, 35,000 people had taken part in the program. “Given their ability to reach large numbers of people, low-intensity, statewide, team-based weight loss initiatives have the potential to make a significant public health impact,” the Obesity study contends. But maximizing that impact would require a deeper understanding of the group dynamic that had intrigued Kumar from the start—specifically, how teams’ characteristics and members’ influences on each other affected outcomes.

A study of Shape Up Rhode Island data on exercise, published in 2010, “suggested that exercise was contagious—when individuals joined a team that was more active than they were, they were pulled up, and if they joined a team that was less active, they were pulled down,” Kumar says. “So there were network effects on physical activity, and we wanted to see if that was true for weight loss.”

The weight loss study looked most closely at 3,330 of the some 12,000 participants in Shape Up Rhode Island 2009: those who were clinically overweight or obese (a body mass index of greater than 25) when they started, who enrolled in the weight loss division, and who completed the 12-week program. About 34 percent of the completers reported at least a 5 percent weight loss, about 6 percent of completers reported a 10 percent weight loss–and the people losing these significant amounts of weight generally were clustered on the same teams. “These results suggest than an individual’s weight loss was influenced by his/her team members’ weight loss,” the study concludes.

The study also looked at how outcomes were affected by “social influence,” an amalgam of factors that ranged from having close friends on the team and working out together to receiving pep-talk emails. This social influence effect “was stronger than any other team characteristic” in encouraging weight loss, the study found. The participants who said their teammates had strongly influenced their weight loss were also those who had achieved the most significant weight reductions.

In the United States, “we’re surrounded by influences that encourage unhealthy and sedentary behavior—and if we leave that unchecked, we’ll all gain weight together,” says Kumar. “So if we want to lose weight as a society, we have to intentionally design interventions that take advantage of the social connections that exist between us. This study doesn’t prove that weight loss is contagious, but it’s highly suggestive that it is.”

A few years ago, Kumar and several colleagues took a break from medical school, raised $9 million in venture capital, and started ShapeUp, Inc., a national, for-profit company built on the Shape Up Rhode Island model. Kumar says its programs “are now in use at 150 companies, covering a total of about two million people in 93 different countries and 16 languages. We use social gaming and technology to activate companies’ employees to take control of their health, increase their exercise, and lose weight.”

In April 2012, Kumar took the accumulated expertise from his academic, non-profit, and for-profit ventures to TEDMED, an annual health and medicine conference affiliated with the global TED (Technology, Entertainment, and Design) conference series. TEDMED hosts the Great Challenges Program, an RWJF-sponsored effort to draw attention to critical health and wellness concerns. At the April conference in Washington, D.C., advocates sought to convince TEDMED delegates to vote for their cause as one of 2012’s top 20 challenges. Kumar lobbied “on behalf of challenge #22, inventing wellness programs that work—and we ended up coming in first place,” he says. “So now I will serve as spokesperson for this challenge at TEDMED for the next year. We’ll use what we’ve learned at ShapeUp to inform the national conversation about how we can work together to make wellness programs better, cheaper, and more scalable.”

“Teammates and Social Influence Affect Weight Loss Outcomes in a Team-Based Weight Loss Competition” was published in the March 2012 issue of the journal Obesity. Co-authors are Kumar and Brad M. Weinberg, MD, of ShapeUp, Inc.; and Tricia M. Leahey, PhD, and Rena R. Wing, PhD, of the Department of Psychiatry and Human Behavior at the Alpert Medical School of Brown University.