Linking payments to weight rather than behavior is marginally more effective
According to the Centers for Disease Control and Prevention, more than a third of US adults struggle with obesity.
Aside from the personal costs to individuals—a higher risk of diabetes, heart disease, and some cancers, as well as increased social stigma and workplace prejudice—our healthcare system spends more than $175 billion annually treating obesity-related diseases.
The results of a field trial published in JAMA Internal Medicine show that strategic spending in the form of direct payments to those on lower incomes and those who are obese can be an effective way to promote weight loss.
Participants who received weight management resources (e.g., a Weight Watchers membership) and a variety of financial incentives for meeting certain milestones were more likely to lose 5% of their body weight over a six-month period than participants who received the resources received but no money carrot.
Money as additional motivation
Between November 2017 and March 2020, more than 650 people (both lower-income and obese; 80% were women) were enrolled in this study across two New York City hospitals (Bellevue and NYU Langone Health) and Olive View-UCLA Hospital. A team of 16 researchers, including UCLA’s Noah Goldstein, Soma Wali, Chi-Hong Tseng, Un Young Rebecca Chung, Miguel Cuevas and Robert Ponce, then sorted the participants into one of three treatment groups.
Joseph A. Ladapo, MD, PhD, University of Florida; Stephanie L Orstad, PhD, NYU Langone Health; Soma Wali, MD, Olive View-UCLA Medicine Center; Judith Wylie-Rosett, EdD, RD, Albert Einstein College of Medicine; Chi-Hong Tseng, PhD, UCLA; Un Young Rebecca Chung, BS, UCLA; Miguel A Cuevas, BS, UCLA; Christina Hernandez, MPH, NYU Grossman School of Medicine; Susan Parraga, BS, NYU Grossman School of Medicine; Robert Ponce, BS, Olive View-UCLA Medical Center; Victoria Sweat, MA, NYU Grossman School of Medicine; Sandra Wittleder, PhD, NYU Grossman School of Medicine; Andrew B. Wallach, MD, NYU Langone Health; Suzanne B. Shu, PhD, Cornell Dyson School of Applied Economics and Management; Noah J Goldstein, PhD, UCLA; Melanie Jay, MD, NYU Langone Health
A sort of control group received resources to help them focus on weight management. This included a one-year membership of WW Freestyle, Weight Watchers’ current branding. Participants were encouraged to attend a meeting at least twice a month. Participants were also given a digital scale and were encouraged to weigh themselves at least three days a week and use an app-based food diary to track what they ate. They also received a Fitbit tracking device and were encouraged to commit to at least 75 minutes (increased to 150 minutes during college) per week of moderate-to-vigorous physical activity.
A second group received the same resources and a series of financial payments for meeting specific behavioral goals, but the payments were not directly related to weight loss. The maximum that could be earned was $750 over six months, including $150 for attending at least two of the WW Freestyle meetings in the first month and then $60 for each month that they also attended attended two of the meetings per month. Participants in this group could also receive payment for keeping a weight loss diary, tracking their weight at least three times a week, and achieving exercise milestones.
A third group received the same resources, but their financial incentives — again, a maximum of $750 over six months — were tied to meeting specific weight-loss milestones. Participants in this group would receive $50 if they lost at least 1.5% to 2.5% of their baseline weight in the first 30 days, or $100 if they lost more than 2.5%. At the two and three month weigh-in, they were eligible for an additional $50 if their weight loss was at least 2.5% to 5%, or $100 if their weight loss was more than 5%. In the past three months, the payout for weight loss has increased from 2.5% up to 5% to $100 per month and $150 for each month if the weight loss is more than 5%.
Researchers focused on how many people in each group managed to lose at least 5% of their baseline weight after six months. The researchers chose the six-month focus based on previous research, which found that it takes that long for behavior change to become a habit. Almost 500 of the original 688 enrolled were still taking part after six months. However, the participants were followed for a full year and 364 of them remained active for 12 months.
- Of the participants who received support and resources but no financial incentive, 22% had lost at least 5% of their weight after six months. After a full year, nearly a third had lost at least 5%, a significant increase.
- Among participants given financial incentives to meet behavioral goals, 39% lost at least 5% of their baseline weight after six months. A year later, 42% reached that level, a slight increase.
- Among those paid for specific weight loss, 49% lost at least 5% of their body weight after six months. After one year, this group experienced some relapse, with 41% showing a loss of at least 5% of body weight.
The researchers note the limitations of the compressed time frame of this study. The encouraging results of financial incentives, particularly when tied to behavioral goals, suggest investigating whether the same incentives might be able to spur weight loss that lasts over longer periods of time.