Modest Financial Incentives Help with Weight Loss

Tying payments to weight, rather than behaviors, marginally more effective

More than one-third of U.S. adults grapple with obesity, according to the Centers for Disease Control and Prevention.

Beyond the personal cost to individuals — a higher risk for diabetes, heart disease and some cancers, as well as heightened social stigma and workplace bias — our health care system spends more than $175 billion annually to treat obesity-related illness.

Results from a field experiment published in JAMA Internal Medicine make a case that strategic spending in the form of direct payouts to individuals who have lower incomes and are obese may be an effective way to encourage weight loss.

Participants who were given weight management resources (such as a Weight Watchers membership) and a series of financial incentives for hitting certain milestones were more likely to have lost 5% of their body weight within six months than participants who received the resources, but no cash carrot.

Money as Extra Motivation

Between November 2017 and March 2020, more than 650 individuals (each lower income and obese; 80% were women) were enrolled in this study through 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 participants into one of three treatment groups.

A control group of sorts was given resources to help them focus on weight management. That included a one-year membership to WW Freestyle, the current branding of Weight Watchers. Participants were encouraged to attend a meeting at least two times a month. Participants were also given a digital scale and encouraged to weigh themselves at least three days a week, as well as 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 midstudy) per week of moderate to vigorous physical activity. 

A second group was given the same resources and a series of financial payouts for hitting certain behavioral goals, but payments were not tied directly 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 they also attended two of the meetings per month. Participants in this group could also receive payments for keeping a weight loss diary, recording their weight at least three times a week and hitting exercise milestones.

A third group received the same resources, but their financial incentives — again, a max of $750 over six months — were tied to hitting specific weight-loss milestones. Participants in this group would receive $50 if they lost at least 1.5% to 2.5% of their starting weight in the first 30 days, or $100 if they lost more than 2.5%. At the two-month and three-month weigh-ins they were eligible for another $50 if their weight loss was at least 2.5%-to-5% or $100 if their weight loss was more than 5%. In the final three months, the payout for a weight loss of 2.5% up to 5% was increased to $100 each month and $150 for each month if their weight loss was more than 5%.

The researchers were focused on how many people in each group managed to lose at least 5% of their starting weight at the six-month mark. The researchers chose the six-month focus based on prior research that established it takes that long for a change in behavior to begin to stick as a lifestyle habit. Nearly 500 of the original 688 enrollees were still participating at the six-month mark. That said, participants were followed for a full year and 364 of them stayed active for 12 months.

Results included:

• Among the participants given support and resources but no financial incentive, 22% had lost at least 5% of their weight at six months. After a full year, nearly one-third had lost at least 5%, a significant increase.

• Among participants given financial incentives for reaching behavioral goals, 39% lost at least 5% of their baseline weight after six months. A year out, 42% reached that level, a slight uptick.

• Among those paid for specific weight loss, 49% lost at least 5% of their body weight at six months. At the one-year mark, this group experienced some backsliding, with 41% showing at least a 5% loss of body weight.

The researchers note the limits of the compressed time frame of this study. The encouraging results of financial incentives — especially when tied to behavioral goals — make a case for studying whether the same incentives may be able to jump-start weight loss that persists over longer periods.