Financial incentives more effective for weight reduction than resources alone

Financial incentive strategies were more effective in reducing weight than resources such as fitness trackers and commercial weight-loss programs, a recent study found.

The prevalence of obesity in U.S. adults has increased from 30.5% in 1999 to 42.4% in 2018, Joseph A. Ladapo, MD, PhD, a professor at the University of Florida College of Medicine, and colleagues wrote in JAMA Internal Medicine.

“Because individuals with obesity are more likely than individuals with normal weight to face social stigma, including employment discrimination and bias in educational settings, the increased prevalence of obesity among lower-income individuals exacerbates health and socioeconomic disparities,” they wrote.

Evidence-based weight reduction strategies like programs, fitness devices and self-monitoring are often underused, according to Ladapo and colleagues.

“Behavioral economics, which combines concepts from economics and psychology, and financial incentives may be effective tools to address underuse, particularly when used in combination,” they wrote. “However, it is unknown whether using these tools to target behavioral goals (goal-directed design) is more or less effective than strictly targeting weight loss (outcome-based design).”

To analyze the impact of financial incentives on weight-loss management, the researchers conducted the Financial Incentives for Weight Reduction (FIReWoRk) study, a three-armed randomized trial at three different hospital-based clinics in Los Angeles and New York City.

The study consisted of 668 participants with a mean age of 47 years. Of the cohort, 81% (n = 541) were women, while 72.6% (n = 485) were Hispanic. The mean weight at enrollment was 98.96 kg, and the mean BMI was 37.95 kg/m².

All participants received a list of local weight-management programs, a voucher for 1 year of the Weight Watchers’ Freestyle program, health education and monthly one-on-one check-in visits. They were also given self-monitoring instructions and tools, including a Fitbit fitness tracker, a food journal and a digital scale.

Participants were randomly assigned into one of three groups:

• a resources-only group (n = 221);
• a goal-directed group (n = 222), which included resources and financial incentives for participating in weight-loss behaviors; and
• an outcome-based group (n = 225), which included resources and financial incentives for losing a certain percentage of weight.

Participants in both financial incentives group could earn up to $750 over 6 months. In the goal-directed group, this included a one-time incentive of $150 for registering and attending at least half of the weekly weight management programs for 1 month. They continued to receive $60 each month for attending at least half of the weekly weight management programs, while also earning up to $30 a month for using food journals at least 5 days a week and recording their body weight at least 3 days a week. Additionally, $20 could be earned by achieving 75 minutes of physical activity per week during the first 3 months of the trial. From 4 to 6 months, the physical activity requirement increased to 150 minutes.

At 6 months, the researchers reported that the adjusted proportion of participants who lost at least 5% of their baseline weight was:

• 22.1% in the resources-only group;
• 39% in the goal-directed group; and
• 49.1% in the outcome-based incentive group.

At 12 months, the proportion of participants who lost at least 5% of their baseline weight was:

• 31.3% in the resources-only group;
• 41.9% in the goal-directed incentive group; and
• 41.4% in the outcome-based incentive group.

Participants in the goal-directed group had higher rates of physical activity, food diary use and self-monitoring of weight than those in the resources-only group, while also having higher Weight Watchers enrollment (83.4% vs. 61.2%).

Ladapo and colleagues reported that the mean incentives earned by the goal-directed group was $440.44, while the outcome-based incentive group earned a mean of $303.56.

The researchers pointed out that despite higher program enrollment and participation, total weight loss of the goal-directed group at 6 months was comparable to the outcome-based group.

“The reasons are unclear but may relate to differences in patient response to incentives that directly target a 5% weight loss outcome, in contrast to incentives that indirectly target the same outcome by incentivizing evidence-based activities in the outcome’s pathway,” they wrote.

The researchers also reported that financial incentives did not reduce intrinsic motivation for weight loss or self-monitoring, or improve financial well-being for participants, the latter finding Ladapo and colleagues reasoned could be fixed by providing considerably larger incentives for those in low-income neighborhoods.

The researchers concluded that both goal-directed and outcome-based strategies were more effective in weight reduction than resources only, while noting the amount of weight lost by participants “was substantial, including patients in the resources-only group.”

“Future work should address cost-effectiveness of these strategies, long-term outcomes, and effectiveness when disseminated to clinical and community settings outside of clinical trials,” they wrote.

References:

• Financial incentives boost weight-loss programs. https://www.sciencedaily.com/releases/2022/12/221205121556.htm. Published Dec. 5, 2022. Accessed Dec. 6, 2022.
• Ladapo J, et al. JAMA Intern Med. 2022;doi:10.1001/jamainternmed.2022.5618.