Paying obese people cash to lose a certain amount of weight or complete weight-loss activities works better than offering independent free tools like weight loss programs, diet books, and wearable fitness trackers, according to a new study.
The study, led by researchers at NYU Grossman School of Medicine, followed 668 low-income individuals, mostly Hispanic men and women, with an average weight of 218 pounds to begin the trial, for up to one year of weight loss efforts. All were randomly assigned to receive one of three sets of incentives over six months, including those who received cash and none.
Publish in the journal JAMA Internal Medicine 5, results showed that offering study participants an average of $440 in direct cash in total to lose at least 5% of their original body weight (about 10 pounds) is most effective in the short term. Forty-nine percent of those offered cash lost this amount of weight after six months. That number dropped to just 41% after a full year of follow-up.
Similarly, paying other study volunteers an average of $303 for the initial study period to meet weight loss goals, such as attending at least two weight loss counseling courses each month, being weighed at least three times a week, or exercising for at least some time. 75 minutes a week was also effective. About 39% of this study participants lost 5% of their baseline weight after six months, and about 42% lost the minimum amount of weight after 12 months of follow-up.
All study participants received a free one-year voucher for the Weight Watchers program, which includes classes, counseling, and weight loss tips. Wearable fitness devices (Fitbits), digital scales, and meal diaries were also provided so that experimental volunteers could track their weight during and after the study.
One-fifth of those who received zero financial incentives and were offered only free vehicles lost a minimum of weight after six months. However, this increased to almost a third a year later.
“Our study provides solid evidence that offering incentives, particularly cash rewards, even for just six months, helps people with limited means who are struggling with obesity lose weight,” says senior researcher Melanie Jay, an associate professor in the department. Department of Medicine and Population Health at NYU Langone Health. “However, any incentive to lose weight can work, even if it just offers tools to help you do it.”
Jay warns that while the study results show a short-term benefit, more research is needed to see if these weight losses persist for many years and whether any periodic “boosting” incentives are needed to maintain the reductions over the long term.
Also, incentives linked to actual weight loss performed better in the short term, while incentives linked to weight loss goals stabilized after one year. Jay says this shows that goal-oriented financial rewards can outlast others in the long run. He says more research is needed across more diverse groups, where obesity is an issue for many, not just urban Hispanics living with obesity. Such groups include Blacks, Native Americans, and United States military veterans who have been determined by federal health agencies to be disproportionately affected by obesity.
Interventions needed to address persistent obesity epidemic in the US National reports estimate that more than 40 percent of American adults are obese; this is defined as those with a body mass index or BMI over 30, which is a measure of height and weight.
“New tools are needed beyond encouragement and education to help some people struggling with obesity,” says Jay, who also serves as director of NYU Langone’s Obesity Comprehensive Program. “There is no single solution to America’s worsening weight problem. Our national approach is type 2 diabetes, heart disease, and some cancers.”
For the study, which ran from November 2017 to May 2021, the researchers enrolled volunteers from hospital-based clinics in New York City and Los Angeles, where diet, exercise routine, and weight loss could be easily tracked with monthly visits. Participants ranged in age from 18 to 70, and all came from neighborhoods with an average income of less than $40,000. For those who received cash incentives, payments were made monthly as weight was lost or targets were met.
Funding support for the study was provided by National Institutes of Health grants R01MD011544 and UL1TR001445.
Besides Jay, other NYU Langone research investigators include: Stephanie Orstad, PhD; Christina Hernandez, MPH; Susan Parraga, BS; Victoria Ter, MA; Sandra Wittleder, PhD; and Andrew Wallach, MD. Other researchers include study lead researcher Joseph Ladapo, MD, PhD, at the University of Florida at Gainesville; and study co-investigators Soma Wali, MD; Chi-Hong Tseng, PhD; Un Young Rebecca Chung, BS; Miguel Cuevas, Bachelor; Robert Ponce, Bachelor; and Noah Goldstein, PhD, of UCLA in Los Angeles; Judith Wylie-Rosett, EdD, RD of the Albert Einstein College of Medicine in the Bronx, NY; and Suzanne Shu, PhD, Cornell University, Ithaca, NY