Can We Combat the Obesity Crisis by Paying People to Lose Weight?

A provocative study explores the effectiveness of rewarding weight loss, but raises questions of ethics and equity.

By Andrew Feld

The number of people with obesity in the United States continues to climb each year. In addition to its well-documented health risks — higher risk of cancer, type II diabetes, and stroke — obesity also imposes a huge financial burden. According to the CDC, obesity costs the U.S.’s already expensive and fragile healthcare system  $173 billion annually. 

Causes of the obesity epidemic are complex, so researchers are investigating a wide range of solutions, including financial incentives: simply, paying people to lose weight.  

A recent study, in JAMA Internal Medicine, published by researchers from Florida, California, and New York, investigated whether this approach can work. They divided participants into three groups and promised two of the groups financial rewards based on how well they hit certain benchmarks while losing a certain percentage of their body weight. 

And, they found, this approach worked:  People in both groups promised financial rewards lost weight — and though their benchmarks were different, the amounts of weight lost by each group were strikingly close.

“Our main finding is that both financial incentive arms lost more weight than the control group who just got the resources without the financial incentive,” said Dr. Melanie Jay, lead researcher and professor of population health at New York University. “And that we did not see such differences between the goal-directed and the outcomes based on our main outcome, which was six months.”

The randomized clinical trial was conducted from November 2017 to May 2021 and included 668 individuals from three different hospitals in New York City, New York, and Los Angeles. All participants lived in lower-income neighborhoods and maintained a Body Mass Index over 30. 

Researchers then randomly placed participants into one of three groups: resources-only, outcome-based, and goal-directed. Participants in all groups received a free one-year membership to Weight Watchers, a food journal, a digital scale, and a Fitbit. They were also provided information on how to utilize those resources, such as being told to weigh themselves three times a week and exercise for 75 minutes per week. 

Participants in the outcome-based and goal-directed groups could also earn money for achieving specific objectives. In the outcome group, individuals were paid monthly if they lost greater than 2.5 percent of their original body weight. However, losing more than 2.5 percent led to higher payouts — all the way up to a $750 cap for the duration of the six-month study. People in the goal-directed group could also earn a maximum of $750. Attending at least half of the weekly weight management sessions netted them $450 while keeping a food diary and exercising with their Fitbit earned them even more.

Researchers mainly wanted to see what impact these financial incentives had on the percentage of people that ended up losing more than 5 percent of their baseline weight. In the end, they found those percentages to be 22.1 percent in the resources-only group, 49.1 percent in the outcome-based group, and 39 percent in the goal-directed. Participants in both financial groups also significantly reduced their waist circumference in comparison to those in the resources-only group.

“I’m not surprised” at the results, said Dr. Christina Gavegnano, a bioethicist and professor of drug discovery at Emory University. “Because when you pay someone to do something, typically humans will do it better. There’s more incentive. And if you said to me, ‘I’ll pay you to be in the study to do that,’ I might try harder.” 

It’s difficult to know if “trying harder” is the reason people in the financial incentives groups lost more weight, but the data is pretty straightforward. Take away the gap between the two financial incentives groups, which is not significant considering the average weight loss between the two differs by only 0.32 kilograms, and the study clearly shows that paying people to lose weight works, at least in the short term. 

The concept that people respond to incentives is nothing new — in fact, it forms the backbone of the field of behavioral economics. The view also guides certain policy decisions. For example, MetLife, one of the largest life insurance companies in the world, charges higher premiums the more overweight someone is. As an individual’s weight goes up, so too do their premiums. And as that same individual’s weight goes down, their premiums decrease. Essentially, MetLife is paying people to lose weight. 

But is this ethical? After all, people with a lower socioeconomic status may decide to lose weight not because they truly want to, but because they fiscally need to. 

“From a biomedical perspective paying people to lose weight is not intrinsically wrong if it is paired with informed consent, has a potential benefit, as well as doesn’t cause harm to the person,” said Gavegnano. “But, I also think on a greater picture, paying people to lose weight without actually solving the underlying problem doesn’t actually solve the problem.”

Gavegnano’s final point raises an interesting question. What happens when an individual loses all the weight they need to and the financial rewards stop? Without easy access to healthy foods or an exercise space, people may regain the weight they had previously lost. While Dr. Jay’s study only looked at the results of financial incentives for losing weight, she wants future studies to look at paying people to keep their weight in a healthy range. 

“What happens for weight maintenance,” Jay said. “So now that patients have lost weight, can you incentivize weight maintenance to keep the weight off? Because it actually takes a lot of work.”

A lot of work is right. While financial incentives are not literally a diet, they do act as an intermediary, motivating people to diet. And with diets, unfortunately, The Cleveland Clinic estimates that 80-95% of people regain the weight that they worked so hard to lose. 

However, for people to maintain a healthy weight, they first need to get there. And for now, implementing financial incentives for weight loss can play a role in helping individuals live healthier and more enjoyable lives while also reducing the U.S.’s healthcare costs. 

“To lose weight via lifestyle you need to overcome all the barriers to do that and all the hunger that happens when you start to lose weight when your ghrelin goes up,” said Jay. “ So you need a lot of motivation. And if the financial incentives can help with that, I think that could be one of the tools in our toolkit.”