Group-based incentives may produce more weight loss

Employees offered financial incentives to lose weight may drop more pounds when they're competing as part of a group of colleagues, a new study suggests.

Researchers compared two incentive scenarios. Under one, employees got $100 for each month they met the goal of dropping at least one pound per week. Under the second scenario, $500 was set aside each month for a group of five co-workers and the ones who met their goal got to split the prize.

"People may be more motivated to achieve a particular goal when a particular resource that had been allocated for them is given to someone else if they don't achieve their goal," said Dr. Jeffrey Kullgren, the study's lead author from the University of Michigan Medical School and the Ann Arbor VA Healthcare System.

He and his colleagues randomly assigned 105 obese hospital employees to be offered the individual incentive, the group-based incentive (without knowing who else was in their group) or not to receive any reward for losing weight.

Participants weighed-in each month for about five months. By the end of the study, people in the no-reward group had lost an average of just over one pound each. Those who were offered individual incentives had shed 3.7 pounds, on average, compared to 10.6 pounds among those with group-based incentives.

The possibility of earning more than $100 if their group members didn't lose weight, in addition to the element of competition, may have driven those employees to make the most significant changes, Kullgren's team reported Monday in the Annals of Internal Medicine.

What works best?

Although weight-loss incentives are becoming popular with many employers, researchers said there are still questions about what type of program provides the most bang for the buck.

"There are hundreds of different ways you can think about doing it. I don't think there's a consensus about what the best way is," said Robert Jeffery, who has studied financial incentives at the University of Minnesota in Minneapolis.

Past research does provide a few clues, however, he told Reuters Health. Rewarding people more frequently - such as every week - seems to encourage more weight loss, as does offering more money for success, not surprisingly.

Behavioral economics suggests that aversion to losing - whether money or just a competition with other members of the group - can be a good motivator.

For instance, one recent study found loss aversion played a role in who lost weight when dieters had to deposit a few dollars into an account weekly, and the cash was matched if they lost weight or forfeited if they didn't.

Still, even effective programs can lose their "oomph" over time, according to Jeffery, who wasn't involved in the new research.

And most studies don't account for the odds that people who would be trying to lose weight anyway are the most likely to join a financial incentives program - and certain other heavy employees might be harder to reach, he said.

There are still many strategies to explore, Jeffery added - such as paying people more, the longer they keep the extra weight off.

Some employers have also tried "Biggest Loser"-style games, but those may discourage certain people because only the few who lose the most weight get rewarded, researchers pointed out.

"This is yet another approach that we need to have in our tool kits for addressing this really major and vexing public health problem," Kullgren told Reuters Health, adding that an incentive program could be combined with diet and exercise counseling, for example.

The question is, "How can these types of approaches complement what we already know works?" he said.