Dieting for Dollars

Abstract & Commentary

By Barbara A. Phillips, MD, MSPH, Professor of Medicine, University of Kentucky; Director, Sleep Disorders Center, Samaritan Hospital, Lexington. Dr. Phillips reports no financial relationship to this field of study.

Synopsis: Overweight employees who are paid to lose weight will do so in proportion to how much and how soon they are paid.

Source: Finkelstein EA, et al. JOEM. 2007;49:981-989.

This was a prospective, randomized study of 3 matched groups of overweight workers who were recruited from North Carolina colleges by email, letters, and flyers. Internet access was required to participate in order to fill out surveys and undergo initial screening. Overall, the 201 participants had a mean BMI of 33 kg/m2, 89% were white, a majority were between 35 and 54 years old, and 76% were women. The participants were divided into three groups for the first 3 months: those who were encouraged to lose weight and received no immediate financial incentive, but were paid $14 for each percentage point of weight lost at 6 months; those who received $14 for each percentage point of weight lost from baseline to three months but no further incentive at 6 months, and those who received $7 for each percentage point of weight loss from baseline at baseline and another $7 for each further percentage point of weight lost at 6 months. Thus, at the end of the 6 month study period, payments were essentially equalized, so that all participants were able to earn $14 for each percentage of weight loss from baseline at either 3 or 6 months. For example, even if a person were in the group that received no payment for weight lost at 3 months, he/she could be paid $14 per percentage point weight loss at 6 months. In addition, everyone received $5 for attending the 3 month and the 6 month weigh-ins.

At the first weigh-in (3 months) those who were paid the most in the shortest time frame ($14 per percentage lost in the first 3 months) lost the most weight: an average of 4.7 pounds. They were also more likely to attend the weigh-in, and to have lost 5% of their initial weight at 3 months. Those who were paid $7 per percentage point lost an average of 3 pounds and those who were not scheduled to get paid until 6 months had only lost 2 pounds at three months. At 6 months, the biggest differences were in attrition from the study! A third of those who were paid $7 at each weigh-in had dropped out, compared with about half of those in either the deferred payment (54%) or early payment (45%) groups. Thus, analysis of the final results was hampered by the fact that only slightly more than half the participants still remained in the study. At 6 months (largely because of attrition) average weight loss between groups and the likelihood of achieving a 5% weight loss were not statistically different between groups, using an intention-to-treat approach. Try as I might, I was unable to tell from this paper if the group that was paid earliest was able to maintain the weight loss. However, those who were heavier to begin with lost the most weight, and those in the North Carolina University system lost more weight than those in the North Carolina Community College system. Non-whites were more likely to attend both weigh-ins than whites were, and the authors speculated that the modest financial incentives offered in this study might have represented a larger relative financial inducement to those with lower incomes. In their discussion, they note that the average payout at 3 months to those who were paid the highest amount at the shortest time period was $35 per subject. The authors concluded that "modest financial incentives can be effective in motivating overweight employees to lose weight."

Commentary

Like many other medical articles about weight loss, this one received some play in the lay press ("Dollars help workers shed pounds."1) Given our persistent obesity epidemic despite intense study and efforts to address it, consideration of innovative approaches to weight loss seems reasonable. Several investigators have already explored linking financial rewards to weight loss in the context of weight loss programs,1-4 but they have generally evaluated the effect of losing a financial deposit, rather than gaining "new" money for weight loss. The current paper breaks new ground, because it addresses the impact of the timing and amount of payment on weight loss in a worksite as a stand-alone (not as part of a weight loss program) intervention. It reminds me of the joke whose punch line is: "We have already established that. NOW we are just haggling." Some people will lose weight if paid to do so, and the current study suggests that the more money and the more quickly they are paid, the more likely they are to do so (duh). There are many remaining questions, not the least of which is whether workers can maintain weight loss in such a program, and whether it is ethical to reward people for getting unhealthy in the first place.

One of the most important questions is how to apply these findings to our daily clinical practice. Obese patients might benefit from rewards for weight loss. At the very least, we can notice this and compliment them. We can encourage their partners and significant others to reward them. And maybe they can set up internal inducements for themselves.

References

1. Lexington Herald-Leader, Tuesday, Sept 25, 2007.

2. Jeffery RW, et al. Behav Res Ther. 1978;16:363-369.

3. Kane RL, et al. Am J Prev Med. 2004;27:327-352.

4. Jeffery RW, et al. Behav Ther. 1984;15:273-279.