Small Cash Rewards for Big Losers – Experimental Insights Into the Fight Against the Obesity Epidemic

We complement the empirical evidence on the sustainability of weight loss achieved through cash rewards and, for the first time, rigorously examine the potential of cash rewards to prevent weight cycling. In a three period randomized controlled trial, about 700 obese persons were first assigned to two treatment groups, which were promised cash contingent on the achievement of an individually assigned target weight, and to a control group. Successful participants were subsequently allocated to two treatment groups offered cash rewards for confirming the previously achieved target weight and to a control group. This is the first experiment of this kind that finds effects of weight loss rewards up to 18 months after they were removed. Additional rewards only significantly improve the sustainability of weight loss while they are in place.