Project Background: Behavioral economics suggests that the chronic inability to make the daily behavioral changes that can help us lose weight may be the result of "present bias," which is a tendency to value small, immediate rewards over large rewards in the distant future. For many of us, the immediate gratification of eating an unhealthy food is a more powerful motivator than is the elusive dissatisfaction of the long-run health consequences of an unhealthy diet. Patient rewards may overcome present bias by moving the rewards for healthy behaviors forward in time. In a patient reward program, patients are given tangible, timely rewards for achieving specific health goals, such as losing one pound per week over 16 weeks. Meta analyses of randomized trials have found that rewards for weight loss are effective during the reward period, but the weight loss was not sustained after the reward was removed. Thus, the key challenge to a reward program is not achieving weight loss, but maintaining it. The proposed study tests the hypothesis that the significant weight regain found in prior reward trials can be attributed to use of financial rewards-e.g., cash or the equivalent of cash-in those trials. Experiments in behavioral economics have found that providing participants with financial rewards for participating in a study invokes behavior defined by reciprocity-the effort the participants gave in the study was proportional to the amount of money that they were given. When participants were given non-financial rewards, they exhibited no reciprocity-the effort was consistently high and did not vary with the quantity of the non-financial reward. By using financial rewards, prior trials may have invoked money-market norms of reciprocity, such that patients' efforts toward weight loss were high when rewards were offered, and reduced when they were discontinued. The investigators hypothesize that non-financial rewards, like tickets to a Seattle Mariners baseball game, will not invoke reciprocity or the consequent weight regain.