This study will evaluate the main effects of daily vs. weekly feedback and contingent vs. non-contingent incentives for increasing walking behavior among overweight and obese adults.

Approximately 68% of adults are overweight or obese, which is associated with increased risk for health conditions, including cardiovascular disease, type 2 diabetes, and cancer. These individuals are more often sedentary than the general population, which compounds the risk for these same conditions. While the benefits of engaging in physical activity are well-established, few individuals are able to successfully increase activity to recommended levels. Existing intervention programs, often derived from theories such as social cognitive theory or related theories, have had limited success. Behavioral economics offers a promising alternative, suggesting that engagement in any behavior is based on the maximizing utility and happiness (i.e., weighing the cost and benefit of the behavior). Interventions based on this theory aim to increase the immediate benefit of engaging in physical activity, often using a financial incentive.

This study will last for 8 weeks. All participants will have the use of a FitBit for ongoing self-monitoring and a personalized step-count goal designed to help increase daily steps. Participants will receive feedback on reaching their goals either daily or weekly.

Inclusion Criteria:

• 25 kg/m2 ≤ BMI ≤ 45 kg/m2
• Age 18-70
• Currently inactive (engages in less than 6,000 steps/day on at least 4 of 7 days per week OR engaged in less than 10,000 steps /day on at least 5/7 days per week, confirmed by FitBit at baseline)
• Able to engage in moderate amount of walking
• Able to receive email/text messages from study staff

Exclusion Criteria:

• Psychiatric conditions that would make it difficult to comply
• Medical conditions that would make it difficult to comply