The ENGAGED study is a 12-month randomized controlled trial investigating different strategies to improve weight loss in overweight individuals. All participants will receive an effective weight loss treatment: either self-guided or group formats. All treatment will be provided in the Department of Preventive Medicine at Northwestern University. Participants who receive the self-guided weight loss treatment will be provided with a weight loss manual that contains proven behavioral weight loss strategies. Those participants who receive the group treatment will take part in 8 weekly, 90 minute group sessions in our clinic at 680 N. Lakeshore Dr., Chicago, IL 60048. Some participants will also be assigned an individual coach, who will communicate with them regularly via phone, email, and/or text message for the duration of the study. All participants must be willing and able to record food and beverage intake (either on a smartphone or on paper) and be willing to wear a small and unobtrusive physical activity measurement device for the first six-months of the study. Additionally, all participants will be asked to attend 3 follow-up assessment visits at our clinic at months 3, 6 and 12 after the study begins. Participants will be compensated for completing each of the 3 follow-up assessments. All participants will be part of a team weight loss competition at 3 and 6 months with financial incentive to be split evenly among the winning team.

The Diabetes Prevention Program (DPP) intensive lifestyle intervention is the gold standard weight loss treatment for adults with cardiometabolic risk factors. Despite its efficacy, the DPP has not been widely adopted, because its 16 individual, face-to-face sessions with a specialist are considered too burdensome and expensive to be a sustainable program. Attempts to reduce cost by decreasing session number have yielded greatly diminished weight loss. Behavioral adherence to diet and activity goals declines and weight regain routinely begins once frequent face-to-face meetings cease. The still unmet challenge of DPP implementation is how to reduce treatment intensity without excising the regular social support, accountability, and feedback that are essential to maintain adherence. We hypothesize that it is feasible to implement DPP Intensive Lifestyle Treatment as effectively but twice as efficiently by using hand held technology to preserve feedback, accountability, and regular social support. The smartphone-based technology system to be tested is guided by Carver and Scheier's control systems theory of self-regulation. Initial formative research will upgrade the smartphone with engaging features that motivate participants to use the device to self-monitor and interact with a coach and peer support group. Use of the finalized tool will be compared to usual recording on paper records in a preliminary 3-group randomized controlled trial (RCT) involving 96 obese adults. By enabling peer support, accountability, and feedback on diet, physical activity, and weight loss goals continuously through the 6-month intervention period, the ENGAGED system is expected to enhance (1) behavioral adherence [operationalized by (a) self-monitoring of diet and activity and (b) attainment of diet and activity goals], and (2) weight loss. An enabling technology that integrates specialist and peer support resources to improve treatment adherence could help to curtail the obesity epidemic by increasing the efficiency, feasibility, and reach of effective DPP lifestyle intervention.

Inclusion Criteria:

• BMI between 30-40
• weight stable (not gained/lost more than 25 lbs in the past 6 months)
• not enrolled in any formal weight-loss program
• interested in losing weight
• willing and able to record dietary intake and weight for 6 months and wear an accelerometer
• willing to attend 8 weekly groups and 2 follow up assessments at the Northwestern Chicago campus
• expect to reside in the Chicago land area for the next 12 months

Exclusion Criteria:

• any unstable medical conditions (i.e. uncontrolled hypertension, diabetes, unstable angina pectoris, myocardial infarction, transient ischemic attack, cancer undergoing active treatment, a cerebrovascular accident within the past 6 months)
• history of insulin-dependent diabetes
• Crohn's disease
• diagnosis of obstructive sleep apnea requiring intervention
• required use of an assistive device for mobility (i.e. cane, wheelchair)
• BMI > 40
• hospitalization for a psychiatric disorder within the past 5 years
• those at risk for adverse cardiovascular events with moderate intensity activity
• those currently taking weight loss medication or committed to following an incompatible dietary regimen
• women who are pregnant, trying to get pregnant, or lactating
• Bulimia Nervosa
• suicide ideation
• current binge eating disorder
• those currently taking medications known to cause weight gain (i.e. Prednisone, Depakote, Diebeta, Diabinese, Cardura, Inderal, Zyprexa)
• current substance abuse or dependence
• plantar fasciitis
• current substance and/or alcohol dependence
• depression
• ADHD