Ninety-six obese adults (BMI 30–39.9 kg/m2) will be randomized to one of three treatment
conditions: (1) standard behavioral weight loss (STND), (2) technology-supported behavioral weight loss (TECH); or(3) self-guided behavioral weight loss (SELF). All groups will aim to achieve a 7% weight loss goal by reducingcalorie and fat intake and progressively increasing moderate intensity physical activity to 175 minutes/week. STNDand TECH will attend 8 group sessions and receive regular coaching calls during the first 6 months of the intervention; SELF will receive the Group Lifestyle Balance Program DVD’s and will not receive coaching calls. During months 1–6, TECH will use a specially designed smartphone application to monitor dietary intake, body
weight, and objectively measured physical activity (obtained from a Blue-tooth enabled accelerometer). STND and
SELF will self-monitor on paper diaries. Linear mixed modeling will be used to examine group differences on
weight loss at months 3, 6, and 12. Self-monitoring adherence and diet and activity goal attainment will be tested
as mediators.