The purpose of the study is to conduct a randomized clinical trial examining the feasibility and effectiveness of two guided self-help behavioral weight loss (gshBWL) treatments delivered via the internet for individuals struggling with weight loss one year following bariatric surgery. The two treatments will consist of 1) gshBWL delivered through the internet only (gshBWL-I) and 2) gshBWL delivered via the internet with additional complementary phone sessions (gshBWL-IP).

Inclusion Criteria:

• gastric bypass and sleeve surgery patients from Yale's Bariatric/Gastrointestinal Surgery Program
• surgery 1-2 years prior
• <60% excess weight loss
• able to read English proficiently enough to read the patient self-help materials and study assessments
• available for the duration of the treatment
• availability of internet and phone to participate in study interventions
• agree to the study procedures

Exclusion Criteria:

• medical status judged by the surgeon as contraindication (rare instances of need for additional surgery or medical instability)
• unable to ambulate
• current medications that influence eating/weight
• current substance dependence or other severe psychiatric disturbance (e.g., suicidality) that requires immediate treatment.