The purpose of this study is to conduct a randomized controlled trial to compare the weight losses produced by the Weight Watchers Online program revised for 2015 (WWO2015) and WWO2015 plus the provision of an electronic scale and weekly email feedback on weight loss (WWO2015 Enhanced), over a 6-month period.

Inclusion Criteria:

• Age 18-70 years
• Body mass index (BMI) between 27 and 40 kg/m2
• Both genders will be recruited; At least 10% of participants will be men. Enrollment of women will be capped at n = 324 (90%) to meet this goal.
• All ethnic groups will be recruited, with a goal of recruiting 10% minorities
• English speaking
• Have access to the Internet via a computer, and basic computer skills

Exclusion Criteria:

• Report health problems that make weight loss or unsupervised exercise unsafe or unreasonable
• Report a heart condition, chest pain during periods of activity or rest, or loss of consciousness on the Physical Activity Readiness Questionnaire1
• Are currently pregnant or breastfeeding, or intend to become pregnant in the next 12 months
• Are planning to move outside of the state within the next 12 months
• Report any cognitive or physical limitations that preclude use of a personal computer
• Have participated in a study conducted by the WCDRC or UT in the past 2 years
• Have followed a commercial weight-loss program within the previous 6 months or who are currently following a commercial weight loss program
• Weight loss of ≥ 5% of initial body weight in the last 6 months
• History of clinically diagnosed eating disorder excluding Binge Eating Disorder.
• Previous surgical procedure for weight loss
• Currently taking weight loss medication
• Treatment of cancer within the last 6 months