Participants: Inclusion criteria consists of: a) age: 21 to 65 years, b) overweight or obese status: BMI between 25.0 and 39.9, c) regular access to the Internet, d) own and regularly use a cell phone and know how to use SMS, d) ability to read and speak English, and e) ability to participate in moderate PA. Exclusion criteria consists of a) current pregnancy or the intention of becoming pregnant during the 12 month trial, b) moving out of the country during the 12 month trial, and c) current eating disorder.