Inclusion Criteria:  body mass index (BMI) of 25-40 kg/m^2 English-speaking and writing own a smartphone with a data and text messaging plan not adhering to the American College of Sports Medicine's recommendation of at least 150 minutes/week of moderate-to-vigorous intensity activity willing to be randomized to any levels of the factors  Exclusion Criteria:  Type 1 diabetes or currently receiving medical treatment for Type 2 diabetes Other health problems which may influence the ability to walk for physical activity or be associated with unintentional weight change, including cancer treatment within the past 5 years or tuberculosis Report a heart condition, chest pain during periods of activity or rest, or loss of consciousness on the Physical Activity Readiness Questionnaire (PAR-Q; items 1-4) Lost 10 or more pounds (and kept it off) in the last 6 months Currently taking weight loss medications Report a past diagnosis of or current treatment for a DSM-V (Diagnostic and Statistical Manual 5) eating disorder (anorexia nervosa or bulimia nervosa) Currently pregnant, pregnant within the past 6 months, or planning to become pregnant within the next 6 months Hospitalization for depression or other psychiatric disorder within the past 12 months History of psychotic disorder or bipolar disorder Another member of the household is a participant or staff member on this trial Currently participating in a weight loss, nutrition or physical activity study or program or other study that would interfere with this study