Optimizing Dietary Adherence in a Mobile Behavioral Weight Loss Intervention for Adults

Inclusion Criteria

Inclusion Criteria: * BMI 25-50 kg/m2 at baseline * Own a smartphone with an active data and text messaging plan * English-speaking and writing * Willing to be randomized to any of the additional treatment components Exclusion Criteria: * Lost 5% or more of body weight (and kept it off) in the last 3 months * Past diagnosis of or receiving treatment for a clinically diagnosed eating disorder (anorexia nervosa or bulimia nervosa) * Current symptoms of alcohol or substance dependence * Currently pregnant, pregnant within the past 6 months, currently breastfeeding, or planning to become pregnant within the next 6 months * Untreated thyroid disease or any changes (type or dose) in thyroid medication in the last 6 months * Hospitalization for depression or other psychiatric disorders within the past 12 months * History of psychotic disorder or bipolar disorder * Currently participating in a weight loss, nutrition, or physical activity study or program or other study that would interfere with this study * Currently using prescription medications with known effects on appetite or weight (e.g., oral steroids, weight loss medications), except individuals on a stable dose of SSRIs for 3 months * Current use of bone acting medications (e.g., raloxifene, calcitonin, parathyroid hormone during the past year, PTH-analogues \[e.g., teriparatide, abaloparatide\], sclerostin inhibitors (romosozumbab), RANK ligand inhibitors (denosumab) or bisphosphonates during the last two years * 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) * Report a health condition for which the program's dietary and physical activity recommendations would be unsafe, including hospitalization for heart failure, myocardial infarction or stroke in the past year, chronic kidney disease stage IV or V, liver failure or cirrhosis, chronic obstructive pulmonary disease on oxygen or requiring steroids, osteoporosis on medication, sarcopenia, history of fragility fractures, or dementia * Other health problems that may influence the ability to walk for physical activity or be associated with unintentional weight change, including current cancer diagnosis, cancer treatment within the past 5 years or tuberculosis * Previous surgical procedure for weight loss or planned weight loss surgery in the next year * Another member of the household is a participant or staff member on this trial * Ability to provide consent (4 items adapted from the UBACC \[University of California, San Diego Brief Assessment of Capacity to Consent\]) * Reason to suspect that the participant would not adhere to the study intervention * Does not live in the United States * Cannot have participated in a research study conducted by UNC Weight Research Program in the past 2 years Individuals endorsing joint problems, current treatment for hypertension or hyperlipidemia, or osteoporosis diagnosis not on medication will be required to obtain written physician consent to participate.