Overweight and obese adults recruited from the primary care setting (n=150) will be enrolled in a 6-month randomized trial of the INTERVENTION versus CONTROL. Both groups will receive usual medical care, printed materials, and educational text messages. The INTERVENTION group will also receive personalized coaching and feedback, as well as peer support, via text message.

The investigators hypothesize that compared to those in the Control group, patients in the Intervention group will lose more weight and demonstrate more favorable changes in fruit and vegetable intake, exercise, and social support for weight loss.

Inclusion Criteria:

• Approved to participate by PCP (Patients with diabetes, hypertension, or dyslipidemia will be eligible if approved by their PCP)
• Age ≥ 21 years
• Body mass index (BMI) 25 to 45 kg/m2 and weight ≤ 400 pounds
• Goal of losing weight (not just maintain weight)
• Willing to change diet, physical activity in order to lose weight.
• Currently uses text messaging in English on mobile phone
• Willing to use send and receive text messages for this study without direct compensation for cost of messages (general compensation for study participation will be provided)
• Have a scale at home for self-monitoring weight
• Fluent in English (speak, read, write)
• Commit to return for follow-up weight at 6 months regardless of amount of weight lost

Exclusion Criteria:

• Involuntary or voluntary weight loss of ≥ 5% body weight in previous 6 months

• Participating in research project involving weight loss, exercise, or dietary modification in the previous 6 months

• Any of the following medical conditions which could affect weight or for which weight loss is contraindicated

  • End-stage liver disease
  • End-stage kidney disease
  • Cancer within previous 2 years (except non-melanoma skin cancer)

• Myocardial infarction, stroke, or transient ischemic attack within previous 6 months

• Unstable angina

• Severe arthritis or other medical conditions which would prevent brisk walking

• Schizophrenia

• Hospitalization for psychiatric problems during the prior 12 months.

• Current use or anticipated future use (during 6 month study) of medications that could cause weight loss:

  • phentermine
  • orlistat (prescription Xenical or OTC Alli)
  • topiramate
  • buprioprion
  • exenatide (Byetta)
  • liraglutide (Victoza)

• Prior bariatric surgery or plans for bariatric surgery in next 6 months

• Pregnant or breast feeding within the previous 6 months

• Planning to become pregnant in next 6 months

• Consumes > 14 alcoholic drinks per week

• Current use of illicit drugs

• Planning to move out of the area in the next 6 months

• Another member of household or a close contact is participating in the study