This randomized clinical trial of weight loss treatment will examine if adding personalized, one-on-one treatment session to standard behavioral group treatment will result in greater weight loss, less weight regain after weight loss, and better adherence to the treatment protocol.

Everyone who enrolls in the study will receive information on healthy eating, how to increase their physical activity and develop healthy exercise habits and ways to change their eating so that they will lose weight. This information will be provided at evening group sessions. There will be a total of 20 group meetings over an 18-month period that will be held:

• every week during the first month of the study,
• every other week for the second month
• once a month for months 3-12
• every 6 weeks for months 13-18

Participants in the self-efficacy group will also be asked to participate in one-on-one lifestyle counseling sessions with a study interventionist throughout the study.

Everyone will be asked to complete questionnaires, two 24-hour dietary recalls over the phone, and have blood tests done every six months (at the beginning of the study, at 6, 12, and 18 months) a total of 4 times for the study.

Inclusion Criteria:

• age 18 years or older
• BMI > 27 and < 43
• willing to be randomized to one of the two treatment conditions
• successful completion of screening requiring 5-day recording of food intake in a paper diary
• have at least two risk factors for coronary heart disease, e.g., overweight or obese, hypertension, dyslipidemia, positive family history (first degree relative)

NOTE: Although residing in Western Pennsylvania is not an explicit eligibility criterion, participants are asked to travel to the University of Pittsburgh frequently (weekly for the first month)

Exclusion Criteria:

• presence of a current serious illness or unstable condition requiring physician-supervised diet and exercise (e.g., diabetes, recent acute myocardial infarction) for which physician supervision of diet and physical activity prescription is needed
• physical limitations precluding ability to engage in physical activity at moderate intensity
• pregnancy or intention to become pregnant in the next 18 months
• current treatment for a psychological disorder
• reported alcohol intake > 4 drinks/day
• previous participation in a formal weight loss program within the past 5 years, e.g., Weight Watchers or a research program, or current use of weight loss medication
• planned extended vacations, absences, or relocation within the next 18 months