COMPARISON OF BEHAVIORALLY-BASED REMOTE APPROACHES TO OPTIMIZE WEIGHT LOSS AND IDENTIFICATION OF FACTORS WHICH CHARACTERIZE TREATMENT RESPONSE - PROJECT SUMMARY IN-PERSON BEHAVIORAL WEIGHT LOSS (WL) PROGRAMS ARE THE GOLD STANDARD OF OBESITY TREATMENT, BUT REMOTE-BASED INTERVENTIONS ARE BECOMING INCREASINGLY UTILIZED AS THEY OVERCOME BARRIERS COMMON TO IN-PERSON PROGRAMS (E.G., GEOGRAPHICAL, TIME, AND TRAVEL CONSTRAINTS) AND REPRESENT A MORE TRANSLATABLE INTERVENTION MODEL. YET, REMOTE WL INTERVENTIONS CAN VARY SUBSTANTIALLY, AND QUESTIONS REMAIN REGARDING WHICH TYPE IS MOST EFFECTIVE AND WHETHER THERE ARE CERTAIN GROUPS OF INDIVIDUALS WHO RESPOND BEST TO ONE TYPE OVER ANOTHER. FOR EXAMPLE, OUR FULLY AUTOMATED, ONLINE PROGRAM PRODUCES A 4.5% WL ON AVERAGE AND ABOUT HALF OF PARTICIPANTS ACHIEVE A WL 5%. WHILE THIS LOW-TOUCH INTERVENTION IS EFFECTIVE FOR MANY, OTHERS HAVE LIMITED SUCCESS AND MAY BENEFIT FROM A DIFFERENT TYPE OF REMOTE INTERVENTION (E.G., GROUP-BASED VIDEOCONFERENCE PROGRAM, RESEMBLING IN-PERSON TREATMENT) OR MORE INDIVIDUAL SUPPORT (E.G., VIA COACHING). THIS TRIAL UTILIZES A 2X2 FACTORIAL DESIGN TO COMPARE TWO REMOTE-DELIVERY FORMATS (AUTOMATED ONLINE PROGRAM VS. GROUP-BASED VIDEOCONFERENCE PROGRAM) AND THE ADDED EFFECT OF COACHING (VS. NO COACHING) ON 12-MONTH WL. DIRECT COMPARISONS OF THESE APPROACHES HAVE BEEN LIMITED. FROM A PERSONALIZED MEDICINE PERSPECTIVE, IT IS ALSO IMPORTANT TO UNDERSTAND FOR WHOM EACH REMOTE APPROACH SHOULD BE RECOMMENDED. THUS, AN ADDITIONAL AIM IS TO DEVELOP TWO ALGORITHMS WHICH COULD BE USED TO REFER PATIENTS INTO REMOTE WL PROGRAMS. THE 'WIDELY-APPLICABLE' ALGORITHM WILL USE METRICS COMMON TO ELECTRONIC MEDICAL RECORDS (SEX, BMI, AGE, RACE, ETHNICITY), AND THE 'MORE COMPREHENSIVE' ALGORITHM WILL FURTHER INCLUDE ADDITIONAL BASELINE CHARACTERISTICS (E.G., EDUCATION, HOUSEHOLD INCOME, HEALTH LITERACY, GROUP PREFERENCE, ETC). PARTICIPANTS WILL BE RANDOMIZED AT BASELINE (OUT OF 4 POSSIBLE COMBINATIONS) AND RECEIVE A 12- MONTH, REMOTE-BASED BEHAVIORAL WL PROGRAM. ALL PROGRAMS INCLUDE DAILY SELF-MONITORING OF DIET, EXERCISE, AND WEIGHT AND THE PROVISION OF AUTOMATED FEEDBACK. THOSE RECEIVING THE ONLINE PROGRAM WILL ALSO BE INSTRUCTED TO VIEW VIDEO LESSONS (24 IN TOTAL, 10-15 MIN EACH) WHICH FOCUS ON BEHAVIORAL STRATEGIES FOR CHANGING DIET AND EXERCISE. INDIVIDUALS RANDOMIZED TO THE VIDEOCONFERENCE PROGRAM WILL PARTICIPATE IN 24 GROUP SESSIONS (1 HOUR EACH) DESIGNED TO MIMIC IN-PERSON TREATMENT AND ALLOW FOR PARTICIPANT INTERACTION VIA LARGE AND SMALL GROUP DISCUSSIONS. COACHING CALLS (10-15 MIN EACH) WILL BE MONTHLY AND FOCUS ON INDIVIDUAL BARRIERS, PROBLEM SOLVING, GOAL SETTING, AND FOSTERING SUPPORT AND ACCOUNTABILITY. ASSESSMENTS WILL OCCUR AT BASELINE, 6 (MID-TREATMENT), 12 (POST-TREATMENT), AND 18 MONTHS (FOLLOWING 6 MONTHS OF NO INTERVENTION). SECONDARY AIMS WILL EXAMINE THE EFFECTS OF DELIVERY FORMAT AND COACHING ON INTERVENTION ENGAGEMENT (E.G., FREQUENCY OF SELF-MONITORING), PSYCHOSOCIAL OUTCOMES (E.G., PERCEIVED SUPPORT, SELF-EFFICACY, AND MOTIVATION), 18-MONTH WL, AND THE COST PER KILOGRAM OF WL (TO EXAMINE WHETHER THE ADDITION OF HUMAN SUPPORT IS COST-EFFECTIVE). STUDY FINDINGS HAVE THE POTENTIAL TO INFORM PATIENT REFERRALS AND INSURANCE COVERAGE DECISIONS FOR REMOTE WL TREATMENT.