THIS PROPOSAL IS A MULTI-FUNCTIONAL INTEGRATED RESEARCH, EDUCATION AND EXTENSION PROJECT TO EVALUATE THE LONG TERM IMPACTS OF THE STARTING EARLY PROGRAM (STEP) AND TO DEVELOP AND EVALUATE A TWO-FOLD EXPANSION OF THIS NOVEL APPROACH TO PREVENTING EARLY CHILD OBESITY. THIS PROPOSAL FULLY INTEGRATES RESEARCH TO DETERMINE THE EFFICACY OF THE STEP INTERVENTION AND KEY FACTORS CAUSING EARLY CHILDHOOD OBESITY, EDUCATION OF PREGNANT WOMEN AND MOTHERS AS WELL AS DIETETIC/NUTRITION AND PRIMARY HEALTH CARE PROVIDERS AND EXTENSION INTO (1) THE FAMILIES, FOOD AND FITNESS EXTENSION COMMUNITY OF PRACTICE; (2) PRIMARY HEALTH CARE SETTING; AND (3) SUPPLEMENTAL NUTRITION PROGRAMS FOR WOMEN, INFANTS AND CHILDREN (WIC). EXTENSION INTO THESE AREAS WILL ENSURE CONTENT DISSEMINATION AND SUSTAINABILITY OF THE STEP INTERVENTION.STEP BRINGS TOGETHER 3 KEY INNOVATIONS CRITICAL TO EARLY CHILD OBESITY PREVENTION. FIRST, STEP FACILITATES EFFECTIVE PRIMARY PREVENTION BY WORKING WITH PREGNANT WOMEN AND MOTHERS BEFORE THE ONSET OF CHILD OBESITY. SECOND, STEP IS SPECIFICALLY DESIGNED TO EDUCATE LOW SOCIOECONOMIC STATUS (SES), LOW HEALTH LITERACY GROUPS AT THE GREATEST RISK OF HEALTH DISPARITIES, USING LOW COST, EVIDENCE-BASED STRATEGIES TO PROMOTE HEALTHY EATING AND PHYSICAL ACTIVITY PATTERNS FOR OBESITY PREVENTION. THIRD, STEP CAN BE DELIVERED IN BOTH PRENATAL AND PEDIATRIC PRIMARY CARE, PROVIDING A UNIQUE OPPORTUNITY FOR EXTENSION WITH WIDE-SPREAD FREQUENT ACCESS TO AT-RISK POPULATIONS, AS WELL AS THE ABILITY TO TRAIN DIETETIC/NUTRITION AND PRIMARY HEALTH CARE PROVIDERS IN THESE STRATEGIES. THE LOCATION OF STEP IN A LARGE PRIMARY HEALTH CARE SYSTEM WITH CO-LOCATED WIC CENTERS PROVIDES A FRAMEWORK FOR POPULATION SCALABILITY.DURING THE LAST 5 YEARS, WITH FUNDING FROM THE USDA (AFRI # 2011-68001-30207), WE DEVELOPED, IMPLEMENTED AND STUDIED THE ORIGINAL STEP PROGRAM (STEP:P-3), WHICH BEGINS IN THE 3RD TRIMESTER OF PREGNANCY AND CONTINUES THROUGH CHILD AGE 3 YEARS OLD. STEP:P-3 IS THE ONLY LARGE SCALE RANDOMIZED CONTROLLED TRIAL (STEP-RCT) TO EVALUATE EARLY CHILD OBESITY PREVENTION FOR PREGNANT WOMEN AND MOTHERS IN PRENATAL AND PEDIATRIC PRIMARY CARE. THE STEP:P-3 INTERVENTION INCLUDES INDIVIDUAL NUTRITION COUNSELING IN THE PRENATAL AND PERI-PARTUM PERIODS AND NUTRITION/PARENTING SUPPORT GROUPS COORDINATED WITH PRIMARY CARE VISITS FROM PREGNANCY THROUGH CHILD AGE 3 YEARS OLD. THE INDIVIDUAL AND GROUP COUNSELING MODEL UTILIZES A SOCIAL LEARNING FRAMEWORK AND EMBEDDED SOCIAL SUPPORT TO PROMOTE ACTIVE LEARNING AND LONG TERM BEHAVIOR CHANGE. TO DATE, STEP-RCT HAS COMPLETED ITS TARGET ENROLLMENT OF 567 PREGNANT WOMEN. FOLLOW-UP ASSESSMENTS OF THE MOTHER INFANT DYADS AT INFANT AGE 3, 10, 19 AND 27 MONTHS OLD HAVE BEEN COMPLETED BY 456, 412, AND 386 DYADS RESPECTIVELY, AND 112 DYADS HAVE COMPLETED THE PROGRAM AND FINAL ASSESSMENTS AT CHILD AGE 36 MONTHS.OUTCOMES FROM STEP HAVE YIELDED SIGNIFICANT IMPACTS FOR RESEARCH, EDUCATION AND EXTENSION. RESEARCH FINDINGS FROM THE STEP-RCT INCLUDE IMPACTS OF THE STEP:P-3 INTERVENTION ON OBESITY RELATED FEEDING AND LIFESTYLE BEHAVIORS. INTERVENTION MOTHER-INFANT PAIRS HAVE HIGHER RATES OF EXCLUSIVE BREASTFEEDING, DAILY INFANT TUMMY TIME, LOWER RATES OF EARLY INTRODUCTION OF COMPLEMENTARY LIQUIDS AND SOLIDS AND DECREASED JUICE CONSUMPTION AND TV VIEWING DURING FEEDING THAN CONTROLS RECEIVING STANDARD PRIMARY CARE. THEY ALSO HAVE IMPROVED FEEDING STYLES. IN PRELIMINARY ANALYSES, STEP:P-3 INTERVENTION INFANTS HAVE LOWER MEAN WEIGHT FOR LENGTH Z-SCORES THAN CONTROLS AT AGE 18 MONTHS. EDUCATION OUTCOMES INCLUDE IMPROVED NUTRITION KNOWLEDGE IN INTERVENTION MOTHERS, A TRAINING PROGRAM FOR DIETETIC INTERNS IN OBESITY PREVENTION AND COMMUNITY NUTRITION, TRAINING FOR NUTRITION PHD'S AND A POST-DOCTORAL TRAINING FELLOWSHIP PROGRAM IN PRIMARY CARE-BASED EARLY CHILD OBESITY PREVENTION FOR PEDIATRICIANS. EXTENSION OUTCOMES INCLUDE 1) THE SUCCESSFUL ENGAGEMENT OF 3 KEY STAKEHOLDERS IN MATERNAL-CHILD HEALTH FOR LOW-INCOME FAMILIES: A) BELLEVUE HOSPITAL CENTER, WHICH IS PART OF THE NEW YORK CITY HEALTH AND HOSPITALS (NYCHH), ONE OF THE NATION'S LARGEST PROVIDERS OF PRIMARY HEALTH CARE FOR LOW-INCOME FAMILIES; AND B) THE BELLEVUE HOSPITAL WIC CENTER; AND 2) THE COMPLETION OF A COMPREHENSIVE, DETAILED INTERVENTION MANUAL FOR WIDESPREAD DISSEMINATION OF THE PROGRAM.THIS RE-SUBMISSION TO THE 2016 RFA DESCRIBES A TWO-FOLD EXPANSION OF THE STEP PROGRAM WHICH INCLUDES: 1) EVALUATION OF THE LONG-TERM IMPACTS OF STEP:P-3 BY FOLLOWING THE COHORT THROUGH CHILD AGE 3 TO 5 YEARS OLD; 2) DEVELOPMENT AND EVALUATION OF AN EXPANDED INTERVENTION FOR 3 TO 5 YEAR OLDS CALLED STARTING EARLY PRESCHOOL (STEP:3-5); AND 3) DEVELOPMENT AND EVALUATION OF AN EXPANDED PRENATAL INTERVENTION CALLED STARTING EARLY EXPANDED PRENATAL (STEP:EXP-3) WHICH WILL BEGIN EARLIER IN PREGNANCY. EXPANSION OF THE STEP INTERVENTION WILL BE LINKED TO EXPANSION OF OUR ON-GOING EDUCATION OF PARENTS, DIETETIC/NUTRITION AND MEDICAL PROVIDERS, AND EXTENSION INTO THE FAMILIES, FOOD AND FITNESS EXTENSION COMMUNITY OF PRACTICE, PRIMARY CARE, AND WIC. THIS PROPOSAL WILL INTEGRATE RESEARCH, EDUCATION AND EXTENSION TO DECREASE THE PREVALENCE OF EARLY CHILD OBESITY, EDUCATE PREGNANT WOMEN, MOTHERS, YOUNG CHILDREN AND PRIMARY CARE PROVIDERS IN EFFECTIVE OBESITY PREVENTION STRATEGIES, AND EXTEND PROGRAM IMPACTS ON A LARGE SCALE FOR COMMUNITIES AT HIGH RISK OF DISPARITIES IN CHILD OBESITY. TO OUR KNOWLEDGE, THIS IS THE ONLY EXISTING LARGE COHORT OF LOW-INCOME HISPANIC MOTHER-INFANT PAIRS FOLLOWED LONGITUDINALLY SINCE PREGNANCY AND REPRESENTS A UNIQUE AND TIME-SENSITIVE OPPORTUNITY TO FILL CRITICAL KNOWLEDGE GAPS IN THIS UNDERSTUDIED GROUP, BUILD EDUCATIONAL CAPACITY AND SUSTAIN PROGRAM IMPACTS.