SUMMARY Pacific Islanders in the US are disproportionately affected by diabetes, obesity, and hypertension. Among US Pacific Islanders, those most at risk are resident in the US-affiliated Pacific Island territories, which are geographically isolated, medically underserved, health professional shortage areas. Despite obesity often being established in childhood, adolescence is a critical time for intervention to prevent associated chronic diseases. In American Samoa, this age group has been completely overlooked in existing efforts to mitigate disease risk. There is a need to intervene on adolescent's individual behaviors, but health-related decisions are not made in vacuum – family, peers, and the wider surrounding environment are important influences. Equally, adolescents play a critical role in food preparation in the Samoan familial structure and are responsible for cooking daily meals for immediate and extended family from early adolescence, thereby shaping familial risk. To date, there has been limited consideration of specific Samoan cultural and social influences on adolescent risk behaviors. The important impacts AS adolescents may have on familial and peer habits have also been underrecognized. Therefore, the central premise of this thesis is to understand the distribution of obesity, diabetes, and hypertension, and factors associated with these conditions, in the adolescent population in American Samoa. With this proposal we will: (1) use qualitative methods to identify factors influencing healthful nutrition among American Samoan adolescents; (2) employ a school-based survey to identify factors associated with obesity, diabetes, and hypertension in adolescents in American Samoa; and (3) use social network analysis to examine the patterning of obesity, diabetes, and hypertension among friendship networks in American Samoa. Findings from this work are expected to enhance our understanding of the range of behavioral and social influences on chronic disease risk in this setting and to concretely inform future intervention strategies. Importantly, the findings are likely to translate to Pacific Islander adolescents in other settings in the US and US-affiliated Pacific Islands. Through this work the applicant will develop skills in qualitive methods, advanced epidemiologic study design and management of epidemiological surveys, and social network analysis. This training is central to the applicant's long-term goal of become a Pacific-focused noncommunicable disease epidemiologist integrating advanced epidemiologic methods with locally relevant interventions to support health promotion in Pacific Island communities.