The World Health Organization, UNAIDS, and the World Food Program have recognized that food insecurity is a major threat to the effectiveness of emerging antiretroviral treatment (ART) programs in sub- Saharan Africa as a result of its adverse impact on ART adherence and HIV disease transmission and progression. Yet there has been very little empirical research on these issues to guide policy decisions. Working under the mentorship of internationally recognized scientists, I propose 3 specific research aims: (1) To determine the impact of food insecurity on ART adherence among HIV-infected individuals in the Uganda Antiretroviral Treatment Outcomes (UARTO) cohort in Mbarara, Uganda; (2) To determine the impact of food insecurity on HIV treatment outcomes in the UARTO cohort; and (3) To determine the impact of food insecurity on high-risk sexual behaviors in the UARTO cohort and how gender modifies these relationships. I will leverage the resources of the UARTO cohort, an ongoing prospective observational cohort study of 500 HIV-infected individuals on ART treatment in Mbarara, Uganda and follow all patients in the cohort longitudinally every 3 months for a 2-year period. The pre-existing infrastructure of the UARTO cohort, including the operational protocols and strong community relationships, will help ensure that the current proposal is both cost-effective and feasible. This study is innovative in that it will provide the first quantitative and the first longitudinal assessment of the effects of food insecurity on ARV adherence, HIV treatment outcomes, and HIV risk behaviors in ART-treated patients in sub-Saharan Africa. By contributing to a dialogue between those involved in international food policy and those involved in ART roll-out in sub- Saharan Africa, this research may help both groups utilize their limited resources more effectively. This research is integrally linked to my training program, which includes the design, implementation, and analysis of longitudinal studies; content expertise in nutritional epidemiology and international food policy; and the design and implementation of intervention trials. This proposal will provide the preliminary data and training for the development of an intervention study of the role of targeted food assistance on HIV health outcomes and sexual-risk reduction among individuals enrolled in ART programs in sub-Saharan Africa, which will be proposed as an R01 at the end of the study period.