(P24-045-24) Modeling the Contribution of Mobile Food Vendors to Food Choices and Body Weight Dynamics Among People Living With HIV in Dar Es Salaam, Tanzania

Objectives: As the life expectancy of people living with HIV (PLHIV) has increased, chronic cardiometabolic co-morbidities have become a greater burden for this population. This population may experience both generic risk factors such as a poorer overall diet, and HIV-specific risk factors such as alterations in fat deposition and storage, and greater difficulty building and maintaining muscle mass. There is a need to better understand how PLHIV navigate their food environment, and how their food choices and dietary intake impact downstream health outcomes.

Methods: We developed an individual-based, spatially explicit agent-based model to model relationship between the informal and formal food environment on the energy intake, and subsequent body composition, of PLHIV in Dar Es Salaam, Tanzania. Data from the DECIDE study, which previously identified characteristics of the food environment associated with reported vegetable consumption and total energy intake among N=239 PLHIV, was used to estimate parameters related to food purchases (food items and vendor types) and energy intake. A validated model of body composition dynamics, where the partitioning of energy intake between fat mass and fat free mass was estimated from a review of longitudinal cohort studies of body composition was then used to relate changes in food choices to body weight dynamics over a decade. This model was used to simulate the impact of an intervention targeted towards changing the food-environment by increasing or decreasing the number and kind of different food vendors.

Results: Empirical data suggested that informal, mobile food vendors were the preferred source for fruits and vegetables, and that purchases from these vendors depended more on geographic proximity than was the case for purchases from larger, formal vendors. When translated into the model, this meant that, when informal produce vendors were reduced or replaced in the food environment, PLHIV gained less total weight, but more fat mass (and less fat free mass), than family members without HIV.

Conclusions: Interventions that support informal, mobile vegetable vendors may be especially important for supporting the diets of the general population. PLHIV benefits from such efforts.

Funding Sources: National Institutes of Health (K01AI145080 to GOL)