Motivating systems-oriented research on environmental and policy changes for obesity prevention.

BACKGROUND: Research on the types of interventions needed for population-level prevention of childhood obesity in complex societal systems can benefit from greater use of systems-science concepts and tools. OBJECTIVES: We report outcomes of a funding programme promoting incorporation of systems-science approaches into studies of imminent policy or environmental changes potentially impacting childhood obesity. METHODS: Seven funding cycles over 3 years yielded 172 initial submissions from 29 US states and 25 other countries were analyzed. RESULTS: Submissions focused primarily on aspects of school or child-care settings, parks and recreational settings, or access to healthy food; about half reflected attention to systems perspectives. CONCLUSIONS: Analysis of initial submissions as well as the 15 funded projects showed some success in motivating use of systems concepts and tools but suggested the need for a more focused effort to educate and prepare the childhood obesity prevention research community for this potentially crucial type of research.

Effect of highly active antiretroviral therapy on fat, lean, and bone mass in HIV-seropositive men and women.

BACKGROUND: Alterations in body composition have been reported in HIV-positive adults receiving highly active antiretroviral therapy (HAART), but the magnitude and potential determinants of these changes are unclear. OBJECTIVE: We compared total and regional body composition, as measured by dual-energy X-ray absorptiometry, in 203 HIV-positive men and 62 HIV-positive women according to HAART. DESIGN: This was a cross-sectional analysis of a cohort study of nutrition and HIV infection. RESULTS: After adjustment for age, weight, race, and exercise habits, total weight and fat mass did not differ significantly in men or women by HAART. Trunk fat was greater in men (1.0 kg; P < 0.001) and women (1.4 kg; P = 0.005) and leg fat was lower in men (-1.0 kg; P < 0.001) and women (-1.5 kg, P = 0.005) receiving HAART than in those not. This corresponded to a greater percentage of total fat mass located in the trunk (men: 7.5%, P < 0.001; women: 5.1%, P = 0.02). Lean mass was also greater with longer duration of HAART in men (P < 0.002). In men receiving HAART, total and regional bone mineral content were less than in the men not receiving HAART (P < 0.001). These effects increased with longer duration of HAART. Protease inhibitors were associated with the largest differences in regional fat. CONCLUSIONS: HAART is associated with redistribution of fat mass from the legs to the trunk, despite no significant differences in total fat mass or weight. In men, HAART is also associated with a reduction in bone mineral content, suggesting that HAART increases the risk of central obesity and osteoporosis.