This is a retrospective longitudinal study that evaluates the prevalence and incidence of overweight/obesity within an HIV-infected population before and after 12 and 24 months of a stable antiretroviral therapy (ART). The study group will be compared to the weight of a healthy, matched population that is not infected with HIV. The primary hypothesis states that the proportion of HIV-infected persons newly classified as overweight/obese will increase by ≥20% after 12 months of initial ART, and this incidence will be greater than that of a matched HIV-uninfected control population. The effect of immune function variables, such as CD4, HIV viral load, and ART regimen on weight will be analyzed. In addition, the study will analyze the effect of weight and immune function markers on the inflammatory markers, high sensitivity C-reactive protein (hsCRP) and D-dimer. An HIV samples repository will be used for specimens to be assayed for hsCRP and D-dimer.