Abstract Body weight is influenced by an interplay of individual and environmental factors. In people with human immunodeficiency virus (HIV), weight is also influenced by disease status with loss accompanying disease progression that is reversed with effective antiretroviral therapy. Weight changes in comparative antiretroviral therapy trials differ by regimen, with greater gains observed with the integrase strand transfer inhibitors dolutegravir and bictegravir, particularly when coadministered with tenofovir alafenamide fumarate, compared with regimens that include agents such as tenofovir disoproxil fumarate that attenuate weight gain. We review weight changes in major randomized trials of preexposure prophylaxis and initial and switch HIV therapy, highlighting the challenges to assessing the role of antiretroviral therapy in weight change. This examination forms the basis for a model that questions assumptions regarding an association between integrase strand transfer inhibitors and tenofovir alafenamide fumarate and excessive weight gain and calls for more careful consideration of these data when making HIV treatment decisions.