In considering weight gain in treated HIV infection, it is important to distinguish the “return to health” weight gain that can occur in the setting of cART initiation from the trajectory of undesirable and unhealthy weight gain that reflects modern western living and transition towards obesity. The ‘return to health’ describes the weight gain that follows cART initiation which ameliorates the debilitating catabolic infection that has depleted body fat and protein stores that characterise untreated HIV infection. This phenomenom and the studies documenting it are reviewed in detail elsewhere (51). With international practice and guidelines recommending cART initiatiion after HIV infection detection, fewer people with untreated HIV infection in Australia experience the cachectic and wasted nutritional state that characterised earliest clinical experience (52). Suppression of HIV replication by cART and normalisation of the associated increases in systemic inflammation restore resting energy expenditure (52), representing effective viral suppression and CD4+ T cell recovery (53).
Separate to the weight gain which characterises suppression of HIV infection and the “return to health”, is the weight gain that reflects the individual living with HIV infection caught in the modern obesogenic environment. Overweight and obesity currently affects 50-60% of Australian adults. Recent studies find that people with HIV infection have overweight and obesity rates similar to the uninfected population (52, 54-58). US data from 2000 onwards show high rates of overweight and obesity in 40-63% of people with HIV infection, both pre-cART and on cART, paralleling US obesity statistics in the general population (56-58). Recent US data also show that 44-54% of people initiating cART are either overweight or obese, prompting the query “where did all the wasting go?” (20, 23).
Studies on weight gain after cART-initiation and transition into harmful categories of excess weight show that 20% of people with healthy weight at baseline become overweight or obese by 24 months following cART-initiation (52). These studies highlight the elevated and rising obesity rates in people with HIV infection from well-nourished nations. Health care practitioners are encouraged to address overweight and obesity as part of standard cardiometabolic care for people with HIV infection, as they would for any individual with increased cardiometabolic risk, with standard practice of dietary intervention (focusing on energy restricting diets with psychological support for chrnoic behaviour change), pharmacotherapy, or bariatric surgery. Referral to a specialist obesity service is recommended where initial dietary interventions do not succeed.