CD4 and obesity due to melanocortin 4 receptor deficiency: However, a recent single-cohort study of HIV-infected adults in the southeast of the USA (a region with a high prevalence of obesity) found that a 12-month CD4+ lymphocyte gain after ART initiation was greatest among those with a pretreatment BMI of 25 to 30 kg/m2, and it diminished above and below this range [26].