Although the INSL3 results suggest that there may be a small impact of obesity on Leydig cell functional capacity, multiple regression analysis (Table 3) shows that the effect of BMI becomes negligible for INSL3, although not for T. Similarly, although weight loss can lead to an increase in circulating T23, 32 and consequent health improvement, the results in Figure 4 show that neither substantial weight loss nor weight gain over an average 4.3‐year period in older aged men have any long‐term impact on Leydig cell functional capacity, as represented by INSL3. The gene discussed is INSL3; the disease is obesity due to melanocortin 4 receptor deficiency.