LEP and obesity due to melanocortin 4 receptor deficiency: The observed reduction in SCD-18 activity index among AN is consistent with previous findings that lower SCD-18 index (as well as SCD-16 index) correlated with lower body fat and BMI in older individuals [73], and that downregulation of SCD-1 (the collective name referring to both SCD-16 and SCD-18) hindered adiposity and obesity in leptin-deficient obese mice [74].