LEP and obesity due to melanocortin 4 receptor deficiency: - Leptin concentration declined by 39.4%.- Decrement was associated with an increase in fasting hunger (r=0.42, P<0.01), desire to eat (r=0.39, P<0.05) and total appetite (r=0.38, P<0.05).- Higher absolute (not relative) reduction in individuals with obesity (-4.1 ng/ml) or who were overweight (-1.5 ng/ml) than in participants with BMI <25 kg.m2 (2.2 ng/ml).