GPT and obesity due to melanocortin 4 receptor deficiency: For participants with a BMI ≥ 40 kg/m2 (obesity class III) for example, ALT values were 8.03 U/L (95%-CI 5.43–10.62) higher compared to normal weight individuals at the lowest considered quantile of the ALT distribution (q0.10) and 43.54 U/L (95%-CI 33.14–53.93) at the highest (q0.90).