When comparing BMI SDS with a cutoff value of 5.57 for obesity in IGHD, if the peak-stimulated GH level was below 5.57, the mean BMI SDS was −0.13 SDS, significantly higher than the mean BMI of −0.37 SDS, when peak-stimulated GH was 5.57 and above (P = 0.03) (data not shown). This evidence concerns the gene GH1 and obesity due to melanocortin 4 receptor deficiency.