Our main findings were that a) the circulating levels of active ghrelin were equally reduced in all groups between the fasting vs. 60 min post-meal time-points; b) active GLP-1, insulin, and plasma glucose levels increased in all groups between the fasting vs. 30 and 60 min post-meal time-points; c) higher increases in plasma glucose were detected in those individuals with obesity and dysglicemia vs. controls and normoglycemic individuals with obesity at 30 and 60 min post-meal. The gene discussed is GCG; the disease is obesity due to melanocortin 4 receptor deficiency.