GCG and obesity due to melanocortin 4 receptor deficiency: Exposure to hypoxic conditions simulating an altitude of 2,500–3,500 m for approximately 10 days decreased body weight and percent body fat via glucagon-like peptide-1 inhibition, improved insulin sensitivity, decreased dietary intake and serum leptin level elevation, increased basal metabolic rate, and decreased diastolic blood pressure, thereby effectively preventing and treating obesity and obesity-related diseases (57, 67).