AKT1 and obesity due to melanocortin 4 receptor deficiency: Given the biological role of the PI3K/Akt pathways in cellular growth and hypertrophy, we suspect, much like the results of Mercken et al. [37], the diet would have the effect of “normalizing” PI3K/Akt signaling in persons with obesity, which would mean that the differences we found between groups would have been larger if we analyzed samples from pre-diet patients with obesity.