G6PD and obesity due to melanocortin 4 receptor deficiency: For example, G6PD activity is increased by carbohydrate-rich diet and insulin, and the suppression of G6PD relieves high fat diet-induced weight gain as well as the related metabolic reprogramming in liver and visceral fat, suggesting that G6PD acts as a functional regulator of high fat diet -induced obesity and fatty liver 69.