No human studies have evaluated the link between taste and actual food intake, the effect of obesity surgery on the physiological domain of taste, or measured the direct connection between the change of satiety hormones post-obesity surgery and changes in taste recognition, detection or sensitivity, though gut hormones such as PYY and GLP-1 have been implicated in the changes in appetitive reward [55]. Here, PYY is linked to obesity due to melanocortin 4 receptor deficiency.