Indeed, a human study has shown that 1) BMI is positively correlated with reward anticipation towards palatable food cues and negatively correlated with appraisal of food consumption, 2) GLP-1 agonist exenatide reverses these effects resulting in lower levels of anticipatory and higher consummatory reward, which leads to lower food intake 3) the activity of different reward system regions varies between obese subjects with type 2 diabetes mellitus (T2DM) and those with normoglycemia (van Bloemendaal et al., 2015). This evidence concerns the gene GLP1R and type 2 diabetes mellitus.