Tagatose (an epimer of fructose) is a rare sugar that has antioxidant and prebiotic effects, reduced glycaemic and insulinemic responses, and the potential to improve lipid profile, to induce a lower expression of proinflammatory cytokines, catalase and superoxide dismutase, to decrease lesion area and macrophage infiltration, and to stimulate GLP1 release, therefore constituting an alternative candidate for the treatment of diabetes mellitus and obesity (Guerrero-Wyss et al. 2018; Nagata et al. 2018). Here, GCG is linked to obesity due to melanocortin 4 receptor deficiency.