SLC13A5 and obesity due to melanocortin 4 receptor deficiency: In mammals, deletion of the homolog of Indy (mIndy, Slc13A5), protects mice from high fat diet and aging induced obesity, insulin resistance and nonalcoholic fatty liver disease (NAFLD), at least in part through the activation of the intracellular energy sensor AMP-activated protein kinase A (AMPK) [6].