d-lactate dehydrogenase (LDHD) is a mitochondrial protein that catalyses specifically the reduction of d-lactate to pyruvate with concomitant oxidation of NAD+ to NADH [47]; it may play a role in regulating apoptosis, cell proliferation and cell differentiation, serving as a general indicator of acute and chronic diseases [48]; however, there is not much evidence available associating altered abundance of this protein in individuals with obesity. This evidence concerns the gene LDHD and obesity due to melanocortin 4 receptor deficiency.