The principle factors driving individuals toward either the sarcopenic-obese or healthy-obese phenotype are currently unknown but might include differences in physical activity and caloric intake as these are known regulators and associating factors to many of the potential causes of sarcopenia and obesity (i.e. reduced lean mass, elevated oxidative stress and inflammation, impaired muscle regeneration, anabolic and insulin resistance, nutrient ‘overload’ and metabolic dysfunction etc.)(66, 80). This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.