INS and obesity due to melanocortin 4 receptor deficiency: While high levels of intracellular lipid content is often associated with metabolic pathologies such as type 2 diabetes mellitus and obesity (Bonen et al., 2000; Jacob et al., 1999; Pan et al., 1997), the accumulation of TG in athletes and endurance trainers has been shown to improve insulin sensitivity (Goodpaster et al., 2001; Jacob et al., 1999; Schenk & Horowitz, 2007), a phenomenon known as the athlete's paradox.