INS and obesity due to melanocortin 4 receptor deficiency: Interestingly, as previously discussed, longer rather than shorter chain phospholipids have been negatively associated with obesity and diabetes, and the hypoglycaemic effect of insulin has been shown to improve when phospholipids of reducing carbon numbers from C18 to C10 are involved (Giesbertz et al. 2015; Li and Mitra 1996).