I was looking at an article the other day that was looking at muscle triglycerides in athletes versus type II diabetics. Endurance athletes get fattier muscles, but have high muscle insulin sensitivity/low resistance. They were looking at the saturation of the fat in the muscle, the diabetic's muscle fat was more saturated compared to the athletes. In lipotoxicity studies, the saturated fat especially palmitic seems to be the problem--sort of. When exposed to palmitic acid and sugar, those ceramides are produced and damage occurs. Adding a little bit of oleic acid, monounsaturated fat, or some polyunsaturated fats increases triglyceride synthesis--fat stores increase in the cells, giving a way to dispose of excess free fatty acids (only really excess given the excess elevation of glucose also present), this protects the cells from damage.