Hi, a few words of explanation on the graphic above. It's taken from Bilous and Donnelly "Handbook of Diabetes" and is figure 5.20 in the 4th edition. You'll see the number of places that "ins" appears in the graphic. That's where insulin has a job to do.
(NIMGU btw is non-insulin mediated glucose uptake, cats is catecholamines, cort is cortisol, glcg is glucagon)
Yes, insulin does play a role in the storage of glucose as bodyfat and use of bodyfat for energy. It equally plays a role in the storage and use of glucose in and by skeletal muscle and the creation of glucose and glycogen by the liver. In other words, it's a necessary item for remaining alive.
[edited for spelling error]