The hormone leptin is largely responsible for the accuracy of insulin signaling and whether you become insulin resistant or not. Leptin, a relatively recently discovered hormone produced by fat, tells your body and brain how much energy it has, whether it needs more (saying "be hungry"), whether it should get rid of some (and stop being hungry) and importantly what to do with the energy it has (reproduce, upregulate cellular repair, or not). In fact, the two most important organs that may determine whether you become (type 2, insulin resistant) diabetic or not are your liver and your brain, and it is their ability to listen to leptin that will determine this. When your blood sugar becomes elevated it is a signal for insulin to be released to direct the extra energy into storage. A small amount is stored as a starch called glycogen in your body, but the majority is stored as your main energy supply -- fat. Thus, in this regard insulin's major role is not to low