Insulin resistance is sort of problematic. Fung has used the idea that exposure to excess insulin causes insulin resistance. It's certainly a stimulus that we had better adapt to. If our fasting insulin doubles, and has the same effect that it would have had before it doubled, we'd be hypoglycemic.

I think insulin resistance is fine, but to be technically correct we have to be more specific. If you get fat, are you insulin sensitive? Certainly you were sensitive to the fattening effects of insulin. But at that point, a given unit of insulin will not be as fattening as it would have been before you became fat. At that point, you'll get less of a response to a unit of insulin, just about anywhere in the body. Go ahead and call it hyperinsulinemia if you will, but like it or not, it's still insulin resistance. And this insulin resistance can lead to accumulation of fat in and around the vital organs, due to compromised ability of the overloaded fat cells to regulate fatty acid levels in the blood.

But you're not getting fatter, if you are, because you're insulin resistant in your fat cells. You might be getting fatter because you're insulin resistant centrally--or at least not responding to insulin appropriately, maybe due to dysfunction of the pattern of insulin secretion--in your pancreas and liver, which could lead to further fattening. There you're getting fatter to the extent that your fat tissue is sensitive to the levels of insulin, but the hyperinsulinemia is itself a consequence of the central insulin resistance.