When someone's under-caloried, they are usually going to be under-carbed too. Frankly, they are going to be low in everything because they are not eating enough!
Not sure what your hair test means you're not utilizing glucose. That sounds like insulin-resistance/hyperglycemia which can be caused by eating too much fat which can block glucose absorption into the cells. Think your pizza with not only a lot of carbs, but a lot of fat also, but since you say you feel better after pizza, it sounds like enough glucose is getting into your cells. You should get more clarification from the testing company what they mean by that.