Does hyperglycemia cause you to lose your appetite?

Yes and no: Very high sugar levels will suppress appetite somewhat. However, as your sugar levels fall from that elevated level, your appetite may be inappropriately triggered. That is the reasoning behind the use of metformin in weight control- it moderates the blood sugar spikes and minimizes cravings caused by high glycemic foods.

Not typically: Excessive hunger can actually be a symptom of diabetes out of control.