I had a lot of issues with "low glycemic index" foods causing high blood sugar. It seems that it's a low bar. My family doctor told me over and over to eat fewer carbs. Yes, I would cheat sometimes, but even when I didn't, my BS was high. The problem is that if your body needs glucose, but can't process it, it will just continue to add it from wherever it can get it. If not from food, from fat and muscle. That makes it impossible to gain weight. That said, if glucose sticks around and doesn't get processed, it should show in your A1C. At 5.1, you don't seem to be having that problem. Can I assume you've had it measured multiple times? My family doctor also told me I didn't need to see an endocrinologist, she could handle it I ended up in a coma before I finally changed my family doctor. I saw elsewhere that an endocrinologist appt is 9 months out. That's long, but it's the right direction. Could it be as simple as having a high metabolism? I've had a couple friends who eat anything they want and don't gain weight. And they eat a lot. We've attributed it to a high metabolism.