What can too much sugar cause except for high glucise levels?

talk to your doctor about it...

My fasting glucose levels got a little high, but then they went down. The doctor said the best measure is the A1c test.

My A1c showed in the spring that although my fasting glucose levels were well under 100, my A1c showed prediabetes, (57). Then in the fall I got tested again, I had lost weight and started taking 15g of powdered glycine every day in place of sugar, and my A1c went down to 50.

Are you sure about those numbers? They don't relate to any A1c I've ever seen. Did you mean 5.7 and 5.0? Without the decimal, you would draw flies like a caramel covered apple.

Oops, yes the A1c was 5.7 in the spring, 5.0 in the fall. The fasting glucose and random glucose tests are around or just under 100, the A1c was single digits.