carbohydrate dysmetabolism

Me: 25, 169lb, normal fasting sugars (~80), elevated postprandial sugars, I often see them go up to 160-170 after a high-carb (~100g) meal. I test before and after meals. Latest A1C was 5.5%. All bloodwork/B12/vitamins are normal. Not on any medications, not formally diagnosed with prediabetes...

I briefly discussed my undiagnosed pathology about six weeks ago in response to a poster's question. I am restating the problem in its own thread in great depth for wider review. I am a 70 year old retired scientist. I'd appreciate any input this community may offer. A Lay Opinion of the...