I can eat 40g of carbs for breakfast, sorghum cereal with whey portein mixed in. 3 eggs scrambled, a small amount of chicken, nuts, coffee (Black), glass of water with a tblsp of apple cider vinegar, my usual vitamins etc and have a reading around 7 at the 2hr mark and 5 at 3 hrs.
Breakfast time is the best time for me to eat carbs, dinner time is the worst. 50 - 60g of carbs a day seems to work for me, but as you can see... it's a timing thing. Individual variability.