I had the same problem until I switched to whole carbs only. I have noticed that my blood sugar was spiking when I was eating refined or highly processed foods but not when I changed to whole foods.Basicaly only carbs. I'm sceptical as I experimented with all of that and my BG reacted to this food as to any other carbs.
Please note that when I said that I was bulking up my salad with beans, etc., the carb was a small part of the meal, not the main.