I've come to the same conclusions with the exception of caffeine, alcohol, and meat. The first two in moderation and the last item not at all due to digestive issues. Vegetarian diets tend to gravitate towards a high carb diet. Restricting the amount of carbs I eat down to more moderate level has resulted in me feeling much improved. However, on long ride days I tend to eat more complex carbs. I am unsure if I will use simple carbs again. They do seem helpful if consumed with a complex carb when you are in the hole energy wise but that is just about it. The blood sugar spikes while riding are rather annoying.