Like "You are experiencing a rush of carbs in your system and if you check your BG after a meal you will probably be surprised how high your BG is. Your body can't produce the insulin to combat the large and sudden volume of carbs you have consume. Are you taking a multi-vitamin? And yes, I feel very tired after ingesting a large quantity of carbs. Start counting your carbs at each meal. This will give you an accurate record of your carb intake and allow you to adjust intake to a level your body can best handle. LIVE WELL"