Have you checked your blood sugar when that happens? Often high blood sugar can cause you to be sleepy after eating. Tell us something about your diabetes. What do you do to control it? Oatmeal is very carby by the way...I cant eat it, sends my blood glucose into orbitI dread eating because every time I eat, not necessarily over-eat, I get the "sleepies" and have to take a nap. I've tried eating leafy-green veges only, oatmeal, it doesn't matter what I eat, I get the sleepies.