I only use old fashioned oatmeal, the kind you cook for 10-15 minutes, and it is not only one of the best nutient dense low gi carbohydrates, but cooked oatmeal ingested on a regular basis helps maintain an acidophilus friendly coating in the intestinal tract, thus aiding in total digestive tract health.
I don't like uncooked oats or instant oats for several reasons:
1. Oatmeal contains phytic acid. Phytic acid will bind with calcium, magnesium, phosphorous, iron, and zinc in the intestine. Cooking not only removes a lot of the phytic acid, but makes the oats easier to fully digest.
2. Modern oatmeal goes stale. The time between when the oats are ground and when you eat them is quite long. They are not vacuum packed or nitrogen sealed (like ground flax seeds often are). The oats then oxidize, causing a loss in B vitamins and vitamin E. This is even worse the more finely ground the oats are. While instant oats might contain less bran and therefore less phytic acid, it will oxidize faster as more and more of the whole grain is taken out.