Answer : The quick answer would seem to lie in the USDA nutrient database, where regular, quick and instant oatmeal all share a single listing. Since they all have the same amount of fiber-4 grams per 1 cup of cooked oatmeal-its logical to assume all varieties have the same amount of beta-glucan, the special kind of fiber that gives oats (as well as barley) their cholesterol claim to fame. But we got curious: What do they do to oats, anyway, to make instant or quick-cooking oatmeal-and could that process affect the fiber in some way?
Cynthia Harriman, director of food and nutrition strategies for The Whole Grains Council www.WholeGrainsCouncil.org, looked deeper into this question for us. Her sources confirmed that equal amounts of any kind of oats-steel-cut, regular rolled, quick or instant-all have equal amounts of soluble fiber and therefore of beta-glucan. If you compare a serving of regular or steel-cut oats, usually considered a half-cup dry, to a serving of instant oatmeal in a packet, however, the instant will have less fiber-but only because a packet holds less than a half-cup.
So whats the difference between the different types of oatmeal? Plain oatmeal groats-whole kernels-take a very long time to cook. Steel-cut oats are groats cut into two or three chunks; they cook a little quicker because the pieces are smaller and the water can penetrate more easily. Rolled oats have been steamed and then rolled flat and dried. Because theyve been steamed (precooked a bit) and rolled (extending their surface area, to make it easier for the water to penetrate), they cook even more quickly. Rolled oats come in three forms: regular oats-whole groats, rolled; quick oats-oats cut in pieces and then rolled thinner; instant oats-cut even smaller and rolled even thinner to cook the quickest of all. Healthwise, the bottom line is that nothing is taken out in processing, so all these oatmeal varieties are whole grains.