If you have a busy morning routine, then the instant oatmeal is going to look most appealing to you. After all, you can just zap it in the microwave, and breakfast would be served. But is the instant oatmeal as healthy as the other two types? Instant oatmeal is a nutritious food, and it does contain fiber. However, if you are trying to eat the type of oatmeal with the greatest concentration of fiber, then instant oatmeal is not the oatmeal for you. Nonetheless, instant oatmeal is still a good choice for those of us who need to rush to get out the door. Just make sure it is the plain type of instant oatmeal, and not the one packed with sugar.
Want the oatmeal with the most fiber? Go with the steel cut oats. Just be willing to spend about half an hour cooking them.
Rolled oats are more processed than the steel cut ones. That is why they take less time to cook. However, they still contain more fiber than the instant ones.