Fiber is simply undigestible carbohydrates, and they are found in all kinds of plants, not just grains.
Plenty of fruits and vegetables, like apples, pears, bananas, peppers, spinach, & pumpkin, are high in fiber. And, there is no reason to presume that the fiber in grain is in any way superior to the fiber in fruit and vegetables.
An apple has 3g of fiber.
A cup of multi-grain cheerios has 3g of fiber.
Which is really the better choice?
