Toss the banana, kiwifruit, oats, cereal, shredded wheat, whole grain wheat flakes, ground flaxseed, raisins, and walnuts into a bowl.
After cutting the grapefruit in half, use a small, sharp knife to remove the segments. Add the segments to the top of the bowl and squeeze in the juice. Top the bowl with milk substitute.
To lower cholesterol levels even more, use 1/2 cup oats and omit 1/4 cup of either cereal.