Diet comprised of cereal?

I was thinking of eating different types of low fat organic cereal with organic skim milk 3 times a day. I was going to mix in bananas to some, and a powdered protein supplement at least once or twice a day. I would of course be taking a multi-vitamin and munching on veggies between meals. Has anyone ever tried a diet similar to this? I'm trying to control weight and tone up, thanx!