Mass-produced stuff is totally unpredictable. Your basic corn flakes, bran flakes, cheerios, and rice krispies are typically fine. Life is fine. Kiddie cereals, unfortunately, are nearly all hydrogenated. Granola needs to be watched carefully.
Instant oats are an excellent replacement, but watch out for pre-fab flavored oatmeals.
Granola bars . Your basic rolled oats and honey is usually safe. Anything chewy or coated is going to be a hydro bomb. Kiddie granola bars are the worst offenders. Johnson's Old Fashioned, sold in many discount chains, is straight peanuts and salt, which is all you need.