To look very closely to the nutrition sources
proteins,
type of fats (unsaturated fat, monounsaturated fat; polyunsaturated fat, saturated fat, transafats)
carbohyfrates
and which additives, food preservative and if you're allergic to something, just check twice.....
cereal for better health shouldn't contain much of these. You van make your own cereals by mixing different cereals, adding fruits, honey, and milk (cow milk or vegetal milk) or yogurt....
Anyway, never buy cereals because the brand is famous.....it's industrial and some brand, quite unknown, are much more healthier.....more natural...
hope I helped