Cold cereals come in flakes, puffs, Os, biscuits, and many other forms. They vary widely in nutritional value, from sugar-coated, brightly colored puffs to 100-percent wheat bran. Whole- and multigrain cereals, unsweetened or lightly sweetened with barley malt syrup or molasses, are generally the most nutritious. Read labels carefully: even so-called “healthy” granola may have 400 calories and more than 16 grams of fat in one serving.