An easy way to find the answer to that question is to ignore the advertising and the appealing messages on the front of the box and look at the nutrition label.
First, how much fiber is in a serving of that cereal? Never purchase a cereal with less than 3 grams of fiber per serving. Five or more grams of fiber is even better. Undigestible fiber helps regulate your blood sugar and your feelings of hunger. Dietary fiber is an important aid to preventing many diseases.
Second, check the calories per serving. Healthy types of breakfast cereals serve up less than 120 calories per serving. (While you are at it, look at the serving size. You may need a smaller bowl at breakfast to limit those calories!)
Finally, look at the added sugar. Your serving of cereal should have less than 13 grams of sugar. Don’t even think of sprinkling on more. In addition to weight gain and tooth decay, excess sugar in your diet increases your risk of heart disease and other health issues.