Choosing a healthy breakfast cereal is important to assure that we take in the necessary nutrients that we need.
The most important and simple thing to do is of course to look at the actual list of ingredients. If the first and second ingredient is whole grain, you are safe that you have bought the right breakfast cereal. If the word "whole" does not appear, you can assume that the grains are not whole but refined.
For those who are on a diet, it is still important to have a balanced diet and having cereals only will not get you down to the right path. Overeating of cereals can still cause an increase in your weight!