In addition to looking at the ingredient list for added sugar, check the grams of sugar per serving size on the nutrition label. Divide the grams of sugar by 4 and you can determine how many teaspoons of sugar are present in a single serving.
Sugar is added to many, many pre-packaged foods. You might not guess that there is sugar in your blue cheese dressing, your soup or your pasta sauce.
Never assume any processed food is sugar-free until you verify for yourself.