Foods darker in color, such as whole-grain bread, should be chosen and lighter-colored foods, such as white sandwich bread, should be avoided. 

Fat makes food dense, and thus foods high in fat should be avoided

Foods with a lot of nutrients per calorie, such as fish, are more nutritious choices than foods with few nutrients per calorie, such as candy, which should be limited. 

Dense foods, such as peanut butter or chicken, are more nutritious choices than transparent foods, such as fruit juice or candy, which should be limited.