Carbohydrates provide your body with glucose it needs to function properly. Two types of carbohydrates exist: complex carbohydrates and simple carbohydrates. Complex carbohydrates take time to break down into glucose. Foods rich in complex carbohydrates and fiber are called good carbohydrates.Simple carbohydrates include sugars found in foods such as fruits and milk products and sugars added during food processing.Foods rich in white flour and added sugars are called bad carbohydrates.imple carbohydrates include sugars found in foods such as fruits and milk products and sugars added during food processing. Foods rich in white flour and added sugars are called bad carbohydrates.