Complex carbohydrates and dietary fiber are very important for our body, Whole grains are an excellent source of these complex carbs and dietary fiber. All types of whole grains are rich in complex carbs and contain bran and endosperm which provide different nutrients needed by our body. Grains like rice, corn, wheat, barley, oats and buckwheat contain carbohydrates. Brown rice contains the highest carbohydrates, 38 mg of carbohydrates per serving. Brown rice is said to provide our body with energy boosting carbohydrates. It also contains a lot of fiber which helps with digestion and bowel movement. Many doctors suggest having whole grain over regular grains as they improve digestive health and help manage weight.