Simple carbohydrates (refined, processed) are digested quickly and can quickly have an effect on blood sugars in the body. People with diabetes who check blood sugars regularly can tell you that things like juice, sweets, candy, sugary drinks, and refined grains (white rice, white bread) will show up in their blood glucose levels for the day. Simple carbohydrates can also impact your Triglycerides (a type of fat found in your blood). A diet that regularly includes simple carbohydrates can cause high levels of triglycerides which negatively impacts your heart health.
Complex carbohydrates (whole, natural) contain more fiber and take longer for your body to digest. Complex carbohydrates include whole grains (100% whole wheat bread, oatmeal, brown or wild rice, whole wheat pasta), fruits and vegetables, and beans (black beans, etc). These foods do not cause a rapid rise in blood sugars, they also help to improve cholesterol numbers and heart health.
Now, let’s think about the practical ways to get these complex carbohydrates into your daily habits. The current recommendation is to make half or more of your grain choices from whole grains. Look for the “Whole Grain Stamp” (see picture below) on a product which means that it has at least 8 grams of whole grains per serving. Grains (bread, cereal, crackers) that have 100% whole wheat/whole grain on the label are also a clue that it is a complex carbohydrate. Work on eating fresh fruits and vegetables with meals and for snacks. As much as possible, limit refined grains that contain added solid fats, added sugars, and sodium.
Source: www.wholegrainscouncil.org