What's been "refined" out of these processed carbohydrates are all the beneficial nutrients that nature originally put into them. The bran, the fiber, and most of the vitamins and minerals have been stripped away, leaving a bland, white, longer-lasting and shelf-stable product. White flour has only 20 percent of the vitamins and minerals and 25 percent of the fiber of the original wheat kernel. That's why a lot of bread products are "enriched" with vitamins and minerals -- they don't contain enough to mention otherwise. Whole wheat flour still contains the hull, germ, and bran of the grain and offers more fiber and nutrients. I look forward to the day when fast-food restaurants offer whole grain buns and fiber-rich side dishes to their customers, instead of the empty carbs that they now push on us so aggressively.

Now that we've talked a little bit about carbohydrates, why don't you take a minute to ask yourself if you might be eating too many of the refined, highly processed variety.

One way to distinguish between carbohydrates that harm us and carbohydrates that heal us is to think about their fiber content. Products that are made out of refined white flour and white sugar usually have very little fiber and are very processed. Fiber-filled carbohydrates are better for you than those with little or no fiber. Fiber provides a barrier for your digestive system -- otherwise the carbohydrates get turned into sugar immediately. Most Americans eat around 12 grams of fiber a day, while the recommended daily intake ranges from 20 to 45 grams. Yet we are overconsuming carbohydrates! Whenever you reach for a box of cereal, a loaf of bread, or any other product made with flour (pastas, etc.), always reach for the brand that lists whole wheat or another whole grain as the first ingredient. And also check the fiber content and go with the one that has the most fiber per serving.

In the last several years, a more sophisticated method has emerged to help us understand which carbs are good and which are bad. This is what is known as the glycemic index, or GI. The glycemic index rates how many readily available sugar is in a particular food. This, in turn, indicates how quickly that food will affect your blood sugar level. White bread, potatoes, and refined cereals, which are rapidly digested, create a surge in blood sugar levels, and so these are classified with high GI ratings. Foods with low GI ratings, such as vegetables, whole grain products, and beans are metabolized more slowly, largely because of their fiber content. These low-GI foods don't cause drastic changes in blood sugar levels and thereby eliminate the highs and lows that can lead to excess snacking and sugar cravings. Making a simple switch in the foods you eat can have a profound effect on your health. For example, eating brown rice instead of white rice will do wonders for controlling your blood sugar level. So will switching from white bread to whole grain bread. Plus, the extra fiber in these foods will expand in your stomach, so you will feel full faster and longer after eating whole grain products. When you're buying whole grain products, continue to be a good food detective and watch out for any ingredients that you are trying to avoid.