These days, everywhere you go, including supermarkets and restaurants, you see an increasing number of low-carbohydrate products. People with diabetes are advised to keep their carb count low to stay healthy. But weight-loss diets that limit carbohydrates have become so popular that now roughly one out of every five Americans counts carbs, regardless of whether they're diabetic. How did carbohydrates get such a bad rap? Find out how much you know about carbs.