Carbohydrates are one of the three macronutrients (along with proteins and fats) which make up our foods. They are essentially sugar molecules in various combinations. The word carbohdyrate comes from the carbon, hydrogen, and oxygen atoms which make them up, such as this model of a glucose molecule. Up until about 10-15 years ago, that was about it. (More about the structure of carbohydrates from Regina Bailey, About.com's Guide to Biology)
Since that time, there has been a gradual shift, first towards calling high-carb foods "carbohydrates." It started out innocently enough -- potatoes, rice, and bread were "carbs" because they were made up mostly of starchy carbohydrates. Next, there were "good carbs" and "bad carbs," although the definitions of these varied depending upon who was describing them. More recently, any food that has any carbohydrate at all is sometimes called a "carbohydrate," even if it doesn't have much (spinach is now apparently a "carb" by that definition). Similarly, the term "simple carbohydrate" (which used to mean "sugar") has morphed into meaning almost the same as "refined carbohydrate," or the foods which contain them. This could be a sugar or a starch -- I've seen white bread called a simple carbohydrate. "Complex carbohydrate" (which used to mean either "starch" or "fiber") is now often used to mean whole foods that contain carbohydrate, even if they contain no starch at all (e.g. watermelon).
Are you confused yet?
This mess has led to statements in the media such as "carbohydrates are a good source of vitamins and minerals." This is enough to make me want to tear out my hair -- it's what science writer Michael Pollan calls "nutritionism" at its worst. I propose that it's much more helpful to think in terms of actual food. Food has vitamins, and food has carbohydrates, but carbohydrates do not have vitamins. There is no room in a molecule of carbohydrate for a vitamin.
What you Need to Know
- Some foods are high in carbohydrate - sugar-sweetened foods, starchy foods, dried fruit, etc.
- Some foods are low in carbohydrate - protein foods, non-starchy vegetables, low-sugar fruits, oils, etc.
- By and large, the plant foods that have the most carbohydrate have the lowest concentrations of vitamins and minerals. Even valuable phytonutrients tend to be more highly concentrated in vegetables and fruits with low amounts of carbohydrate. Obviously, there are exceptions to this, but it's reassuring to know that low-carb foods are often very high in nutrients.
- To get the most nutrition for the least carbohydrate, try this guide, and/or my Low-Carb Food Pyramid.
