What are Carbohydrates?
Carbohydrates are the sugars, fibers and starches found in vegetables, grains, fruits and milk products. Though often maligned in trendy diets, carbohydrates are one of the basic food groups and they are important for the body to obtain energy.
In food science and in many informal contexts, the term carbohydrate often means any food that is particularly rich in the complex carbohydrate starch (such as cereals, bread and pasta) or simple carbohydrates, such as sugar that found in candy, jams, and desserts.
Carbohydrates perform numerous roles in living organisms. Polysaccharides (polymeric carbohydrate molecules) serve for the storage of energy (e.g. starch and glycogen) and as structural components (e.g. cellulose in plants and chitin in arthropods). The 5-carbon monosaccharide ribose is an important component of coenzymes (e.g. ATP, FAD and NAD) and the backbone of the genetic molecule known as RNA. The related deoxyribose is a component of DNA. Saccharides and their derivatives include many other important biomolecules that play key roles in the immune system, fertilization, preventing pathogenesis, blood clotting, and development.
Carbohydrates consist of carbon, hydrogen, and oxygen atoms. When combined together to form polymers (chains), carbohydrates can function as long-term food storage molecules, as protective membranes for organisms and cells, and as the main structural support for plants.
Bad Carbohydrates and Good Carbohydrates
Bad carbs (Complex Carbs) are:
High in calories.
Full of refined sugars, like corn syrup, white sugar, honey and fruit juices.
High in refined grains like white flour.
Low in many nutrients.
Low in fiber.
High in sodium.
Sometimes high in saturated fat.
Sometimes high in cholesterol and trans fats.
Examples on Bad Carbs:
- Refined Breads
- Sugared Cereals
- Soda and Sugary Drinks
- Sweet, Candy and Desserts
Good carbs (Simple Carbs) are:
Low or moderate in calories.
High in nutrients.
Devoid of refined sugars and refined grains.
High in naturally occurring fiber.
Low in sodium.
Low in saturated fat.
Very low in, or devoid of, cholesterol and trans fats.
Examples on Good Carbs:
- Bran Cereals
- Green Vegetables
- Fresh Fruits
- Whole Grain Breads
Carbohydrates and Nutrition
Bread, pasta, beans, potatoes, bran, rice, and cereals are carbohydrate-rich foods. Most carbohydrate-rich foods have a high starch content. Carbohydrates are the most common source of energy for most organisms, including humans.
Carbohydrates are not classed as essential nutrients for humans. We could get all our energy from fats and proteins if we had to. However, our brain requires carbohydrates, specifically glucose. Neurons cannot burn fat.
- One gram of carbohydrate contains approximately 4 kilocalories
- One gram of protein contains approximately 4 kilocalories
- One gram of fat contains approximately 9 kilocalories
Most health authorities around the world say that humans should obtain 40-65 percent of their energy needs from carbohydrates - and only 10 percent from simple carbohydrates (glucose and simple sugars).
Healthy Carbohydrates To Add To Your Diet:
1. Start the day with whole grains.
Try a hot cereal, like steel cut or old fashioned oats (not instant oatmeal), or a cold cereal that lists a whole grain first on the ingredient list and is low in sugar. A good rule of thumb: Choose a cereal that has at least 4 grams of fiber and less than 8 grams of sugar per serving.
2. Use whole grain breads for lunch or snacks.
Confused about how to find a whole-grain bread? Look for bread that lists as the first ingredient whole wheat, whole rye, or some other whole grain —and even better, one that is made with only whole grains, such as 100 percent whole wheat bread.
3. Also look beyond the bread aisle.
Whole wheat bread is often made with finely ground flour, and bread products are often high in sodium. Instead of bread, try a whole grain in salad form such as brown rice or quinoa.
4. Choose whole fruit instead of juice.
An orange has two times as much fiber and half as much sugar as a 12-ounce glass of orange juice.
5. Pass on potatoes, and instead bring on the beans.
Rather than fill up on potatoes – which have been found to promote weight gain – choose beans for an excellent source of slowly digested carbohydrates. Beans and other legumes such as chickpeas also provide a healthy dose of protein.
School of Public Health, Harvard University