Download What are carbohydrates

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Some dietary guidelines related to this unit:
 Choose a variety of grains daily, especially whole grains.
 Choose a variety of fruits and vegetables daily.
 Choose beverages and foods to moderate your intake of sugars.
1. What are carbohydrates?
Carbohydrates are made from three main elements—carbon, hydrogen, and oxygen. In fact, the word
“carbohydrates” is a combination of these three chemical names. Carbohydrates exist in many foods. This
is because carbon, hydrogen, and oxygen are very common elements.
As a rule, carbohydrates come from plant sources—grains, fruits, and vegetables. Apples and pears
supply carbohydrates. So do grains—such as wheat, rye and oats—and vegetables such as squash.
Just as your body breaks down protein into usable parts—amino acids—it also breaks down
carbohydrates into basic parts. These parts are sugars, starches, and fiber.
2. Carbohydrates at work
The first and most important job of carbohydrates is to supply energy.
Carbohydrates help your body use protein well. If you do not get enough energy from carbohydrates, your
body will start using stored fat and body protein for energy. Since the major function of protein is to build,
maintain, and repair tissue, depleting the body’s supply to get energy is not healthful. Getting enough
carbohydrates in your diet leaves protein free to do its job. In addition, the carbohydrate fiber helps keep
your digestive system working well.
3. More power to you
Most of your energy comes from the carbohydrates sugar and starch. Your body breaks these substances
down into simple sugars. These simple sugars supply energy. This energy is measured in calories. A
calorie is a unit of heat—the amount of heat it takes to raise one kilogram of water one degree Celsius.
Proteins, fats, and carbohydrates all supply calories. Proteins and carbohydrates both supply about
four calories per gram. Fats supply about 9 calories per gram. Your energy comes from calories. You burn
up calories constantly, whether you are sleeping, reading, swimming, or playing ball. Any calories over the
amount you need are stored in the body as fat.
One way to get all the nutrients your body need is to choose carbohydrates that supply other
nutrients as well. Fruits and vegetables provide vitamins and minerals. Grains provide plant proteins,
vitamins and other nutrients. Such foods are called complex carbohydrates. Complex carbohydrates supply
energy and nutrients at the same time.
4. What are empty calories?
Some foods supply calories and little else. Ordinary table sugar, a carbohydrate called sucrose, is such a
food. It supplies calories but no nutrient except carbohydrate. Fats, such as butter and oil,
Are other such foods, supplying calories, the nutrient fat, and little else.
Foods that are high in fats, carbohydrates, or both and low in other nutrients may give you quick
energy that lasts a short time. Examples of such foods are candy and soft drinks. The calories in these
foods are empty.