Carbohydrates supply the body with the energy it needs to function. They are found almost exclusively in plant foods, such as fruits, vegetables, peas, and beans. Milk and milk products are the only foods derived from animals that contain a significant amount of carbohydrates.
Carbohydrates are divided into two groups, simple carbohydrates and complex carbohydrates. Simple carbohydrates, sometimes called simple sugars, include fructose (fruit sugar), sucrose (table sugar), and lactose (milk sugar), as well as several other sugars. Fruits are one of the richest natural sources of simple carbohydrates.
Complex carbohydrates are also made up of sugars, but the sugar molecules are strung together to form longer, more complex chains. Complex carbohydrates include fiber and starches. Foods rich in complex carbohydrates include vegetables, whole grains, peas, pasta, potatoes and beans.
Carbohydrates are the main source of glucose, which is a major fuel for all of the body’s cells and the only source of energy for the brain and red cells. Except for fiber, which cannot be digested, both simple and complex carbohydrates are converted into glucose. The glucose is then either used directly to provide energy for the body, or stored in the liver for future use. When a person consumes more calories than the body is using, a portion of the carbohydrates consumed may also be stored in the body as fat.
When choosing carbohydrate-rich foods for your diet, always select unrefined foods such as fruits, vegetables, peas, beans, and whole-grain products, as opposed to refined, processed foods such as soft drinks, desserts, candy, and sugar. Refined foods offer few, if any, of the vitamins and minerals that are important to your health. In addition, if eaten in excess, especially over a period of many years, the large amounts of simple carbohydrates found in refined foods can lead to a number of disorders, including diabetes and hypoglycemia (low sugar). Yet another problem is that foods high in refined simple sugars often are also high in fats, which should be limited in a healthy diet.
Carbohydrates are the best fuel for athletes because they take less oxygen to burn than protein or fat. You’ll be able to exercise harder, both during training and competition, when you eat enough carbohydrates. Each gram of carbohydrate provides 4 calories.
A high carbohydrate diet allows you to train harder by rebuilding your carbohydrate stores and decreasing your recovery time. Your training diet is particularly important because if you can train harder, you can achieve higher levels of performance during competition. Everyone should get 50 to 60 percent of their calories from carbohydrates. As an athlete, you need even more: 60 to 70 percent of your calories, or 3 to 5 grams of carbohydrate per pound of body weight. If you are an endurance athlete, your carbohydrate needs could be as high as 70 to 90 percent of your calories.
Skipping meals will deplete your carbohydrate stores and drain your energy. Similarly, if you fill up on a lot of high-fat and high-protein foods instead of carbohydrates, you won’t have the energy to train and compete at your best.
So as you can see we need carbohydrates because they supply us with energy. They are found in plants.