Carbohydrates are utilized by the body as its main source of energy. The brain depends ONLY on carbohydrates for energy. Carbohydrates are found in a variety of foods such as fruits, vegetables, grain products and sweeteners. There are three types of carbohydrates:
Simple and complex carbohydrates are broken down in the intestine and converted to glucose in the liver, a sugar that is carried through the bloodstream to cells, where it is used for energy. Some glucose is converted into glycogen, which is stored in limited amounts in the liver and muscles to meet future energy needs. Carbohydrates are converted into fat when intake exceeds your immediate needs and your body’s capacity to store glycogen. Ingestible carbohydrates are also referred to as fiber. The body is unable to breakdown fiber; therefore, it is not considered an energy source.
Fats and Oils
All fats are combinations of saturated and unsaturated fats. They are vital and give your body energy and support cell growth. They also help protect your organs and help keep your body warm. Dietary Fats help your body absorb some nutrients and produce important hormones. Since the body cannot manufacture all the types of fats it needs, certain ones must be eaten; these are referred to as essential.
Proteins are substances that make up your muscles, bones, cartilage, skin, and antibodies, as well as, some of the hormones and all of the enzymes in your body. Proteins in food are broken down in the intestine into amino acids, the building blocks of proteins in your body. The body can manufacture 13 of the 22 amino acids present in proteins; these 13 are called nonessential amino acids because they do not need to be obtained from the diet. The other nine are known as essential amino acids because they must be supplied by food. Certain dietary lifestyles such as vegetarians and vegans need to pay close attention to food choices to ensure that all nine essential amino acids are obtained as part of a comprehensive diet from plant-based foods.