Nutrition is the science that deals with food and how the body uses it. All living things need food to live. The food supplies energy, which people need to perform certain actions.
Food also provides substances that the body needs to build and repair its tissues and to regulate its organs and organ systems. Food provides certain chemical substances needed in order for a person to maintain good health. These chemical substances are called nutrients. Nutrients can perform three important functions.
They provide materials for building, repairing, or maintaining body tissues.They help regulate body processes. They serve as fuel to provide energy. The body needs energy to maintain all its functions.
People who do not get enough nutrients are sometimes lazy and are unwilling to work. The foods we eat contain thousands of different chemicals. Our body, however, only needs only a few dozen of these chemicals in order to stay healthy. These are the nutrients that the body needs.
Nutrients are divided into six main groups. They are (1)water, (2)carbohydrates, (3)fats, (4)proteins, (5)minerals, (6)vitamins. Water, carbohydrates, fats, nd proteins are called macronutrients.Since macro means large, the body needs these four nutrients in large amounts.
Minerals and vitamins are called micronutrients (because micro means small). The body needs only small amounts of these nutrients. Water is the most important nutrient. Our bodies can survive without other nutrients for several weeks, but we can only go without water for about one week.
Water is needed in great amounts because the body consists largely of water. Between 50 and 75 percent of a normal person’s body weight is made up of water. The body needs water o carry out all of its life processes.Watery solutions help dissolve other nutrients and carry them to all of the tissues.
The body also needs water to carry away waste products and to cool itself. Adults should drink about 2 1/2 quarts of water every day. The carbohydrates, fats, and proteins are needed because they have nutrients which provide energy. Carbohydrates include all sugars and starches.
They are the main source of energy for living things. There are two types of carbohydrates, simple and complex. Simple carbohydrates include sugars and have a simple molecular structure.Complex carbohydrates include starches and have a larger and more complicated molecular structure.
The structure consists of many simple carbohydrates linked together. Fats are a highly concentrated source of energy. All fats are composed of an alcohol called glycerol and substances called fatty acids. A fatty acid consists of a long chain of carbon atoms.
There are three types of fatty acids. They are saturated, monounsaturated, and polysaturated. This is a chart that describes the amount of fat per serving. The bold words can be found on many food products in the supermarket.