Nutrition is the study of foods and how they nourish the body.
Nutrients are food substances that are required for the growth and maintenance of the body’s cells. Each nutrient has a special job to do. Together, they keep you healthy, help you grow, and set the foundation for health and wellness.
Nutrients are divided into two classes: macronutrients and micronutrients. Macronutrients are ones that your body needs in large quantities. Micronutrients are ones your body needs in small quantities.
Let's start with the macronutrients.
Carbohydrates
Proteins
Fats
Water
Carbohydrates provide you with your main source of energy. The two kinds of carbohydrates are simple and complex. Simple carbohydrates, or sugars, are found in fruits, milk, and table sugar. Starchy foods such as bread, rice, pasta, and potatoes contain complex carbohydrates. Your body breaks complex carbohydrates down into simple sugars. Many starchy foods also contain fiber. Raw fruits, raw vegetables, and whole grains contain fiber that your body cannot digest. Fiber supplies no energy but helps carry out waste from your body.
Proteins build, repair, and maintain body cells. They are called the building blocks of your body. Animal products such as milk, eggs, meat, and fish contain proteins. And so do plant products like beans, peas, grains, and nuts.
During digestion, your body breaks down proteins into simpler substances called amino acids. Your body manufactures 11 of the 20 existing amino acids, but you need to get the other nine, called essential amino acids, from food.
Meat and other animal products, such as eggs and dairy products, provide complete proteins. This means that they contain all the amino acids your body needs to build and maintain strong muscles. Individual plant proteins are incomplete proteins. However, by combining certain plant foods such as beans and rice, you can get all the amino acids you need.
Fats are a source of energy. They dissolve certain vitamins and carry them to body cells to help keep your skin healthy. Eating too much fat can cause weight gain and may lead to health problems such as cancer and heart disease.
You may not have thought of water as a nutrient before, but it’s an important one.
Water carries other nutrients to your cells, carries away waste, and regulates your body temperature. Without water, your body would not be able to function.
Throughout the day, you must replace the water your body uses. To do so, you should drink eight to ten 8-ounce glasses of water each day. If you are working or playing hard or are outside in hot weather, you will need to drink even more.
TIP: A good way to remember how much to drink is “8 by 8,” which stands for 8 glasses by 8:00 p.m. Water is the healthiest beverage to drink, but any fluid you consume counts toward your total.
