Nutrition is the process of getting food into your body and using it as raw materials for growth, fuel for energy, and vitamins and minerals that keep your body healthy and functioning properly.
Macronutrients - Carbohydrates, Fats, and Protein
The foods you eat provide the energy your body needs to function. Just like you need to put fuel in your car or recharge your cell phone battery, your body needs to be fed energy-providing foods every day.
Carbohydrates are broken down into individual glucose, fructose or galactose units. Glucose is your body's favorite form of energy. If you don't get enough carbohydrates, your body can make glucose from protein through a processed called gluconeogenesis, and if you get too many carbohydrates, your body is very good at converting them to fat for storage in your adipose tissue.
Protein comes from the foods you eat and is broken down into individual amino acids. Your body uses the amino acids to build and repair the various parts of your body. Your muscles contain lots of protein, and you need to replenish that protein through your diet. Your body also needs protein for components of your immune system, hormones, nervous system, and organs.
Your body also needs fats to be healthy. Membranes that contain fats surround all the cells of your body. Your brain has fatty acids, and fats are also needed to signal hormones.
Micronutrients - Vitamins and Minerals
The vitamins and minerals you get from your diet are just as important as carbohydrates, protein and fats, even though you only need them in small amounts. They usually function as co-enzymes, which means they help some of your body's chemical reactions happen a lot faster.
For example, many of the B-complex vitamins help burn carbohydrates for energy, vitamin A is needed for vision, zinc is involved in many metabolic processes, and vitamin C helps keep connective tissue strong and your immune system functioning.
Calcium has several functions in your body, but it's best known as the mineral that is stored in your bones and teeth. You need calcium from your diet to keep your bones and teeth strong.
Your diet needs to provide adequate amounts of all of these "little helpers." A healthy, balanced diet will provide you with lots of vitamin and minerals. An unhealthy diet may make your body deficient in one or more of them.
Good nutrition provides more than energy, structural components, vitamins and minerals. There are other substances in the foods that you eat that have become better known over the last few years.
Antioxidants help protect your body from damage that comes from the sun, pollution, smoke, and poor dietary choices. They are found in the phytochemicals of fruits and vegetables, as well as some vitamins and amino acids.
Phytochemicals are antioxidants found in plant-based foods. Although they aren't required for body functioning, they may have a very powerful impact on your health. For example, quercetin (found in red apples) functions like an antihistamine and has an anti-inflammatory effect.
Good Nutrition Means Good Health
A healthy diet will give your body the right amount of energy, enough raw materials and all of the "little helpers" you need to stay healthy. Good nutrition will also provide phytochemicals and antioxidants that will help keep you feeling young, looking great, and perhaps even disease-free.
Gropper SS, Smith JL, Groff JL. "Advanced Nutrition and Human Metabolism." Fourth Edition. Belmont, CA. Wadsworth Pub Co. 2005.