HEALTH: NUTRITION Chapter 7 Section 1

Historical Use of Food: The original need for food was for survival only. [Hunting, Fishing, Scavenging]

Acquired Experiences with Food: Why do you choose the foods you eat? Why do you like one food while your best friend likes another? Have you ever stopped to think why you and your family eat the type of food that other people eat, such as food that is popular in another country? Most people select the type of food they eat with little thought. We have been conditioned to like food our families prepare without having the opportunity to make decisions about those foods. Our ethnic background is a strong factor. Lifestyle also determines what you eat (money, time, and schedules).

What is Nutrition? Nutrition is the science or study of food and the ways in which the body uses food. It is also the study of how and why we make food choices. Nutrition is also the study of the nutrients foods contain.

Nutrients are substances in food that provide energy or help form body tissues and are necessary for life and growth.

Six Classes of Nutrients : Energy Providing: 1. Carbohydrates 2. Fats 3. Proteins

Do not provide energy but are needed for the body to function normally: 4. Vitamins 5. Minerals 6. Water

Carbohydrates- are a class of energy-giving nutrients that includes sugars, starches, and fiber. There are two basic types of carbohydrates: simple and complex.

Simple: made up of single or double sugar molecules; include Glucose (blood sugar), Fructose (fruit sugar), Lactose (milk sugar), and Sucrose (table sugar found in candies and baked goods) -remember all end in –ose

Complex: made of many sugar molecules that are linked together; include starch (potatoes, beans, grains), glycogen (your body’s quick energy reserve), and fiber (fruits and vegetables, cannot be digested by humans, needed for a healthy digestive system, helps prevent colon cancer)

45-65% of the calories in your diet come from carbohydrates

Fats- are a class of energy-giving nutrients and are the main form in which energy is stored in the body. You need fat in your diet for your body to function properly! Fats also add to the texture, flavor, and aroma of our food. But eating too much fat and eating the wrong kinds of fat can increase your risk of weight gain, heart disease, and cancer.

Fats belong to a class of chemical compounds called lipids. Lipids do not dissolve in water. Saturated Fats- made up of saturated fatty acids HEALTH: NUTRITION Chapter 7 Section 1

If you eat a lot of meat, whole milk, butter, and ice cream, your diet will be high in saturated fat. This type of diet can cause weight gain and can increase your blood cholesterol levels and your risk of heart disease.

Unsaturated Fats- made up of unsaturated fatty acids (chain of carbon atoms with one or more double bonds between the carbon atoms-carbon atoms do not hold the maximum number of hydrogen atoms that is chemically possible)

They are more common in plants.

Monounsaturated Fats- found in olive oil, canola oil, and peanut oil Believed to lower the risk of heart disease

Polyunsaturated Fats- corn oil, sunflower oil, soybean oil; a polyunsaturated fatty acid is omega- 3 and is found in seafood and some vegetable oils; they may provide extra protection against heart disease

Trans fats- unsaturated fatty acids that are formed when vegetable oils are processed into margarine and shortening. They may increase the risk of heart disease.

Total fat intake for teens should be 25-35% of total calorie intake with limited amounts of saturated fat, cholesterol, and trans fat.

Cholesterol is another type of lipid. It is found in all human and animal tissues. It is needed to make vitamin D, cell membranes, and certain hormones. Your body makes cholesterol, but you also get it from your diet.

Two kinds: Low-density lipoprotein (LDL) - “the bad kind” brings cholesterol to the body cells. When levels of LDL cholesterol in the blood get too high, deposits called plaque form on the walls of the blood vessels. Plaque can block blood flow to the heart muscle. Lack of blood flow starves the heart muscle of oxygen, causing a heart attack.

High-density lipoprotein (HDL) – “the good kind” carries cholesterol back to the liver, where it is removed from the blood. High levels of HDL are linked to a reduced risk of developing heart disease.

Remember: Cholesterol is found only in animal tissue, so dietary cholesterol is found only in foods such as meat, poultry, fish, eggs, and dairy products. Cholesterol is not found in plants, so foods that come from plants are cholesterol free.

Proteins- are a class of energy-giving nutrients made up of amino acids, which are needed to build and repair body structures and to regulate processes in the body. Your muscles, skin, hair, and nails are made up of mostly protein. Proteins in the body help build new cells and repair existing ones. Protein is also needed to form hormones, enzymes, and antibodies. If you eat more protein than is needed for these essential functions, it can be stored as fat. MYTH: Eating extra protein is important if you want to build bigger muscles. FACT: Muscles grow in response to strength training, not to an increase in protein intake. HEALTH: NUTRITION Chapter 7 Section 1

Proteins are made up of chains of molecules called amino acids. The amino acids are linked together like beads on a necklace to make each type of protein.

Twenty (20) different amino acids make up body proteins. Nine (9) of the amino acids needed to make body proteins cannot be made in our bodies. These amino acids are called essential amino acids. Think of this: it is essential that we eat certain foods to gain these amino acids because our body cannot make them.

The other eleven (11) amino acids can be made by the body and are called nonessential amino acids. They are nonessential because we don’t have to worry about consuming them; our body handles it on its own.

Complete Vs. Incomplete Protein Protein in our diet comes from both animal and plant foods. For the body to maintain itself and grow, these proteins must provide all of the essential amino acids.

Animal proteins such as meat, eggs, and dairy products contain all the essential amino acids. These proteins are therefore called complete proteins.

Most plant proteins, found in foods such as grains and vegetables, have smaller amounts of some essential amino acids. These proteins are called incomplete proteins because they don’t contain ALL of the essential amino acids.

10-35% of your total calorie intake should be from protein