In this chapter, we will briefly discuss the different components of food and nutrition. The topics will include carbohydrates, fats, and proteins, vitamins, minerals, and water, along with guidelines for healthful eating.
Vocabulary
I.
Section 1 vocabulary
1.
Nutrients—substances that the body needs to regulate bodily functions, promote growth, repair body tissues, and obtain energy.
2.
Metabolism—is the chemical process by which your body breaks down food to release this energy.
3.
Calories—the amount of energy released when nutrients are broken down.
4.
Carbohydrates-are nutrients made of carbon, hydrogen, and oxygen which include sugars and starches.
5.
Fiber—is a type of complex carbohydrate that is found in plants
6.
Fats—like carbohydrate, are made of carbon, hydrogen, and oxygen, but in different proportions.
7.
Unsaturated fats—a fat with at least one unsaturated bond in a place where hydrogen can be added to the molecule.
8.
Saturated fats—a fat that has all the hydrogen the carbon atoms can hold.
9.
Cholesterol—a waxy, fatlike substance that is found only in animal products.
10.
Trans fats—the type of fat produced when manufacturers add hydrogen to the fat molecules in vegetable oils.
11.
Protein—a nutrient that contains nitrogen as well as carbon, hydrogen, and oxygen; needed for the growth and repair of body tissues.
12.
Amino acids—Small units that are bound together chemically to form proteins.
II.
Section 2 Vocabulary
13.
Vitamins—Nutrients that are made by living things, are required only in small amounts, and that assist many chemical reactions in the body.
14.
Antioxidants—vitamins that help protect healthy cells from the damage caused by the normal aging process as well as from certain types of cancer.
15.
Minerals—nutrients that occur naturally in rocks and soil.
16.
Anemia—a condition in which the red blood cells do not contain enough hemoglobin
17.
Homeostasis—is the process of maintaining a steady state inside your body.
18.
Electrolytes--- dissolved substances that regulate many processes in your cells.
19.
Dehydration—a serious reduction in the body’s water content.
III.
Section 3 vocabulary

20.
Dietary Guidelines for Americans—a document developed by nutrition experts to promote health and help people reduce their risk for heart disease, cancer, and diabetes through diet and physical activity.
21.
Nutrient-dense foods—foods that contain lots of vitamins and minerals relative to the number of calories.
22.
My Pyramid plan—a plan that groups foods according to types and indicated how much of each type should be eaten daily for a healthy diet.
Carbohydrates, Fats, and Proteins-- section 1
Food Supply Nutrients
Your body needs food, and the food that you eat affects your health in many ways: how you look and feel, how well you resist disease, and even how well you perform mentally and physically.
It does all these things by providing your body with nutrients—substances that the body needs to regulate bodily functions, promote growth, repair body tissues, and obtain energy.
The process by which the body takes in and uses these nutrients is called nutrition.
Food Supply Energy
The foods you eat are your body’s energy source. You rely on energy from food for everything you do:
1.
Running
2.
Playing
3.
Sleeping
4.
Maintaining your body temperature
5.
Keeping your heart beating
6.
Enabling you to understand what you read
Nutrients from the foods you eat provide your body with fuel. This fuel is broken down by way of metabolism to release energy and the amount of energy it releases is measured in units called calories.
The more calories a food has, the more energy it contains.
Have the class look at the calorie content of each food in figure 1 p.193.
For good health, the number of calories in the food that you eat should match the calorie needs of your body; and in addition, you need to consider whether or not the foods you choose contain all the nutrients your body needs.
There are six classes of nutrients: carbohydrates, fats, proteins, vitamins, minerals, and water. Each class of nutrient is necessary for good health.
Carbohydrates, fats, and proteins can all be used by the body as sources of energy; vitamins, minerals, and water perform other essential functions.
Carbohydrates

Carbohydrates are nutrients made of carbon, hydrogen, and oxygen. Carbohydrates supply energy for your body’s functions. There are two general types of carbohydrates: simple carbohydrates and complex carbohydrates.
Simple Carbohydrates
Simple carbohydrates are known as sugars. Sugars occur naturally in fruits, vegetables, and milk. They are added to many manufactured foods, such as cookies, candies, and soft drinks.
There are several types of sugar, but glucose is the most important because it is the major provider of energy for your body’s cells. All other types of sugar are converted to glucose once they are inside your body.
Complex Carbohydrates
Complex carbohydrates are made up of sugars that are linked together chemically to form long chains, something like beads in a necklace.
Starches are one of the main types of complex carbohydrates. They are found in many plant foods, including potatoes and grains. Rice, oats, corn, and wheat are grains. Foods such as tortillas, wholewheat rolls, and Chinese moo shu pancakes are excellent sources of starch.
When you eat foods containing starch, your digestive system breaks the starch into simple sugars that can be absorbed into your bloodstream.
Fiber
Fiber is a type of complex carbohydrate that is found in plants. Strictly speaking, fiber is not really a nutrient because it cannot be broken down and then absorbed into your bloodstream. Instead, fiber passes out of your body without being digested. However, it is still necessary for the proper functioning of your digestive system. A high-fiber diet:
1.
Helps prevent constipation
2.
May reduce the risk of colon cancer
3.
May help prevent heart disease
Whole –grain breads and cereals, vegetables, fruits, nuts, beans and seeds provide fiber in your diet.
Your Body’s Energy Reserves
At meal time, you usually eat more carbohydrates than the body can immediately use. The extra glucose is converted into a type of starch called glycogen, which is stored in your body. When the body needs more glucose, the glycogen is converted back to glucose. If you eat so many carbohydrates that the body’s glycogen stores are full, then the excess carbohydrates are stored as fat instead.
Daily Carbohydrate Intake
Nutritionists recommend that 45 to 65 percent of a person’s daily calorie intake come from carbohydrates. It is better to eat foods rich in complex carbohydrates rather than simple carbohydrates

because simple carbohydrates give quick bursts of energy, while complex carbohydrates provide better long-term, sustained energy.
Fats
Like carbohydrates, fats are made of carbon, hydrogen, and oxygen, but in different proportions. Fats supply your body with:
1.
Energy
2.
Form your cells
3.
Maintain body temperature
4.
Protect your nerves.
Ounce for ounce, fat has twice as many calories as carbohydrates
(One gram of fat equals 9 calories, one gram of protein equals 4 calories, and one gram of carbohydrate equals 4 calories)
Fats come in two forms: Unsaturated and Saturated
Unsaturated fats are usually liquid at room temperature. These fats are found in vegetable oils, nuts, and seeds.
Unsaturated fats are classified as either monounsaturated fats or polyunsaturated fats. Foods that contain monounsaturated fats include: olive oil, peanuts, and canola oil. Foods that contain polyunsaturated fats include safflower, corn, and soybean oil, as well as seafood.
A balanced diet between both monounsaturated fats and polyunsaturated fats is important for cardiovascular health. Unsaturated fats can actually help fight heart disease.
Saturated fats are usually solid at room temperature. Animal fats, such as lard, and dairy products contain saturated fats. Too much saturated fat in your diet can lead to heart disease.
Daily Fat Intake
Nutritionists recommend that 20 to 35 percent of your calories come from fat, primarily unsaturated fat.
Cholesterol
Cholesterol is a waxy, fatlike substance that is found only in animal products. A diet high in cholesterol can increase the level of cholesterol in the blood stream which can develop deposits of plaque on the walls of the blood vessels. Heavy plaque buildup may block blood flow to the heart, depriving the heart of oxygen and leading to a heart attack.
Some research suggests that high blood cholesterol is hereditary. It also has been proven that cholesterol levels tend to rise with age. You may not be able to control that, but what you can control is your diet.
Trans Fats

Trans fats are made when manufactures add hydrogen to the fat molecules in vegetable oils. Foods that contain trans fat stay fresh longer than foods that contain unsaturated fats. Trans fats have few of the benefits of unsaturated fats and many of the risks of saturated fats. Trans fats are found in margarine, chips, and commercially baked goods. The stick margarine contains more than the soft, tub margarines.
Proteins
Nutrients that contain nitrogen as well as carbon, hydrogen, and oxygen are called proteins. Like carbohydrates and fats, proteins serve as a source of energy.
The most important function of proteins, however, is their role in the growth and repair of your body’s tissues.
High-protein foods include meats, eggs, poultry, milk, and milk products. Nuts, dried beans, dried peas, and lentils also contain a lot of protein.
Amino Acids
Like carbohydrates, proteins are long chains of smaller links that are bound together chemically. These smaller substances are known as amino acids.
Essential Amino Acids
The proteins in your body are made up of 20 different amino acids. Your diet has to supply about nine of them, the body manufactures the rest. The nine that the body cannot manufacture are called essential and therefore it is essential to get them in your diet.
Complete and Incomplete Proteins
Protein from animal sources—meats, fish, and so forth—is said to be complete protein because it contains all nine essential amino acid in the proportions needed by your body. In contrast, protein from plant sources, such as beans, is incomplete because it lacks one or more essential amino acids.
Daily Protein Intake
Nutrients recommend that 10 to 35 percent of your calories come from proteins. Simply eat a wide variety of foods, such as red and white meats, fish, dairy products, legumes, nuts, and grains.
Proteins for Vegetarians
People who don’t eat meat can combine two or more plant protein sources that, taken together, provide all the essential amino acids. For example, if you prepared a casserole that contains both rice and beans, the rice and the beans alone would not give you the essential protein that the body needs.
However, when they are combined you form a complementary protein combination.
Section 1 ends
Vitamins

Vitamins are nutrients that are made by living things and are required only in small amounts, and assist many chemical reactions in the body. Unlike carbohydrates, fats and proteins, vitamins do not directly provide you with energy. Instead, vitamins help the body with various processes, including the use of other nutrients. (They help you get the most out of the foods you eat).
Your body is able to make some vitamins. For example, your skin manufactures vitamin D when it is exposed to sunlight. However, most vitamins must be supplied in the food you eat.
There are two classes of vitamins: fat-soluble vitamins, which dissolve in fatty materials, and watersoluble vitamins, which dissolve in water.
Fat-Soluble Vitamins
Fat-soluble vitamins—vitamins A, D, E, and K—occur in vegetable oils, liver, eggs, and certain vegetables.
Look on page 203 at figure 7 to see the fat soluble vitamins and their functions.
Fat- soluble vitamins can be stored by the body.
Water-Soluble Vitamins
Water-soluble vitamins -- include vitamin C and all of the B vitamins—are found in fruits, vegetables, and other sources. Look at Figure 8 on page 204 to see them and their function.
Unlike the fat-soluble vitamins, water-soluble vitamins cannot be stored by the body. Therefore, it is important to eat foods that supply them every day.
Antioxidants
Antioxidants are vitamins that help protect healthy cells from the damage caused by the normal aging process as well as from certain types of cancer. Vitamins C and E are two of the most powerful antioxidants.
Minerals
Minerals are nutrients are required in small amounts. They occur naturally in rocks and soil. Plants absorb minerals from rocks and soil through their roots. Animals obtain these nutrients by either eating the plants or eating animals that have eaten the plants.
Twenty-four different minerals have been shown to be essential for good health.
You need seven mineral-calcium, sodium, potassium, magnesium, phosphorus, chlorine, and sulfur— in significant amounts.
You need only trace amounts of others, such as iron, fluorine, iodine, copper, and zinc.
Minerals perform a wide variety of functions in the body:

Calcium- Calcium is important in blood clotting and the functioning of the nervous system. It is the essential ingredient in the formation and maintenance of bones and teeth. A lack of calcium can sometimes lead to osteoporosis, a condition in which the bones gradually weaken.
Potassium- Potassium and sodium work together to maintain water balance in the body. People who get enough potassium each day usually have a lower blood pressure than those who do not. Foods that are rich in potassium include baked potatoes, spinach, bananas, dried fruits, oranges, soybeans, and tomato products.
Iron
Iron is necessary for healthy red blood cells. These cells have an iron-containing substance called hemoglobin, which carries oxygen from your lungs to all parts of your body. Usually adolescent girls and adult women need extra iron because they lose iron during menstruation.
Sodium
In contrast to calcium, most people consume far more sodium than they need. Table salt, or sodium chloride, is a major mineral source-- salty snack foods, chips, canned soups and frozen pizza.
Vitamin and Mineral Supplements
If a person does not get enough of a specific nutrient, a nutrient deficiency can occur. People who eat a wide variety of healthy foods, however, seldom suffer from nutrient deficiencies. Therefore, vitamin and mineral supplements are not necessary if your diet is nutritious and well-balanced. In fact, an excess or overdose, of vitamins or minerals may damage your health. Some common symptoms of overdose include nausea, vomiting, diarrhea, and rash.
Water p.208
About 65 percent of your body weight is water. You do not get energy from this nutrient directly.
Nevertheless, water is essential for all life processes, including the production of energy. Nearly all of the body’s chemical reactions, including those that produce energy and build new tissues, take place
in a water solution. Water helps regulates body temperature. Water contains dissolved substances called electrolytes that regulate many processes in your cells. And water plays an important role in homeostasis (the process of maintaining a steady state inside your body).
How Much Water?
Girls 14-18—ten 8 ounce cups daily
Boys 14-18—fourteen 8 ounce cups daily
This water can be in the form of foods that contain a lot of water. Try to avoid caffeine products because caffeine increases the amount of water your body excretes.
Water Versus Sports Drinks

Experts in the field of sports medicine recommend 2 cups of fluids 2 hours before exercise, and a drink about every 15 minutes once you start exercising.
Sports drinks are not necessarily better than water if you exercise for 60 minutes or less. If you exercise longer, a sports drink may be beneficial if it contains carbohydrates. However, sports drinks with electrolytes are not necessary unless you exercise for 5 hours or more.
End of Section 2
Guidelines for Healthful Eating—Section 3
Using the food Guidelines
Different food Groups
Grains, Vegetables, Fruits, Oils, Milk, Meats and Beans
Meals- You do not need to consume every food group at every meal. But you should try to vary your diet at each meal.
Breakfast- Don’t skip breakfast. Choose whole grain cereals, low-fat milk or yogurt, and fruit. Limit pastries, eggs, and bacon.
Lunch- Focus on whole grains, fruits, and vegetables. Use mustard or ketchup instead of mayonnaise.
Try low-fat cheese on pizza
Dinner- Trim excess fat from meats. Instead of fried meats or fish, try them grilled. Choose low-fat dressings, and limit butter
Snacks- When snacking, choose foods with high nutrient density.
1.
Try fruit instead of cookies
2.
Make a whole-bagel, not a donut, your after-school treat.
3.
When you go to the movies, choose unbuttered popcorn
Eating Out- When at fast-food restaurants, follow these tips:
1.
Substitute low-fat milk, water, or fruit juice for shakes and soft drinks.
2.
Select the salad bar in place of fries or onion rings. But go easy on the dressings, cheese, bacon bits, and croutons.
3.
Choose a grilled chicken sandwich instead of a burger.