Ch. 7 Nutrition for Life

Section 1 Carbohydrates, Fats, and Proteins

Section 2 Vitamins, Minerals, and Water

Key Terms

• Nutrition: the science or study of food and the ways in which the body uses food

• Nutrient: a substance in food that provides energy or helps form body tissues and that is necessary for life and growth

• Carbohydrate: a class of energy giving nutrients that includes sugars, starches, and fiber

• Fat: a class of energy giving nutrients; also the main form of energy storage in the body

• Protein: a class of nutrients that are made up of amino acids, which are needed to build and repair body structures and to regulate processes in the body

Key Terms

• Vitamin: a class of nutrients that contain carbon and are needed in small amounts to maintain health and allow growth

• Mineral: a class of nutrients that are chemical elements that are needed for certain body processes, such as enzyme activity and bone formation

• Nutrient deficiency: the state of not having enough of a nutrient to maintain good health

What Is Nutrition

• Nutrition is the science or study of food and the ways in which the body uses food– Study of how and why we make food choices– Study of the nutrients foods contain

Six Classes of Nutrients

• There are six classes of nutrients in food:– Carbohydrates– Fats– Proteins– Vitamins– Minerals– Water

A Balanced Diet Keeps You Healthy

• To stay alive, healthy, and growing, a person must eat and drink the right amounts of nutrients

• Eating too little food causes weight loss, poor growth, and if severe enough death.

• But eating too much food can also cause illness resulting from excess body fat– Heart disease– High blood pressure– Chronic diseases and disorders linked to poor nutrition

• What you eat today not only affects how you look and feel right now but also can affect your health in the long term

Food Has Fuel for Your Body

• Food provides the fuel that runs your body• The sum of the chemical processes that take place in your

body to keep you alive and active is called metabolism– Requires energy and nutrients

• The nutrients in food that provide energy are carbohydrates, proteins, and fats.

• Vitamins, minerals, and water are also nutrients needed for metabolism, but they do not provide energy.

• The energy in food is measured in calories• The number of calories in a food depends on the amount

of carbohydrate, fat, and protein it contains

Carbohydrates

• Found in foods such as fruit, milk, cookies, and potatoes all which are made of the same thing sugars

• Two types of Carbohydrates:– Simple– Complex

• Simple are made up of single or double sugar molecules

• Complex made of many sugar molecules that are linked together

Simple

• Glucose: a single sugar that circulates in the blood (blood sugar); the most important sugar in the body because it provides energy to the body’s cells; usually found as a part of the double sugar sucrose or in starch

• Fructose: a single sugar that is called fruit sugar; is sweeter that table sugar; found naturally in fruit and honey; added to many sweetened drinks

• Lactose: a double sugar made by animals that is also called milk sugar; found in dairy products

• Sucrose: a double sugar refined from sugar beets or sugar cane that we call table sugar; found in candies and baked goods and used as a table sweetener

Complex

• Starch: made of many glucose units linked together; found in foods like potatoes, beans, and grains

• Glycogen: made in the body; made of many glucose units linked together; stored in the muscle and liver of humans and animals; can be broken down to provide a quick source of glucose

• Fiber: made of many glucose units linked together; found in fruits and vegetables; cannot be digested by humans; needed for a healthy digestive system

Fats

• Is an essential nutrient• You need fat in your diet for your body to function

properly• Add to the texture, flavor, and aroma of food• Belong to a class of chemical compounds called

lipids, which are fatty or oily substances that do not dissolve in water

• Fatty acids are long chains of carbon atoms that are chemically bonded to each other and are attached to hydrogen atoms

Fats• Saturated Fats are fats that are made up of saturated fatty acids

– Solid at room temperature and come from animal foods such as meat and milk

– Meat, whole milk, butter, ice cream • Unsaturated Fats are fats that are made up of unsaturated fatty

acids– Common in plants– Liquid at room temperature

• Cholesterol– Found in human and animal tissues– Needed to make vitamin D, cell membranes, certain hormones, and

bile– LDL “bad cholesterol”– HDL “Good cholesterol”– Found in foods such as meat, fish, poultry, eggs, and dairy products

Four Fat Facts

1. Too little dietary fat can lead to a fatty-acid deficiency, but eating too much of the wrong types of fats can raise blood cholesterol levels

2. Fat in your adipose tissue cushions your body’s organs and helps keep your body temperature stable

3. Fat is needed to make regulatory molecules in the body such as certain types of hormones. Fat is also needed to form the coating on nerves and the membranes that surround body cells

4. Fats add to the taste and texture of food and help you feel full for several hours after you have eaten

Proteins

• Your muscles, skin, hair, and nails are made up of mostly protein• Help build new cells and repair existing ones• Needed to form hormones, enzymes, antibodies, and other

important molecules• Proteins are made up of chains of molecules called amino acids.• 20 different amino acids make up body proteins• 9 of the amino acids needed to make body protein cannot be

made in our bodies called essential amino acids, must be eaten in your diet

• The other 11 can be made by the body and are called nonessential amino acids

Complete and Incomplete Proteins

• 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 legumes, grains, and vegetables, don’t have all the essential amino acids or have smaller amounts of some essential amino acids than are needed by your body. These proteins are called incomplete proteins

Vitamins

• Classified by whether they dissolve in fat or water• Fat-Soluble Vitamins– A, D, E, K– Dissolve in fat, most can be stored in fat tissue and

remain in the body for a long time• Water-Soluble Vitamins– 8 B vitamins and vitamin C– Not stored I the body well– B vitamins do not provide energy, most are needed to

release energy from carbohydrates, fats, and proteins

Minerals

• More than 20 minerals are essential in small amounts to maintain good health

• Mineral are a class of nutrients that are chemical elements that are needed for certain body processes, such as enzyme activity and bone formation

• Review Table 3

Water

• 60% of your body is water• Water is essential because it is necessary for

almost every function that keeps you alive• Extra water cannot be stored in the body,

therefore water intake must balance what your body loses

• Eight glasses a day (2.5 quarts)• Water, juice, and low-fat milk are healthy

sources of fluid

Three Reasons Why Water Is Important

1. It transports nutrients and oxygen through the body and helps get rid of wastes from the body

2. It provides the proper environment for the body’s chemical reaction to occur

3. It helps regulate body tempature