Chapter 14HEALTHFUL EATING14-1 NUTRIENTS AT WORK FOR YOU

SECTION 14-1O EXPLAIN THE IMPORTANCE OF

CHOOSING NUTRITIOUS FOODS.

O IDENTIFY GOOD FOOD SOURCES OF VARIOUS NUTRIENTS AND DESCRIBE HOW YOUR BODY USES THEM.

Nutrients at work for you

O Nutrients are chemical substances from food, which the body uses to function properly.

O After your body digests food, your bloodstream absorbs nutrients from the digestive tract and carries them to body cells.

14-1O Nutrition is the science of how nutrients

support the bodyO The nutrients that keep your body working

properly are divided into six major classesO CarbohydratesO ProteinsO FatsO MineralsO VitaminsO Water

nutrientsO Each of the nutrients performs

special functions on the bodyO You get different nutrients from

different foods. Therefore you need to eat a variety of foods to get all the nutrients you need.

Carbohydrates

O Carbohydrates are the major sources of energy in your diet

O Most carbohydrates come from plants

O Three kinds of carbohydratesO SugarsO StarchesO Fiber

Carbohydrates

O Sugars are simple carbohydrates found in foods such as milk, fruits, candy, and cookies.

O Your body can use some sugars right away for energy

O Other sugars must first be broken down into simpler sugars

starchesO Starches are often called complex

carbohydratesO Cereals, bread, rice, pasta, and

starchy vegetables are good sources of starch

O Before your body can use starches for energy it must convert the starches into simple sugars during digestion.

StarchesO Nutrition experts recommend most

people get more than half of all their daily calories from complex carbohydrates

FiberO Fiber is a complex carbohydrate.O Fiber provides roughage that

stimulates the normal activity of your intestines.

O Fiber moves food through your body and helps your body get rid of solid wastes

Carbohydrates

O When you eat more carbohydrates than your body can use, some of them are changed to glycogen

O Glycogen is stored in your body for times when you need quick energy such as when you run to catch a bus

O Excess carbohydrates that are not stored as glycogen are changed to fat for storage in the body.

CarbohydratesO You need to eat carbohydrates,

especially complex carbohydrates every day

O A diet low in carbohydrates will not provide the best energy source to fuel

O Your body will use protein for energy instead

O This will deplete protein supplies needed for growth and repair of body tissuses.

ProteinsO Proteins are a nutrient found in every

cell in your bodyO They are needed for growth,

maintenance, and repair of body tissues

O Proteins are made up of amino acids, which are building blocks for your cells

O Your body uses proteins to produce enzymes and hormones

ProteinsO These help the body maintain its

chemical balance and build antibodies to fight infections

O The amount of protein you need depends on several factors

O Without adequate protein, growth is stunted

O You never outgrow the need for protein in your diet

ProteinO Two classes of proteinsO Complete and incomplete proteinsO Complete proteins supply all the

amino acids your body needsO Foods that come from animals, such

as meat, poultry, fish, milk, cheese, and eggs are sources of complete proteins.

Incomplete ProteinsO Incomplete protein sources contain

some, but not all, of the amino acids your body needs.

O Plant sources of protein, such as dried beans, peas, and nuts, provide incomplete proteins.

O When incomplete proteins are combined with complete proteins in a meal, all the needed amino acids are provided.

Incomplete proteinsO Sometimes incomplete proteins can work

together to supply needed amino acids.O Protein foods should be eaten each day.O People whose diets are low in protein

experience poor muscle tone, lack of energy, and reduced resistance to disease.

O Severe protein shortages may result in a disease called kwashiorkor.

O Protein consumed beyond the body’s needs is stored in the body as fat

FatsO Fats are concentrated sources of

food energyO Fat provided slightly more than twice

as much energy per unit of weight as carbohydrates and proteins

O Fats do more than provide energy.O Fat is stored beneath the surface of

the skin to insulate the body from shock and temperature changes.

FatsO Fats protects and cushions the

organs in your body from injuryO Fats are needed in the diet to help

the body distribute and use some vitamins

O Fats also supply essential fatty acids, which are needed for normal growth

Fats

O Two classesO Saturated fats are solid at room

temperature.O Unsaturated fats are most often liquid at

room temperature.O As a rule, foods from animal sources, like

meat and butter tend to be higher in saturated fats

O Foods from plant sources, like corn oil and soybean oil, tend to be higher in unsaturated fats.

FatsO Sometimes manufacturers process

unsaturated fats to make them solid. O This process is called hydrogenation

Cholesterol

O Cholesterol is a fatty substance found in every body cell

O The body uses cholesterol to make a number of important materials, including sex hormones and vitamin D.

O Your body manufactures all the cholesterol you need.

CholesterolO Excessive cholesterol in the blood

can form deposits on the inside of blood vessels.

O This causes the flow of blood to be restricted or blocked completely

O A heart attack can resultO Health experts advise people to limit

their intake of saturated fats and cholesterol.

CholesterolO A diet too low in fat can cause skin

problems and the poor utilization of some vitamins.

O Excessive amounts can cause weight problems

O People who eat excessive amounts of fats tend to eat less of other needed foods.

O Avoid this because a well-balanced diet is important for good health.

Minerals

O Minerals are inorganic substances needed for building tissues and regulating body functions.

O Essential part of bones, teeth, and red blood cells.

O Aid in the proper functioning of muscles and nerves and in the clotting of blood

O Needed for growth and repair of body tissueO Body can absorb minerals directly from the

foods you have eaten.

Calcium and Phosphorus

O The most abundant minerals in the bodyO Reserves are stored in the bonesO Also found in teeth, soft tissues, and body

fluids.O Calcium is used to regulate the use of other

minerals in the bodyO Without calcium the blood will not clot.O Calcium also helps the nervous system to

functionO All muscles are dependent on calcium for

their activity

Calcium and Phosphorus

O A diet low in calcium intake over a long period could lead to osteoporosis

O This is a disease characterized by weak, brittle bones, which are more likely to fracture.

O Milk is an excellent source of calcium, other sources are yogurt, cheese, pudding, and dark green leafy vegetables.

O Foods that are high in protein are also good sources of phosphorus.

Fluorine

O Fluorine is needed for the proper development of bones and teeth.

O Helps reduce tooth decayO Not readily available in foodsO Some cities add fluorine to the

supply of drinking water

IodineO Iodine is present in very small amounts in

the body, but it is essential for good healthO Iodine is used to make thyroxineO Thyroxine is a hormone produced by the

thyroid gland O Thyroxine controls the rate at which the

body uses nutrientsO When the diet is low in iodine, the thyroid

gland enlarges, this condition is called a goiter.

IronO Iron is another essential mineralO Iron combines with protein to make

hemoglobin.O Hemoglobin is a substance in the

blood that carries oxygen from the lungs to cells throughout the body.

O A diet that is constantly low in iron results in a condition known as iron-deficiency anemia

IronO Foods rich in iron include organ

meats, lean meats, dried beans and peas, dark green leafy vegetables, and eggs

O Women generally require more iron than men

O To meet their needs, some women may need to take iron supplements prescribed by a doctor.

Sodium

O Sodium works with other minerals to help maintain the balance of fluids in the body.

O Also play a role in transmitting nerve impulses to the brain.

O Diets high in sodium are linked with high blood pressure.

O The main sources of dietary sodium are table salt and processed foods

ZincO Zinc has a number of functions in the

body:O It is important for normal growth and

developmentO Helps the immune system work properlyO Helps wounds healO Too little zinc in children can stunt growthO An excess can be toxicO Meat, fish poultry, whole grains, and

some legumes are good sources of zinc.

Other mineralsO The body needs a number of other

minerals to maintain good health O These include copper, potassium,

chlorine, magnesium, and seleniumO Each of these minerals performs

specific functions.O Eating a variety of foods is the best

way to make sure you get all the minerals you need.

Vitamins

O Vitamins are organic substances needed in small amounts for normal growth and the maintenance of good health.

O Regulators of body processes necessary to enable the other nutrients to do their work

Vitamins

O Divided into two groups:O Fat-soluble these vitamins that can

be stored in your body in fatty tissues and in the liver

O Fat –soluble vitamins are A, D, E, and K.

Vitamin AO Vitamin A is needed for good vision, normal

growth and healthy skin.O A deficiency of vitamin A can cause night

blindness and drying of the eyes and skin.O Night blindness occurs when the eyes cannot

adjust from bright to dim lightO Excesses of vitamin A from food are not common,

if gotten from pill form individuals may experience fatigue, headaches, and vomiting.

O Good sources of vitamin A are liver, whole and fortified milk products, and fish oils.

O Carotene is also a good source of Vitamin A

Vitamin D

O Vitamin D helps your body absorb calcium and phosphorus and deposit them into cells.

O Vitamin D works with calcium and phosphorus to form and maintain bones and teeth

O A prolonged shortage of vitamin D in the diets of growing children can cause weakened bones.

O Extreme shortages can result in a condition called rickets.

Vitamin DO Extra vitamin D is stored in the bodyO Excessive amounts of vitamin D may

cause diarrhea, nausea, and headaches.

O Vitamin D is often called the “sunshine vitamin” because your body can manufacture vitamin D when your skin is exposed to sunlight

O Fortified means nutrients have been added to a food to improve its nutritional value.

Vitamin EO The main function of vitamin E in the

human body is to act as an antioxidant.O This is a substance that protects

compounds from the damaging effects of oxygen

O Vitamin E protects blood cells and cells in the lungs from oxygen damage.

O Vitamin E is found in vegetable oils, whole grain cereals, liver, and green leafy vegetables.

O Rarely deficiencies

Vitamin KO Vitamin K is needed for proper blood

clottingO Vitamin K deficiencies are not

common because vitamin K is widely available in most diets.

O A severe deficiency could cause bleeding, but deficiencies are rare.

O Excesses are also rare, they can be toxic.

Water-Soluble VitaminsO The second group of vitamins is the

water-soluble vitamins.O These vitamins are not stored in the

body to a great extent.O Excess amounts of water-soluble

vitamins are excreted in the urine.O You need to eat good sources of

these vitamins every day.

Water-Soluble vitaminsO The B vitamins and vitamin C are

water-soluble vitamins.O These vitamins can be lost during

cookingO This is why it is a good idea to cook

most foods quickly, using as little water as possible

O After cooking do not throw away cooking liquid, instead save it for use in a sauce or soup.

Vitamin BO The B vitamins are a group of

vitamins that are similarO However each vitamin in this group

plays its own role in helping your body function properly

O Thiamin, riboflavin, and niacin, folate, vitamin B12 are member of this vitamin group.

Thiamin

O Thiamin helps you obtain energy from the foods you eat

O It is important in promoting a normal appetite and good digestion

O Helps the nervous system function properlyO A deficiency of thiamin can result in nausea,

depression, loss of appetite, and fatigue.O A severe deficiency can lead to aa disease

called beriberiO This disease causes numbness in the ankles and

legs and leads to paralysis and heart failure

Thiamin

O Good sources of thiamin include pork, legumes, and whole grain and enriched grain products.

O Enriched means nutrients that were lost during processing have been added back into a product.

Riboflavin

O Riboflavin is needed by your body to obtain energy from foods.

O Needed for healthy skin and normal vision

O Deficiency can cause cracked lips, a skin rash, and extremely sensitive eyes

O Best sources are dairy products, meats, and leafy green vegetables.

NiacinO Needed to help you obtain energy from

foodsO Also needed for healthy skin, good

digestion, and proper functioning of the nervous system.

O A deficiency of niacin can cause pellagra which affects the skin and digestive system.

O Good sources of niacin include meat, poultry fish, nuts, dried beans, and whole grain and enriched grain products.

FolateO Used for making all new cellsO This function has a special significance

for pregnant women.O The spine and brain if a baby growing in

its mother’s womb may not develop properly if the mother’s diet lacks folate.

O Damage to the spine and brain can occur in the first few weeks of pregnancy.

O This is before most women even know they are pregnant.

FolateO Therefore, all women of childbearing

age are urged to be sure they are meeting their folate needs.

O Fresh fruits and vegetables especially leafy green vegetables are good sources of folate.

Vitamin B12

O Helps the body make red blood cells.O Protects nervesO A vitamin B12 deficiency can result

in anemia and nerve damageO Naturally occurs only in foods of

animal origin, such as meat, fish, poultry, eggs, and dairy products.

Vitamin CO Helps hold body cells together and keeps the

walls of the blood vessels strongO Important in the healing of wounds, also helps

you body fight infectionO A lack of vitaminC over time may result in

bleeding gums, loose teeth, bruising, and sore joints.

O A severe deficiency of vitamin C and lead to a disease called scurvy.

O Sources of vitamin C citrus fruits, strawberries, cantaloupe, peppers, broccoli, and tomatoes.

WaterO Water is one of the most important

nutrientsO Over half of the body’s weight is

waterO As a basic part of blood and tissue

fluid, water helps carry nutrients to the cells

O Water also carries waste products from the cells

O Water aids in digestionO Water regulates body temperature

Water

O You should try to drink six to eight glasses of water each day

O Get additional water from the foods you eatO Soup, watermelon, tomatoes, and even

breads and meats contain water.O Water is also a product of chemical reaction

that take place in your bodyO You can get water your body needs from

drinking other beverages in addition to water

Water

O Limit amounts of beverages high in sugar, these promotes tooth decay and may be a source of excess calories,

Recommended Nutrient Intakes

O To help you determine your daily nutrient needs, the Recommended Dietary Allowances were established in 1941.

O From time to time these are revisedO These four types of values are jointly called

Dietary Reference Intake(DRI) O Outline nutrient requirements for each sex and

for several age groupsO Allowances include needs for energy, protein,

and many vitamins and mineralsO Designed to meet the needs of healthy people.

14-2O Plan a well-balanced diet based on

MyPlate

O List the Dietary Guidelines for Americans.

The Dietary Guidelines for Americans

O To help people choose healthful diets the U.S. Department of Agriculture and Health and Human Services have suggested Dietary Guidelines for Americans

O Aim for a healthy weightO Be physically active each dayO Let the pyramid guide your food choicesO Choose a variety of grains daily, especially

whole grainO Choose a variety of fruits and vegetables dailyO Keep food safe to eat

Dietary GuidelinesO Choose a diet that is low in saturated

fat and cholesterol and moderate in total fat

O Choose beverages and foods to moderate your intake of sugars

O Choose and prepare foods with less salt

O If you drink alcoholic beverages, do so in moderation

14-3Nutritional Needs ChangeO Identify dietary needs of people in

different stages of lifeO Describe special nutrient needs of

athletes

Nutritional needs change

O All people need the same nutrients.O The amounts needed vary from

person to personO Women need more iron than menO Nutritional needs vary with age as

well as with gender, body size, activity level, and health.

O Needs change throughout life cycle

Needs of pregnant women and infants

O Nutritional needs begin before birthO Pregnant women must eat foods that

will supply nutrients for their babies as well as for themselves

O Once babies are born they have tremendous nutrient needs to support their rapid growth

Nutrition before BirthO Well-balanced diet O Consuming two to three daily servings

from the milk group will provide the calcium needed during pregnancy

O Two added servings from the grainO Plenty of fruits and vegetablesO Doctors may prescribe nutrient

supplements to help meet increased needs during pregnancy.

Nutrition in InfancyO Every part of a child’s body grows

and develops most rapidly during the first year of life

O Good nutrition is most important during this year to build a strong foundation for a healthy lifetime. Breast milk or formula is a baby’s first food.

O Vitamin C, vitamin supplements at about 6 to 8 months

Needs of Children and Teens

O As children grow their nutritional needs continue to change.

O Food preferences also changeO Caregivers must help children select

a variety of well-liked foods from each of the food groups.

Nutrition during the preschool years

O Preschool children need larger proportions of nutrients to support their rapid growth.

O Caregivers need to make a special effort to include vitamins A and C, raw fruits and vegetables, offer healthy snacks, cheese cubes, cereals, and crackers spread with peanut butter

Nutrition During the Early School Years

O A nutritious energy-packed breakfast is needed to help children stay alert in class

O Children may sometimes need to bee encouraged to eat well-balanced lunches in the school cafeteria

O Need energy provided by milk, breads,, meats, fruits, and vegetables

Nutrition during the Teen Years

O Period of rapid growthO Meals and snacks for teens need to

be carefully plannedO They must provide all the nutrients

needed for growth and maintenance of strong healthy bodies.

O Foods must also supply enough energy to meet a teen’s high level of activity

Vegetarians dietO This is a pattern of eating that is made up

largely or entirely of foods from plant sources.

O Vegans consume no foods of animal originO Lactovegetarians exclude meat, poultry,

fish, and eggs but include dairy productsO Ovo vegetarians omit meat, poultry, fish,

and dairy products but include eggs.O Lacto-ovo vegetarians do not eat meat,

poultry, or fish. However, they include eggs and dairy products in their diets

Special needs of athletes

O Increase daily calorie intakeO Drink plenty of fluidsO Eat plenty of iron-rich foodsO Meet daily calcium needs

Needs of adultsO Gradually, metabolism begins to

slow causing adults to need fewer calories

O Decrease their food intake so they do not gain weight

O Need for nutrients during adulthood does not diminish along with the need for calories

O Meals and snacks for adults need to include foods that will supply nutrients along with calories.

Nutrition for Older Adults

O Need for calcium actually increases for adults over age 50

O Physical changes caused by the aging process can affect the eating habits of older adults.

O Foods remain appealing

Nutrition needs of People who are Ill

O Replace lost fluids,O Additional proteinsO Vitamins and minerals, such as

Vitamin C, and zincO Some illness may be prescribed a

diet by doctors and registered dieticians.

Section 14-4O Balancing Calories and Energy NeedsO Identify factors that affect energy

needs for metabolic and physical activity

O Outline guidelines for healthy weight loss and healthy weight gain

O Describe two common eating disorders

Balancing Calories and Energy Needs

O Energy is needed to support every activity to your body

O You obtain needed energy from carbohydrates, fats, and proteins, in the foods you eat

O This food energy is measured in units called calories

O Learning to balance your calorie intake against your calorie needs will help you maintain a healthy weight

Meeting Energy NeedsO People differ in their energy needs O Needs are based on a person’s age,

sex, body type or size, and level of physical activity

O The body needs energy to support both metabolic and physical activity.

Metabolic energy needs

O Even when you sleep your body is still working, heart pumping, lungs drawing oxygen, your tissues are being built and repaired.

O These life-sustaining activities are collectively called basal metabolism

O Basal metabolism accounts for the energy required when your body is at physical, emotional, and digestive rest.

Metabolic Energy Needs

O The basal metabolic rate(BMR) varies greatly from person to person

Energy for Physical Activities

O Physical activity raises energy needs above basal requirements

O The amount of energy you need is related to the amount of work you do

O If your level of physical activity is light you will need fewer calories to fulfill your energy needs

Controlling your weightO Weight management involves both

eating and physical activity.O The foods you eat give your body

energy, O To control your weight you need to

compare the calories you eat to the calories you burn

O How much should your weight?O Based on body frame bone structure

Healthy Weight LossO Most people gain weight because

they consume more calories than they burn

O Excess calories are stored as fat, as fat stores accumulate, weight gain occurs

O Obesity is one of today’s major health problems.

O High blood pressure, diabetes, and heart disease, negative impact on a person’s self-concept.

Guidelines healthy weight

O Try to maintain a balance between food intake and physical activity

O Try to spend at least 60 minutes each day in moderate physical activity

O Base your diet on grains, vegetables, and fruits.O Avoid omitting any group of foods from your dietO Avoid making drastic changes in your food

intake without the advice of your doctorO Beware of fad diets that focus on one or two

foods.

Eating disordersO Eating disorder is an abnormal eating pattern

that actually threatens a person’s health.O Anorexia nervosa is an eating disorder in

which a person avoids eating, sometimes to the point of starvation.

O Bulimia nervosa is also known as the binge-purge syndrome

O People who have this disorder go on eating binges and consume excessive amounts of calories. They then take steps to avoid weight gain.

Eating DisordersO Earlier eating disorders are detected

the better the chances victims have of recovering with no serious medical problems

O Treatment of an eating disorder may involve a team of health professionals.