Transcript Chapter 14 HEALTHFUL EATING

Chapter 14
HEALTHFUL EATING
14-1 NUTRIENTS AT WORK FOR YOU
SECTION 14-1
O 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.
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O Nutrition is the science of how nutrients support
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the body
The nutrients that keep your body working
properly are divided into six major classes
Carbohydrates
Proteins
Fats
Minerals
Vitamins
Water
nutrients
O Each of the nutrients performs special
functions on the body
O 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
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energy in your diet
Most carbohydrates come from plants
Three kinds of carbohydrates
Sugars
Starches
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
starches
O Starches are often called complex
carbohydrates
O 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.
Starches
O Nutrition experts recommend most people
get more than half of all their daily calories
from complex carbohydrates
Fiber
O 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.
Carbohydrates
O 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.
Proteins
O Proteins are a nutrient found in every cell in
your body
O 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
Proteins
O 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
Protein
O Two classes of proteins
O Complete and incomplete proteins
O Complete proteins supply all the amino
acids your body needs
O Foods that come from animals, such as
meat, poultry, fish, milk, cheese, and eggs
are sources of complete proteins.
Incomplete Proteins
O 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 proteins
O Sometimes incomplete proteins can work
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together to supply needed amino acids.
Protein foods should be eaten each day.
People whose diets are low in protein experience
poor muscle tone, lack of energy, and reduced
resistance to disease.
Severe protein shortages may result in a disease
called kwashiorkor.
Protein consumed beyond the body’s needs is
stored in the body as fat
Fats
O Fats are concentrated sources of food
energy
O 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.
Fats
O Fats protects and cushions the organs in
your body from injury
O 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 classes
O 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.
Fats
O 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.
Cholesterol
O 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 result
O Health experts advise people to limit their
intake of saturated fats and cholesterol.
Cholesterol
O 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
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building tissues and regulating body functions.
Essential part of bones, teeth, and red blood
cells.
Aid in the proper functioning of muscles and
nerves and in the clotting of blood
Needed for growth and repair of body tissue
Body can absorb minerals directly from the
foods you have eaten.
Calcium and Phosphorus
O The most abundant minerals in the body
O Reserves are stored in the bones
O Also found in teeth, soft tissues, and body fluids.
O Calcium is used to regulate the use of other
minerals in the body
O Without calcium the blood will not clot.
O Calcium also helps the nervous system to
function
O 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 decay
O Not readily available in foods
O Some cities add fluorine to the supply of
drinking water
Iodine
O Iodine is present in very small amounts in the
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body, but it is essential for good health
Iodine is used to make thyroxine
Thyroxine is a hormone produced by the thyroid
gland
Thyroxine controls the rate at which the body
uses nutrients
When the diet is low in iodine, the thyroid gland
enlarges, this condition is called a goiter.
Iron
O Iron is another essential mineral
O 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
Iron
O 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
Zinc
O Zinc has a number of functions in the body:
O It is important for normal growth and
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development
Helps the immune system work properly
Helps wounds heal
Too little zinc in children can stunt growth
An excess can be toxic
Meat, fish poultry, whole grains, and some
legumes are good sources of zinc.
Other minerals
O The body needs a number of other minerals
to maintain good health
O These include copper, potassium, chlorine,
magnesium, and selenium
O 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 A
O Vitamin A is needed for good vision, normal growth
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and healthy skin.
A deficiency of vitamin A can cause night blindness
and drying of the eyes and skin.
Night blindness occurs when the eyes cannot adjust
from bright to dim light
Excesses of vitamin A from food are not common, if
gotten from pill form individuals may experience
fatigue, headaches, and vomiting.
Good sources of vitamin A are liver, whole and
fortified milk products, and fish oils.
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 D
O Extra vitamin D is stored in the body
O 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 E
O The main function of vitamin E in the human
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body is to act as an antioxidant.
This is a substance that protects compounds
from the damaging effects of oxygen
Vitamin E protects blood cells and cells in the
lungs from oxygen damage.
Vitamin E is found in vegetable oils, whole grain
cereals, liver, and green leafy vegetables.
Rarely deficiencies
Vitamin K
O Vitamin K is needed for proper blood clotting
O 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 Vitamins
O 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 vitamins
O The B vitamins and vitamin C are water-
soluble vitamins.
O These vitamins can be lost during cooking
O 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 B
O The B vitamins are a group of vitamins that
are similar
O 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
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you eat
It is important in promoting a normal appetite
and good digestion
Helps the nervous system function properly
A deficiency of thiamin can result in nausea,
depression, loss of appetite, and fatigue.
A severe deficiency can lead to aa disease
called beriberi
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.
Niacin
O Needed to help you obtain energy from
foods
O 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.
Folate
O Used for making all new cells
O 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.
Folate
O 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 nerves
O A vitamin B12 deficiency can result in
anemia and nerve damage
O Naturally occurs only in foods of animal
origin, such as meat, fish, poultry, eggs, and
dairy products.
Vitamin C
O Helps hold body cells together and keeps the
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walls of the blood vessels strong
Important in the healing of wounds, also helps
you body fight infection
A lack of vitaminC over time may result in
bleeding gums, loose teeth, bruising, and sore
joints.
A severe deficiency of vitamin C and lead to a
disease called scurvy.
Sources of vitamin C citrus fruits, strawberries,
cantaloupe, peppers, broccoli, and tomatoes.
Water
O Water is one of the most important nutrients
O Over half of the body’s weight is water
O 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 digestion
O Water regulates body temperature
Water
O You should try to drink six to eight glasses of
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water each day
Get additional water from the foods you eat
Soup, watermelon, tomatoes, and even
breads and meats contain water.
Water is also a product of chemical reaction
that take place in your body
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,
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the Recommended Dietary Allowances were
established in 1941.
From time to time these are revised
These four types of values are jointly called
Dietary Reference Intake(DRI)
Outline nutrient requirements for each sex and
for several age groups
Allowances include needs for energy, protein,
and many vitamins and minerals
Designed to meet the needs of healthy people.
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O 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.
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Department of Agriculture and Health and
Human Services have suggested Dietary
Guidelines for Americans
Aim for a healthy weight
Be physically active each day
Let the pyramid guide your food choices
Choose a variety of grains daily, especially whole
grain
Choose a variety of fruits and vegetables daily
Keep food safe to eat
Dietary Guidelines
O 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
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Nutritional Needs Change
O Identify dietary needs of people in different
stages of life
O Describe special nutrient needs of athletes
Nutritional needs change
O All people need the same nutrients.
O The amounts needed vary from person to
person
O Women need more iron than men
O 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 birth
O 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 Birth
O 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 grain
O Plenty of fruits and vegetables
O Doctors may prescribe nutrient supplements
to help meet increased needs during
pregnancy.
Nutrition in Infancy
O 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 change
O 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 growth
O Meals and snacks for teens need to be
carefully planned
O 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 diet
O This is a pattern of eating that is made up largely
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or entirely of foods from plant sources.
Vegans consume no foods of animal origin
Lactovegetarians exclude meat, poultry, fish,
and eggs but include dairy products
Ovo vegetarians omit meat, poultry, fish, and
dairy products but include eggs.
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 intake
O Drink plenty of fluids
O Eat plenty of iron-rich foods
O Meet daily calcium needs
Needs of adults
O 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 proteins
O Vitamins and minerals, such as Vitamin C,
and zinc
O Some illness may be prescribed a diet by
doctors and registered dieticians.
Section 14-4
O Balancing Calories and Energy Needs
O 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 Needs
O 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 weight
O Weight management involves both eating
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and physical activity.
The foods you eat give your body energy,
To control your weight you need to compare
the calories you eat to the calories you burn
How much should your weight?
Based on body frame bone structure
Healthy Weight Loss
O 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 selfconcept.
Guidelines healthy weight
O Try to maintain a balance between food intake
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and physical activity
Try to spend at least 60 minutes each day in
moderate physical activity
Base your diet on grains, vegetables, and fruits.
Avoid omitting any group of foods from your diet
Avoid making drastic changes in your food intake
without the advice of your doctor
Beware of fad diets that focus on one or two
foods.
Eating disorders
O 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 bingepurge 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 Disorders
O 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.