Chapter 5 Nutrition and Your Health. Lesson 1 Nutrition During the Teen Years.
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Transcript of Chapter 5 Nutrition and Your Health. Lesson 1 Nutrition During the Teen Years.
Chapter 5
Nutrition and Your Health
Lesson 1
Nutrition During the Teen Years
The Importance of Good Nutrition
• Nutrition – The process by which the body takes in and uses
food
• Calories– Units of heat that measure the energy used by the
body and the energy that foods supply to the body
• Nutrients– Substances in food that your body needs to grow, to
repair itself, and to supply you with energy
What Influences Your Food Choices?
• Hunger and Appetite– Hunger: unlearned, inborn response, is a natural physical drive
that protects you from starvation– Stomach walls contract => stimulates nerve endings=> sends
signal to brain=>eat and stomach walls are stretched=>nerve endings are no longer stimulated
• Food and Emotions– Do you eat more or less when you are stressed, frustrated or
depressed?– Snack if you are bored? Do you reward yourself with food?– Using food to relieve tension or boredom or to reward oneself
can result in overeating and unhealthy weight gain
What Influences Your Food Choices?
• Food and Your Environment– Family, friends and peers:
• many eating habits are shaped as people grow up, influenced to try new things
– Cultural and ethnic background– Convenience and cost:
• Busy families may rely on microwaveable foods
– Advertising:• Spend millions of dollars to influence people to eat
certain foods
Lesson 2
Nutrients
Carbohydrates
• Carbohydrates: are the starches and sugars present in foods– Made up of carbon, oxygen and hydrogen – Are the body’s preferred source of energy– Providing 4 calories per gram– Classified as simple or complex– Most nutritionists recommend 55 to 60
percent of your daily calories come from carbohydrates, mainly complex
Carbohydrates cont 1.,
• Simple Carbohydrates– Sugars, such as
fructose and lactose, found in fruit and milk
– Sucrose: sugarcane and sugar beets=>refines to make table sugar
• Complex Carbohydrates– Starches, found in
whole grains, seeds, nuts, legumes (dried peas and beans) and tubers (root veggies such as potatoes)
– The body must break these down into simple carbs before they can be used for energy
Role of Carbohydrates
• Body converts all carbohydrates to glucose, a simple sugar that is the body’s main source of energy
• Glucose that your body does not use right away is stored in the liver and muscles as a starch-like substance called glycogen
• When more energy is needed your body converts the glycogen back to glucose
• However, it is possible to take in more carbohydrates than your body can use right away=>the body converts and stores the excess as body fat
Carbohydrates cont 2.,
• Fiber– An indigestible complex carbohydrate that is
found in the tough, stringy parts of vegetables, fruits and whole grains
– Although it cannot be digested and used as energy, fiber helps move waste through the digestive system
– Fiber helps reduce the risk of heart disease– Examples of Fiber?????
Proteins
• Nutrients that help build and maintain body cells and tissues
• Made of long chains of substances called amino acids
• Your body can manufacture all but 9 of the 20 different amino acids that make up proteins
• The 9 come from the food we eat
Proteins cont 1.,
• Complete Proteins– Contain adequate amounts of all nine essential amino
acids– Animal products such as fish, meat, poultry, eggs,
milk, cheese and yogurt, and many soybean products
• Incomplete Proteins– Lack one or more of the essential amino acids– Beans, peas, nuts and whole grains– Consuming a few incomplete proteins together is
equivalent to consuming a complete protein (over the course of a day, not in one meal)
Proteins cont 2.,
• Role of Proteins– During major growth periods, such as infancy, childhood,
adolescence and pregnancy, the body builds new cells and tissue from amino acids in proteins
– Provides the body with energy (not the main source)– Replaces damaged or worn-out cells by making new ones from
proteins– The body also uses proteins to make enzymes, hormones and
antibodies• Enzymes-substances that control the rate of chemical reactions in
your cells• Hormones-regulate the activities of different cells• Antibodies-help identify and destroy disease-causing organisms
Fats
• Some fats in diets are good for health• Lipid: a fatty substance that does not dissolve in water• Fats provide more than twice the energy of
carbohydrates or proteins• The building blocks of fats are fatty acids, molecules
made mostly of long chains of carbon atoms, with pairs of hydrogen atoms and single oxygen atoms attached
• Essential fatty acids: fatty acids that the body needs, but cannot produce
• Fatty acids are classified as either saturated or unsaturated – most are a mixture of the two
Fats cont.,• Saturated Fatty Acids
– Holds all the hydrogen atoms– Fats high in saturated fatty
acids are usually solid at room temperature
– Animal fats and tropical oils have a a high proportion of saturated fatty acids
– Fats in beef, pork, egg yolks and dairy foods are higher in saturated fatty acids than are the fats in chicken and fish
– Associated with an increased risk of heart disease
• Unsaturated Fatty Acids– Has at least one unsaturated
bond, a place where hydrogen can be added to the molecule
– Usually liquids (oils) at room temperature
– Vegetable fats – olive oil, canola, soybean, corn and cottonseed oils – contain a high proportion of unsaturated fatty acids
– Associated with a reduced risk of heart disease
– Two types: 1.Monounsaturated fatty acids and 2. Polyunsaturated fatty acids
The Role of Fats
• Provide a concentrated form of energy• Transport vitamins A, D, E and K in your blood and serve
as sources of linoleic acid, an essential fatty acid that is needed for growth and healthy skin
• Adds flavor and texture to food• Take longer to digest than carbohydrates and proteins,
so they help satisfy hunger longer• Fats usually contain more calories than other foods so
consuming an excess amount can lead to unhealthy weight gain and obesity
• No more than 20 to 30 percent of your totally daily caloric intake
The Role of Cholesterol• Waxy lipid like substance that circulates in blood• Your body uses the small amount it manufactures to make cell
membranes and nerve tissue and to produce many hormones, vitamin D and bile, which helps digest fats
• Excess blood cholesterol is deposited in arteries, including the arteries of the heart. This increases the risk of heart disease
• High cholesterol may be hereditary• Tend to rise with age• Reduce your risk by eating a diet low in saturated fats and
cholesterol• Dietary cholesterol is found only in animal products such as egg
yolks, meats (organ meats) and high-fat milk products• Losing excess weight can also lower cholesterol levels
Vitamins
• Compounds that help regulate many vital body processes, including digestion, absorption, and metabolism of other nutrients
• Classified as either water or fat soluble– Water-soluble vitamins dissolve in water and pass
easily into the blood during digestion• the body does not store these so you must replenish them
regularly
– Fat-soluble vitamins are absorbed, stored and transported in fat
• Your body stores these in your fatty tissue, liver and kidneys• Excess build-up of these can be toxic
Minerals
Minerals
• Substances that the body cannot manufacture but that are needed for forming healthy bones and teeth and for regulating many vital body processes
Water
• Vital to every body function• Transports other nutrients to and carries wastes from
your cells • Lubricates joints and mucous membranes• Swallow and digest foods, absorb other nutrients and
eliminates wastes• Through perspiration, water helps maintain normal body
temperature• Important to drink at least 8 cups of water each day
– Plain water, milk and juice are the best sources– Caffeine drinks are not good choices – causes increased
urination– Foods, such as fruits and vegetables contain some water
Lesson 3
Guidelines for Healthful
Eating
Dietary Guidelines for Americans
• Set of recommendations for healthful eating and active living
• Grouped into three broad areas known as the ABCs of good health
• The U.S. Department of Agriculture (USDA) and the Department of Health and Human Services (DHHS)
ABCs
• A: Aim for Fitness– Fitness goals: aim for a healthy weight and be
physically active each day
• B: Build a Healthy Base– Healthful eating plan: Food Guide Pyramid – a guide
for making healthful daily food choices– Make your food choices carefully, choose a variety of
grain products, especially whole grains, choose a variety of fruits and vegetables daily and keep food safe to eat
– Understanding serving sizes: portion control
ABCs cont.,
• C: Choose Sensibly– Choosing a diet that is low in saturated fat and
cholesterol and moderate in total fat• No more than 30% of calories should come from fats
– Choosing beverages and foods to moderate your intake of sugars
• Identify added sugars and limit your intake– Choosing and preparing foods with less salt
• Sodium is an essential mineral, helps transport nutrients into your cells and helps move wastes out
• Moderate your salt intake (pg. 126)• Watch out for processed foods• Taste your food before you salt it• Season foods with herbs and spices instead of salt
Healthy Eating Patterns
Variety, Moderation and Balance• The Importance of Eating Breakfast
– Fresh supply of energy, improves mental and physical performances and reduces fatigue later in the day, help maintain a healthy body weight
• Nutritious Snacks– Whole grain products, fruits and vegetables
• Figure 5.6
• Eating Out, Eating Right– For less fat order foods that are grilled, baked or broiled– Ask for sauces on the side or to hold the sauce– Always remember portion control
Lesson 4
Food and Healthy Living
Nutrition Labeling
• The law requires that Nutrition Facts panels be placed on packages of food that are intended for sale
• Most food labels also list the food’s ingredients by weight, in descending order, with the ingredient in the greatest amount listed first
• Food Additives: substances intentionally added to food to produce a desired effect (flavor, color or lengthen its storage life)
• Sugar and Fat Substitutes: aspartame - which is essentially calorie-free (diet sodas), olestra - passes through the body undigested (potato chips)
Product Labeling
• Nutrient Content Claims– Light or Lite– Less– Free– More– High, Rich In, or
Excellent Source Of– Lean
• Open Dating– Expiration date– Freshness date– Pack date– Sell-by date (or pull
date)
Food Sensitivities
• Food Allergy– A condition in which the body’s immune system reacts
to substances in some foods• These substances are called allergens, are proteins that the
body responds to as if they were pathogens, or foreign invaders
• Simple blood test to find an allergy to a food• Reactions can be a rash to vomiting to sneezing
• Food Intolerances– A negative reaction to a food or part of food caused
by a metabolic problem, such as the inability to digest parts of the certain foods or food components
– Hereditary such as lactose intolerant
Foodborne Illness
• Food poisoning• May result from eating food contaminated with
pathogens (disease-causing organisms), the poisons they produce, or poisonous chemicals
• Many times it cannot be seen, smelled or tasted• Protect yourself by becoming knowledgeable
about the causes of such illnesses and ways to keep food safe
Causes and Symptoms of Foodborne Illness
• According to the Centers for Disease Control and Prevention (CDC), bacteria and viruses cause most common foodborne illnesses
• Bacteria that contaminate food include Campylobacter, Salmonella, and E. coli
• Viruses include the Norwalk and Norwalk-like viruses• Food becomes contaminated with these pathogens in
two ways: 1. by an infected person and 2. animals raised or caught might harbor these in their tissues– Pasteurization: the process of treating a substance with heat to
destroy or slow the growth of pathogens
Commons symptoms: nausea, vomiting, diarrhea and fever
Minimizing Risks of Foodborne Illness
• Clean– Cross-contamination: the spreading of bacteria or other pathogens from
one food to another– Wash everything
• Separate– Separate raw meat, fish and poultry from everything else when
shopping and at home store separately from other foods• Cook
– 160 degrees F for ground beef, 170 degrees F for roasts and poultry and 145 degrees F for fish
– When cooked fully the juices should run clearly • Chill
– Cold temperature slow the multiplication of bacteria– Refrigerate or freeze perishable foods – Refrigerate or freeze prepared foods within 2 hours after a meal or even
sooner on a hot day, discard food that has been sitting out longer