Physical Lifestyle & Nutrition Required Unit Science IV 2013 - 2014 SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 2 Adult Learning Program Physical Lifestyle & Nutrition (Science IV) – Required Unit Module Start Date: ______________________________________________ Anticipated Finish Date: _______________________ Actual Finish Date: _______________________ (Goal: finish this module in 2 months) Area To Do Assignment 1 Date Completed Assignment 2 Assignment 3 Assignments Assignment 4 Assignment 5 Assignment 6 Activity 1 Activity 2 Activities Activity 3 Activity 4 Labs Lab 1: Lung Capacity Projects Project 1: Healthy Lifestyle Project 2: Diet Analysis Test (from assignment questions) Update your tracking card. Keeping on track is the key to success! SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 3 Table of Contents Introduction .............................................................................................................................. 5 Stress - What is it? ................................................................................................................... 8 Cardiovascular System ..........................................................................................................12 Blood Pressure .......................................................................................................................13 The Respiratory System .........................................................................................................13 Fitness and Health ..................................................................................................................15 Pulse Rate ...............................................................................................................................17 The Benefits of Exercise ........................................................................................................17 Training Heart Rate .................................................................................................................18 Active Living ...........................................................................................................................19 Nutrition ...................................................................................................................................20 Canada’s Food Guide to Healthy Living ................................................................................20 The Human Body and Energy ................................................................................................21 Estimating Daily Energy Use at Various Levels of Physical Activity ..................................24 Introducing the Nutrients .......................................................................................................25 Water........................................................................................................................................25 Carbohydrates.........................................................................................................................25 Proteins ...................................................................................................................................26 Fats ..........................................................................................................................................27 Cholesterol: .............................................................................................................................28 The Micronutrients- Vitamins and Minerals ..........................................................................29 Diet and Disease .....................................................................................................................30 Nutrition and Food Labeling ..................................................................................................30 The Use of Food Additives .....................................................................................................32 Nutrients ..................................................................................................................................33 Preservatives...........................................................................................................................33 Processing Aids ......................................................................................................................34 Flavorings................................................................................................................................34 Colourings ...............................................................................................................................34 Dietary Supplements ..............................................................................................................35 Caffeine Drinks .......................................................................................................................36 Weight Loss Diets ...................................................................................................................38 Diverse Diets That Nourish The World ..................................................................................40 SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 4 Introduction In the first section of this module you will be studying the physical component of a healthy lifestyle and in the second section you will be learning about how nutrition relates to living a healthier life. You will be studying stress, and how it can negatively affect your body. You will be learning about the importance of your heart and lungs, and how to keep them working most effectively through active living. The goal of this module is to help you make some discoveries about keeping your body healthy and implementing some of these strategies into your own life. Your assessment pieces will be composed of a number of assignments and activities, a lab, two projects and a test. Most of the resource material is provided in this module, but you will have to obtain some from your instructor and you will have to do some research on your own. What do we mean by “healthy”? The term, “healthy”, as we are going to study it, refers to a mind, body and soul connection in order to be the most productive we can be for ourselves, our families, and society at large. The concept of being healthy is mixed into different facets of our life. It includes physical well-being, which can be brought about by a healthy diet and exercise; it constitutes the maintenance of health through proper precaution and cures for physical ailments. Two often ignored facets of being healthy are mental and spiritual health. What does this mean? It means that we cannot be truly healthy or fully productive if we just have physical health. Without nutritional, emotional, mental or social health we are being less than we are capable of being. Human beings are the most important assets of a nation. It is people who drive the world; it is we who make the world go round. The absence of health can make the world come to a standstill. Imagine if you are physically fit, but recently went through a divorce. Even though you are physically fit, the divorce will affect your daily life, manifesting in the form of worry, loneliness and many more stresses that come along with it. How will your ability to perform your job be affected? As a part of society, every human being has a set of duties to perform. Each person has certain family responsibilities as well as some responsibilities to society. For an individual to be able to take care of these responsibilities, it is important for him/her to be healthy. To maximize your academic performance you need to be healthy. To make progress in a society, to work towards the betterment of society, and to contribute to the overall social welfare, it is extremely important to be healthy. To raise a family, to bring up your children, to take care of the aged, you need to be healthy. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 5 What components of health will we concentrate on in this unit? Physical and nutritional health. By exploring the physical and nutritional components, we will see how other components (mental, social, and emotional) are heavily reliant on them. Health and happiness go hand in hand. To live life to the fullest and enjoy every bit of it, it is extremely important for us to be healthy! What exactly is a healthy lifestyle? It seems experts are constantly telling us what we should eat, how much to exercise, bad habits to cut back on, how much sunlight to get, what vitamins to take, and on and on until we feel it's impossible to live up to those lofty standards. We decide that it doesn't really matter how we lead our lives, and cite examples like our great-uncle who smoked like a chimney and ate nothing but bacon and was still hitting the ski slopes at the ripe old age of 98. Despite the occasional blatant exception, however, we cannot deny the harsh truth: the lifestyle we choose to lead has a huge impact not only on our physical health, but also on our mental well-being and overall sense of happiness. We can change nasty habits, and when we finally find the courage to make those difficult changes, we feel so much better. We quit smoking and breathe more easily and start jogging again; we cut greasy foods out of our diets and we're less sluggish; we get more sleep and feel on the ball at work and at school. In the end, the changes that seemed so painful and nearly impossible become such a major part of our lives that we can't imagine how we could have lived the old way. We never regret those healthy transformations. So how do you get off on the right foot and make the decisions that can lead to a healthier and happier lifestyle? First, educate yourself; find out what your body needs to operate smoothly. The next step is to evaluate how your body is doing. Finally, the most challenging but also most satisfying part: you must make real plans to incorporate any necessary changes. As Oprah Winfrey has said, "Getting my lifelong weight struggle under control has come from a process of treating myself as well as I treat others in every way." Simply put, to be healthy, we need to make ourselves a priority and be kind to ourselves. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 6 The Six Dimensions of Health Health is complex and involves the interaction of varying factors. In 1948, the World Health Organization (WHO) wanted criteria to measure the “functionality” of an individual. The first three identified criteria include the physical, the social, and the mental constructs. Later, the emotional, spiritual, and environmental dimensions are added to the list. Here is a list of the six dimensions of health and brief descriptions as found on the website http://www.sa.usf.edu/wellness/about/wheel.htm Physical - The physical dimension recognizes the need for regular physical activity. Physical development encourages learning about diet and nutrition while discouraging the use of tobacco, drugs and excessive alcohol consumption. Optimal wellness is met through the combination of good exercise and eating habits. Social - The social dimension encourages contributing to one’s environment and community. It emphasizes the interdependence between others and nature. Intellectual - Measures the degree to which one engages in creative, stimulating mental activities. An intellectually healthy person uses the resources available to expand his/her knowledge and to improve skills, along with expanding the potential for sharing with others. Benefits include improved job performance, better problem solving, more knowledge and a better chance at being successful in life. Occupational - measures the satisfaction gained from one's work and the degree to which one is enriched by the work. The satisfaction gained is related to individual attitudes about work, a sense of direction and goals, and a feeling of achievement. This work may be paid work or it may be the work of being a parent or a volunteer. Emotional - The emotional dimension recognizes awareness and acceptance of one's feelings. Emotional wellness includes the degree to which one feels positive and enthusiastic about oneself and life. It includes the capacity to manage one's feelings and related behaviours including the realistic assessment of one's limitations, development of autonomy, and ability to cope effectively with stress. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 7 Spiritual - The spiritual dimension recognizes our search for meaning and purpose in human existence. It includes the development of a deep appreciation for the depth and expanse of life and natural forces that exist in the universe. Your search will be characterized by a peaceful harmony between internal personal feelings and emotions and the rough and rugged stretches of your path. These may be summarized as given below. 1. Physical the ability of human body structure to function properly 2. Social the ability to interact with other individuals 3. Mental/intellectual the ability to process information and act properly 4. Emotional the ability to cope, adjust, and adapt 5. Spiritual the belief in some force or dynamic other than human 6. Occupational the ability to find rewarding work and financial resources You may visit the website http://www.sa.usf.edu/wellness/about/wheel.htm to learn more about the different dimensions of health. Stress - What is it? One definition of stress is “a physical, chemical, or emotional factor that causes bodily or mental tension, and that may be a factor in disease causation”. There are two components to stress. The stressor (the trigger that causes you to be stressed) and the reaction (the response you have to the trigger – conscious and subconscious). There are many factors that can cause stress. They could be physical or chemical such as trauma, illness or infection, or they could be emotional. Any sort of force that impairs the stability and balance of bodily functions is considered stress. Stress is part of life, but has come to have a negative connotation associated with it. There is “good stress” and “bad stress”. Feeling mildly stressed when carrying out a project or assignment often compels us to do a good job and work energetically. Also, exercising can place a temporary stress on some body functions (the heart has to pump harder), but its health benefits overcome any negative effects. Getting married, being promoted at work, or moving to a new home may not be perceived as being threatening; however, they can be seen as stressful because of the response they evoke from our bodies. It is only when stress is overwhelming, or poorly managed, that its negative effects appear. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 8 “Stress” is a word that is commonly used, but many people are not clear what it is really about. Many people consider stress to be something that happens to them, an event such as an injury or a mishap. Others think that stress is what happens to our bodies, our minds, and our behaviours in response to an event, such as a pounding heart, anxiety, or nail biting. While stress does involve events and our response to them, these are not the most important factors. Our thoughts about the situations in which we find ourselves are the critical factors to dealing effectively with stress. Reacting to Stress When something happens to us, we automatically evaluate the situation mentally. If it is threatening to us, we decide how we need to deal with it and what skills we can use. If the demands of the situation outweigh the skills we have, then we label the situation as “stressful”, and react with the “classic stress response”. If we decide that our coping skills outweigh the demands of the situation, then we don’t see it as “stressful”. Everyone sees a situation differently, and each person has different coping skills. For this reason, no two people will respond exactly the same to a given situation. The degree of stress we perceive in our lives is highly dependent on individual factors such as physical health, the quality of our interpersonal relationships, the number of commitments and responsibilities we have, the degree of others’ dependence upon us and others’ expectations of us, the amount of support we receive from others, and the number of traumatic events that have recently occurred in our lives. Some generalizations can be made. People with enough social support networks report having less stress and overall improved mental health when compared to those without these social contacts. People who are poorly nourished, who do not get adequate sleep, or who are unwell physically also have reduced abilities to handle the stresses and pressures of everyday life. If we decide that a situation is stressful, our body’s “fight or flight” reaction activates, causing the release of adrenalin, a natural body chemical. This is the first stage of the stress response. A number of short-term physical symptoms can occur as your body adapts to perceived physical threat. These symptoms are caused by adrenalin release. Although they may be perceived as unpleasant and negative, they are signs that your body is ready for the explosive action that assists survival or high performance. Effects of Stress Short-term effects. Some symptoms you might immediately experience are faster heartbeat, increased sweating, cool skin, cold hands and feet, feelings of nausea or “butterflies in your stomach”, rapid breathing, dry mouth, or diarrhea. While adrenalin helps you survive in a “fight or flight” situation, it does have negative effects. One of the ways that adrenalin prepares you for action is by diverting food SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 9 and oxygen to the muscles instead of other organs. It interferes with clear judgment, it interferes with fine motor control, it promotes negative thinking, damages self-confidence, and it disrupts concentration, and causes anxiety, frustration and temper. If your body has been exposed to adrenalin over a long period of time, there are some long-term physical symptoms that can occur. This means that if you are under constant stress, and therefore adrenalin is in your circulation, other parts of your body can start to suffer. Long-term effects. This may show up in a variety of ways. Some people report that stress induces headaches, sleep disturbances, feelings of anxiety, anger or concentration problems. Others complain of depression, loss of appetite, increased appetite, and muscle tension, crying outbursts or increased use of drugs or alcohol. It has been proven through research that high levels of stress are known to exert a negative influence of our immune system, and stressed individuals can experience more frequent illness. Stressed people may, over time develop higher blood cholesterol, and raised blood pressure. In severe situations one can experience stress to the point of so called “burnout”, with loss of interest in normal activities. How to Deal with Stress Knowing what YOU do when you are under stress is the first step in responding to stress. To cope with stress, you need to know when it is happening. The signs of stress listed above can give you clues you can use to change your response to stress. The next time you feel you are getting stressed, take time to check your body, your emotions, and your behaviour. If you recognize some of your usual signs of stress, then you know that you need to try some coping strategies. It is one’s attitude toward the stressors, major and minor that counts. We may be motivated and invigorated by the events in our lives, or we may see them as “stressful” and respond in a manner that may have a negative effect on our physical, mental, and social well-being. If we always respond in a negative way, our health and happiness may suffer. By understanding ourselves, and our reaction to stress provoking situations, we can learn to handle stress more effectively. It is impossible to completely eliminate stress, and it would not be advisable to do so. Instead we can learn to manage stress so that we can have control over our stress and its effects on our physical and mental health. Throughout the year the Learning Centre offers a variety of workshops on stress and coping strategies to use. Be sure to check out these as well as other Learning Centre workshops. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 10 Sleep essential to healthy lifestyle Carol Wagner-Adams* Sleep is one of the most understated aspects of wellness. Research empirically demonstrates how critical sound and regular sleep is to health, mental alertness, and staying even-tempered. Dr. William Dement has shown in his research that when one’s body does not get the needed seven to eight hours of sleep per night, the body registers a sleep debt. Accumulated debt increases the probability of daytime sleepiness, lowered productivity, a tendency to be angry or violent, injuries and premature death. College and university students are known for their inconsistent sleep patterns. “Burning the midnight oil” one night and sleeping for 14 hours the next day plays havoc with one’s circadian (sleep-wake) rhythms. It is not possible to erase one’s sleep debt by extending the next night’s sleep. Some recent research from the University of Chicago has demonstrated that long-term sleep debt may lead to serious conditions that compromise one’s health such as obesity, diabetes and high blood pressure. Even in young, healthy individuals, the Chicago researchers found evidence that sleep debt accumulated over a week compromised metabolic and endocrine functioning. Inadequate sleep also altered cognitive functioning, such as memory, critical thinking, and mental alertness – all important to being a successful student. Immune systems also were adversely affected. Helpful tips for getting yourself on a routine of good sleep include: Establishing a sleep routine with the same time daily for going to bed and getting up in the morning. Sleeping in a room that is cool, dark, and quiet. Using a white noise box or a relaxation tape to help you sleep if noises disturb you Avoiding stimulants such as coffee, soft drinks and other caffeine drinks several hours before sleep Doing a relaxing, quiet activity such as reading, bathing or listening to soothing music shortly before going to bed. Set aside a brief amount of time to worry daily, and when the time is up, stop worrying and go on with your daily tasks. Good sleep, just like a good diet, regular exercise, and supportive friends and family, is an essential ingredient to a healthy lifestyle. *Carol Wagner-Adams received her bachelor’s degree from State University of New York at Oswego, master’s degree from Ohio University and doctorate from Indiana State University. She is a licensed psychologist and the manager of Counseling and Therapy Services at the Student Health Center. Complete Assignment 1 SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 11 Cardiovascular System The next aspect of healthy living to be explored is “cardiovascular fitness”. “Cardio” refers to the heart and “vascular” has to do with the flow of blood through the circulatory vessels. Good cardiovascular health means that the heart is pumping efficiently, and the vessels that connect to it are circulating the blood to the body’s cells effectively. This flow can be affected when there is a build-up of cholesterol and fatty acids along the walls of the arteries. If untreated, this build-up can lead to events such as heart attacks and strokes. Keeping your cardiovascular system in good condition is very important for good health. Exercising aerobically (when your heart beats faster and you breathe faster and deeper) is necessary for maximizing your cardiovascular health. When your cardiovascular system is working efficiently you are able to take in oxygen and get rid of carbon dioxide effectively. Your heart pumps your blood to all parts of your body without discomfort or pain. The Human Heart and Major Blood Vessels Blood enters the heart from the upper body through the superior vena cava and from the lower body through the inferior vena cava. The chamber receiving this blood is the right atrium. Blood will then pass through the tricuspid valve into the right ventricle. When the muscular right ventricle contracts it sends blood out through the pulmonary valve into the pulmonary arteries and to the lungs. Next the blood returns from the lungs via the pulmonary veins into the left atrium. From here the blood passes through the mitral valve into the left ventricle. When the left ventricle contracts, blood is pushed out through the aorta, the largest blood vessel in the body, to all body parts. The aorta has many arteries (blood vessels leading away from the heart) that branch from it. The superior and inferior vena cavas are the largest veins (blood vessels that bring blood into the heart) in the body. Connecting the arteries and the veins are many tiny microscopic blood vessels known as capillaries. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 12 Blood Pressure Blood pressure is a measure of the pressure your blood exerts on the walls of your blood vessels as it flows through them. It is measured in mm of mercury, meaning how many millimetres of mercury in a tube of a certain diameter could the pressure push up. There are two numbers in a blood pressure reading. The top number is the systolic number and represents the pressure or force on the blood generated when the ventricles of the heart contract. The bottom number is the diastolic number and represents the pressure or force on the blood generated when the ventricles of the heart are relaxed. Our blood pressure fluctuates throughout the day and from day to day depending on the events we are dealing with or the activities we are participating in or our general state of health. This is why it is important to measure your blood pressure on different days and at different times to get an average reading of your blood pressure value. According to the Canadian Heart and stroke foundation Blood pressure that is consistently more than 140 / 90 mm Hg is considered high, but if you have diabetes, 130 / 80 mm Hg is high. Normal blood pressure is below 120 / 80 mm Hg. Complete Assignment 2 The Respiratory System The process by which the body exchanges oxygen and carbon dioxide with its environment is called respiration. Our bodies are taking in oxygen, needed to burn the food we eat as fuel, and releasing carbon dioxide to the environment. Carbon dioxide is produced as a waste produce when our bodies use the food we consume. Our lungs and the system of tubes connecting to them, allow air to enter so that oxygen can be extracted for our use. In this section, you will study the parts of the respiratory system and their major functions. You will also measure the amount of air your lungs can hold by conducting a lab on “lung capacity” to determine the fitness of your lungs. When we breathe in, or inhale, the muscles between our ribs contract and lift our rib cage up and out. Our diaphragms (a large muscle just below our rib cage) also contracts and straightens. This creates more room in our abdomen cavity and air is sucked into our lungs. When we exhale, our rib muscles relax and fall back into their resting place and our diaphragm also relaxes. When the diaphragm relaxes is curves upward pushing against the lungs and thus pushing air out of the lungs. There is usually dust, dirt, microorganisms, and other pollutants in the air we breathe. The respiratory tract (tubes) is lined with tiny microscopic hairs (cilia) and mucus. Much of the particulate matter in the air is trapped in the mucus and by moving back and forth, the cilia help to sweep it upward and out of our bodies. Coughing and spit enable us to expel this mucus from our respiratory tract. This is one reason during pollen season we often have to cough and spit much more than at other times in the year. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 13 The respiratory system has a number of structures. Air will first pass into the nasal and oral cavities (if your mouth is open). Next it passes through the area where the nasal and oral cavities meet known as the pharynx. When we breathe a flap of cartilage, known as the epiglottis lifts to open the trachea or windpipe so that air may enter this tube. When you are eating and something “goes down the wrong way” the food has entered your trachea and has triggered a coughing reflex. This most often occurs because of people talking while chewing. The trachea has rings of tough tissue known as cartilage to keep it open. At the top of the trachea is another structure known as the larynx (Adam’s Apple), containing the vocal chords. Next air passes into the two bronchi tubes, one leading into each lung. These are the tubes that get infected and inflamed when you have bronchitis. Each bronchus divides into smaller bronchial tubes known as bronchioles. At the ends of each bronchiole are air sacs that look like bunches of grapes or bubbles. These air sacs are alveoli (alveolus); the site of gas exchange. Assignment 3 will help you review this material presented in this section of this module. The lab is required unless you have a respiratory or heart condition and your physician has advised you not to partake in strenuous activities. Please advise your instructor if this is your situation. Please note you may be required to provide a doctor’s note to document your exemption. Complete Lung Capacity Lab SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 14 Fitness and Health There is almost universal agreement that optimum health is our most prized possession. To improve, or even maintain our health, it is important for people of all ages to participate in physical exercise. Before we explore exercise, it is first important to know what “physical fitness” is. The simplest, most practical definition of physical fitness is the ability to respond to routine physical demands, with enough reserve energy to cope with a sudden challenge. You can consider yourself fit if you meet daily energy needs, can handle unexpected extra demands, have a realistic but positive self-image, and are protecting yourself against potential health problems. Basic Components of Physical Fitness The four basic components of physical fitness are cardio-respiratory endurance, muscle strength or endurance, flexibility, and body composition. Below is a general description of what each component means and examples of how to assess each component. 1. Cardio-respiratory endurance activities refer to continuous activities that encourage the heart to pump blood through your body efficiently. Good cardio-respiratory endurance is achieved through aerobic exercise - any activity such as brisk walking, or swimming, in which the amount of oxygen used by the body is slightly more than the normal amount of oxygen used by the body. This causes our heart and lungs to work harder than normal to deliver oxygen to all of the body’s cells. Activities that fit into this category burn fat and build muscles at the same time. Cardio-respiratory endurance assessments: Stress Test 1.5-mile run test 1-mile walk test 3-mile bike test 500-yd swim test 3-minute step test 2. Flexibility is the range of motion around specific joints, such as your ability to reach down and touch your toes. Flexibility depends on a number of factors such as your age, sex, posture, and body size. As children develop, their flexibility is increased until adolescence, and then a gradual loss of joint mobility can occur. Both muscles and connective tissue can shorten and tighten if not used through their full range of motion. Stretching exercises can help prevent loss of flexibility, but should only be done AFTER the body’s muscles have warmed up. NEVER perform static (stationary, developmental) stretch prior to working out. When stretching, hold the position for a minimum of 20 – 30 seconds; do not bounce as this can cause damage. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 15 Flexibility Assessments Lower back flexibility Hip flexor flexibility test Quadriceps flexibility test Sit and reach test Sit and reach wall test 3. Muscular strength refers to the body’s ability to do activities against resistance to strengthen muscles and improve posture. There are a variety of ways to strengthen your muscles. Some people use weight machines, others use free weights, others use resistance bands, and others use their body weight as resistance. Muscular Strength and Endurance Assessments Abdominal curl test Push up test Leg press strength test Bench press strength test 4. Body composition is the proportion of body fat compared to bone and muscle mass. Improving body composition increases your metabolism and energy level. Aerobic exercise and activities like brisk walking, jogging, swimming, cycling and stretching along with good nutrition will decrease body fat and increase or maintain muscle mass. Body composition Assessments BMI Hip-to-Waist Ratio Hydrostatic weighing Skin fold test To achieve physical fitness, professionals recommend a regular exercise program that includes aerobic exercises for the cardiovascular system (heart and lungs), and strength training exercises for the muscles. Canada’s Physical Activity Guide recommends, for adults 18 years of age – 64 years of age, a minimum of 150 minutes (in bouts not shorter than 10 mintues) of gentle physical activity per week to stay healthy or improve your health. For those who participate in sports and would like more of a challenge, 20 – 60 minutes of aerobic exercise three to five times each week, plus two to three strength workouts each week, promotes optimal fitness. Canada’s Physical Activity Guide can be accessed through http://www.csep.ca/CMFiles/Guidelines/CSEP_Guidelines_Handbook.pdf . SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 16 Pulse Rate Pulse is a good indicator of how your circulatory system, especially your heart, is working. The pumping of your heart is caused by the alternating contraction and relaxation of your heart (cardiac) muscle. Each contraction is one heartbeat. During your lifetime the heart will contract and relax millions of times. The normal heart rate (pulse rate) for an adult is between 60 and 80 beats per minute. Age, sex, physical condition, and physical activity affect this rate. Babies have a heart rate of about 130 beats per minute. You were born with approximately the same number of heart muscle cells as you have today. As you have grown the number has stayed the same, but the size of the cells have changed. An increase in the size of any muscle cell is the result of exercise. The more exercise you do, the larger the muscle cells, and the stronger your heart will be. Since a stronger heart can pump more blood, fewer beats are needed per minute to circulate your blood around the body. Well-trained athletes have a very low resting heart rate (about 55 beats per minute) compared to the average person (about 72 beats per minute). Practice taking your heart rate. What is your resting heart rate while sitting? _______________ What is your heart rate after standing for a couple of minutes? ____________ What is your heart rate after quickly walking up a flight of stairs? _______________ The Benefits of Exercise As we know, exercise is very good for our bodies. You will already know some reasons why it is important to have good health. List five reasons below: 1. _____________________________________________________________ 2._____________________________________________________________ 3._____________________________________________________________ 4. _____________________________________________________________ 5.______________________________________________________________ SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 17 Training Heart Rate As you have learned already, one of the most important reasons to keep fit is to create and maintain a strong and healthy heart. If you are committed to heart health and fitness, it is important to know how to measure the exercise your heart is getting. This is easy and quick. In order to strengthen your heart, you have to work it hard enough to increase its muscle mass, and its ability to do aerobic work. The way to do this is to push your heart to its “training heart rate”. A person’s training heart rate is actually a range between 60% and 80 % of that person’s maximum capacity. Only when very fit and only for short intervals of time should you ever exercise above 80% of your maximum heart rate. This level of intensity is not required to benefit from physical activity and it can be dangerous if training at this level for too long or too soon in your training plan. To calculate your training heart rate, subtract your age in years from 220: 220 - _______ = ______________ beats per minute (Your Age) (Maximum Rate) Take 60% of this number: ________________________ X 0.6 = ____________ beats per minute This number is your minimum training heart rate, or the minimum number of beats your heart needs to perform in one minute to gain any benefits. If you want to train more vigorously, increase the rate to 70%. Training above 80% could be very dangerous to your health by putting extreme stress on your heart, especially in the early stages of beginning a fitness training program.!! 80% of my maximum heart rate is: __________________ X 0.8 = _______________ beats per minute The simplest way to measure your heart rate is to count your pulse for 10 seconds and then multiply by 6. It is easy to do as you exercise, and you can quickly check to see if you are working your heart too much, or not enough. Summary My training heart rate should be ___________________ beats per minute. To know what a good rate for 10 seconds is, I can divide this by 6 to get _________________. This is how many times my heart should safely beat in 10 seconds to show that I am getting exercise. I should never allow my heart rate to go above 80% of my maximum heart rate, or ___________ beats per minute. If I divide this by 6 I get ___________ beats in 10 seconds. Therefore I will remember when exercising that if it reaches this level I am working my heart much too hard. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 18 Active Living What does “Active Living” mean to you? Take a minute and write your personal definition based on what you’ve learned so far. In Canada today, many of us are interested in improving the quality of our lives. We are becoming more aware of how what we do, what we eat, and how our lifestyle affects our health. In former times we thought of physical fitness as a way to improve our health. Today we know that physical activity improves many aspects of our lives. Active Living is based on the belief that physical activity promotes individual well-being, and the quality of life in our families and communities. Active living can be many different things. It could be playing with children, walking the dog, dancing, taking a yoga class, or going for a bike ride with a friend. It also involves more organized activities such as competing in your favourite sport. The idea behind active living is that you make the rules based on what being physically active means in your daily life. Active living should include a variety of activities that help you to improve all aspects of being healthy. These activities will improve your physical fitness: strength, flexibility, and stamina. The activities will also help you improve the mental, spiritual and community aspects of your well-being. Complete Assignment 3 Begin Project 1 SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 19 Nutrition Introduction We know that good nutrition is an important part of being healthy. No matter what you do, you need good health to be able to enjoy life. Food supplies your body with energy and nutrients to keep you in good health. The food you eat and the science of how your body turns it into energy is called nutrition. Good nutrition can improve health. It can contribute to weight control, energy, healthy appearance, and dental health. This module is intended to help you learn more about good nutrition, and how it can affect your life. You will accomplish this by studying a variety of factors related to good nutrition. In this module you will learn about what healthy eating entails. You will analyze your own diet to see if there are any healthy changes that you may wish / need to make. You will learn how to design a healthy menu, how to read labels properly, learn about foods around the world, and more. Good luck, and here’s to healthy eating! Canada’s Food Guide to Healthy Living Nutrition has long been recognized as a key factor in promoting health and preventing disease. Hippocrates, an early Greek physician who is referred to as the “father of modern medicine” believed that good diet was an important part of the recovery period following illness and disease. Accurate knowledge about diet has taken many years of research. In the mid-1800s, a German Chemist, Baron Justus von Liebig proved that three classes of food are needed by the body: carbohydrates, fats and proteins. More recent research has proven that other substances are also needed in smaller quantities, (complex compounds called vitamins, and elemental minerals) for a complete and balanced diet. The Canadian government has recognized the importance of good nutrition and its relationship to good health. One of its federal departments, Health and Welfare Canada, is working to provide Canadians with the information they need to maintain health and reduce the risk of nutrition related diseases. Nutritional guidelines and recommendations, such as Canada’s Food Guide, are familiar to many people. This food guide has been updated in recent years as scientists have learned more about the importance of carbohydrates and whole grain foods in our diets. Today’s Food Guide is based on a set of nutritional recommendations set forth by our federal government. You can find Canada’s Food Guide at http://www.hc-sc.gc.ca/fn-an/food-guide-aliment/index-eng.php or by simply doing a Google search of Canada Food Guide. These recommendations can be summarized by five key statements: 1. Enjoy a variety of foods 2. Emphasize vegetables and fruits, followed by whole grains in your diet. 3. Choose lower fat dairy, leaner meats, and foods prepared with little or no fat. 4. Achieve and maintain a healthy body weight by enjoying regular physical activity and healthy eating. 5. Limit your intake of salt, alcohol, and caffeine. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 20 These recommendations together with what is already known about what the body requires for good nutrition provide the framework for Canada’s Food Guide. Canada’s current food guide incorporates the fact that your sex and your age also affect your dietary requirements. You will notice that the number of servings for each food group reflect this difference in serving requirements. Canada’s Food Guide focuses on fruits and vegetables and grain products. This is founded in the fact that these two food groups are the best supplies of carbohydrates - our bodies’ main fuel source and fibre (an important dietary requirement). Research has also shown the connection between heart disease and increased amounts of salt, fat and caffeine in the diet. We also know that alcohol consumption can interfere with the body’s ability to absorb nutrients, and can raise blood pressure. This information has all been considered in designing our newest food guide. Its four groups provide us with all of the nutrients we need to be healthy, if properly followed. The Human Body and Energy What Is Energy? Energy needs are one of the requirements important in nutrition. Energy is the ability to do work. The human body needs energy because it has work to do. The body obtains chemical energy through the food that it takes in. This food comes either directly or indirectly from plants. This energy is contained in molecules of carbohydrates, protein, or fat. This energy is used in a variety of ways such as promoting the activity of vital organs, maintaining body temperature, promoting growth and repair of body tissues, and performing work, activity, and exercise. How Is This Energy Measured? Energy used by the body is measured in calories. The amount of energy that food supplies is also measured in calories. Although all three food types contain calories, each type of food (carbohydrates, proteins, and fats) provide a different number of calories per gram. Carbohydrates and proteins provide 4 Calories per gram while fat provides 9 Calories per gram. High calorie foods give your body more energy than low calorie foods. Some foods give you lots of calories, but little in the way of nutrients. These are often called “empty calories”. Examples of foods or beverages in this category include chocolate bars, soft drinks, alcohol, and sweets. Canada’s Food Guide identifies these types of food as “other”. How Do You Know How Many Calories Are In The Food That You Eat? Charts are available to provide us with this information, but how do scientists know this? They actually had to burn these foods in specially made containers called calorimeters. Calorimeters burn food in an insulated environment and measure the amount of energy released. This is done, by putting water inside the calorimeter, and measuring how many degrees it rises as the food item is burned. The SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 21 scientific definition of a Calorie is the amount of heat required to raise the temperature of 1 kilogram of water 1 degree Celsius. It is important to distinguish Calorie from calorie. A Calorie is equal to 1000 calories. Energy is often measured in joules. One kilocalorie (the same as a Calorie) is the same as 4.2 kilojoules (kJ). Here are a few samples for you to see how foods compare: Food Apple Apple Pie Beef Stew Celery Hamburger Bun Milk, Non-fat Butter Serving Size 1 medium apple 1 slice 1 cup 1 stalk 1 1 cup 1 Tablespoon Calories 80 400 220 6 120 90 100 Why Should You Be Interested In The Caloric Value Of Foods? One reason is that it helps us to know whether or not the proportion of the food we eat is healthy. A general rule for healthy eating is that no more than 30% of our calories should come from fats. About 50- 60% of our energy should come from carbohydrates, and 20 - 30% from proteins. Mark this section so that you can find these numbers later when you analyze a given diet to determine if it is adequate and healthy. Another reason to check your caloric consumption is to determine whether you are getting enough, too much, or just the right amount of calories for your body’s needs. Generally you can tell by your weight gain or loss. If you are maintaining your weight, you are probably taking in the correct amount of calories. How Do You Know How Many Calories You Should Be Consuming? To do this you need to calculate your basal metabolic rate. Basal metabolic rate (BMR) is the rate at which the body uses energy, to perform essential internal work, such as maintaining the body temperature, breathing, and keeping the heart beating. By knowing how many calories your body need to burn to perform your life’s activities, you will know how many calories you need to consume to keep your body supplied with enough energy. The BMR can be calculated scientifically, but there are several methods that can be used to make an accurate guess at what your needs are. You will try two methods, and see how they compare with each other so you will have an idea whether or not you are consuming the proper number of calories each day. On the next three pages are two methods for calculating a person’s BMR. After examining the examples, calculate your own BMR. If you have trouble understanding the sample calculations or unsure of which values to use for your own calculation, ask your instructor for help. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 22 BMR Calculation: Method 1 Step 1 - Convert you weight to kg: ____________lb divided by 2.2 lb/kg = ____________ (your weight in kilograms) Now refer to the table below, and multiply your weight in kilograms by the numbers provided, then add the number of kilograms the chart gives: Equations for Estimating BMR from Body Weight Sex and Age Range Males: 10 - 18 18 - 30 30 - 60 60+ Females: 10 - 18 18 - 30 30 - 60 60+ Equation to Derive BMR in Cal/day (17.5 X wt.) + 651 (15.3 X wt.) + 679 (11.6 X wt.) + 879 (13.5 X wt.) + 487 (12.2 X wt) + 746 (14.7 X wt) + 496 ( 8.7 X wt) + 829 (10.5 X wt) + 596 Let’s try an example: If you are a 20 year old male and you weigh 160 lb, you would first convert your weight to kilograms: 1. 160 lb divided by 2.2 lb/kg = 72.7 kg (can be rounded to 73) Now, checking the chart, he would use this formula: 2. (15.3 X 72.7 kg) + 679 = 1791 cal/day Now try yours: ___________________ (Your weight in kg as determined above) From the equation for your sex and age: ( ________ X __________kg) + ____________ = ____________ cal/day This is your BMR, or how much energy you use to fuel your body’s basic functions. Now you need to determine how much additional energy you need by considering the amount of physical activity you do. Multiply a number from the chart on the next page by your BMR. To estimate the energy you use for your activities, consult the chart on the next page and determine which type of activity describes the way you spend most of your time. Then multiply the selected activity factor by your BMR (just calculated above). SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 23 Estimating Daily Energy Use at Various Levels of Physical Activity Level of Intensity Typical Types of Activities Very Light Seated and standing work, painting, driving, lab work, typing, cooking Light walking, garage work, electrical trades, carpentry, housecleaning, childcare, golf Light Moderate Activity Factor Energy Expenditure Factor M – 1.3 31 F – 1.3 30 M – 1.6 38 F – 1.5 35 M – 1.7 41 F – 1.6 37 M -2.1 50 F – 1.9 44 Walking 2-3 km/hr, gardening, cycling, downhill skiing, dancing, etc. Walking uphill with a load, walking 4+ km/hr, heavy manual labour, basketball, soccer, football Heavy Use the 20 year old male from above. Assume he is a student at the Nova Scotia Community College who works out at the gym 3 times a week. He would most likely choose 1.7 as his Activity Factor. His daily total energy needs would be: 1.7 X 1791 = 3046 calories per day (rounded to the nearest whole number) (activity factor) X BMR = Calories needed per day What is yours? __________ X __________ = ___________ calories needed each day (Your BMR) (Your Activity Factor) BMR Calculation: Method 2 Now use another method to calculate your daily energy need. In this method we will use your weight and multiply it by your energy expenditure factor, using the values from the last column of the table above. Practice by using our 20 year old male, assuming again that his level of intensity is light. This time you will use the factor in the Energy Expenditure Factor column of the table above. 3. 73 kg X 41 cal/kg/day = 2993 cal/day (weight in kg) X energy expenditure factor) His numbers are 3046, and 2993 which are very close (a difference of only 53 Calories). The difference is insignificant, and the results tell us that he would need about 3025 calories (the average of the two estimates) each day to meet his body’s basic functions and to fuel his body for the other activities he does. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 24 Now try yours, _________ kg X __________ cal/kg/day = ________ cal /day (weight in kg) X (energy expenditure factor) How do your two numbers compare? What is your daily calorie requirement? Average the two values, and round them to the nearest 25. You will use this number when you complete your dietary project later in this module. Introducing the Nutrients You now know that Canada’s Food Guide to Healthy Living is based on a food plan that includes all six of the nutrient types. Now take a closer look at these six categories, carbohydrates, fats, proteins, minerals, water, and vitamins. Since all digestion processes take place in a liquid environment, water is the sixth component necessary for the proper functioning of the body. Read the following information about water, carbohydrates, proteins and fats. Water It is well known that a person can survive for many days without food, but could survive for only a few days without water (typically 3 and then there may be permanent damage). Besides air, we need water more than anything else, to live. Every cell of our bodies needs water to perform their life functions and to form their structures. Water makes up about 65% of your body’s weight. It is the basis of the body’s transport system (blood and lymph), which transports food, oxygen, and waste products to and from all cells. Water is also important in healing, elimination of wastes, kidney function, and the regulation of body temperature. The average adult should drink approximately 2 litres of water per day. Carbohydrates Carbohydrates are broken down by digestion to produce simple sugars. These simple sugars are an excellent source of fuel for our bodies because when they are oxidized (burned in our bodies). They are completely broken down to carbon dioxide and water, which are easily eliminated. There are various types of carbohydrates, all of which can be broken down into simple sugars for our bodies use as a fuel source. Carbohydrates mostly come from plants and are an excellent source of fiber, A and B vitamins, and many minerals. It is recommended that about 55% of our daily food be carbohydrates. Carbohydrates provide us with 4 calories (units of energy) per gram of carbohydrate. The two basic energy providers are sugar and starch. The sugars can be “simple sugars” such as glucose. Glucose occurs naturally in food and is formed in the body from the digestion of more complex sugars (“double sugars” and starches). Glucose circulates in the body and provides energy to each cell. Simple SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 25 sugars can be found in fruits and honey. About 25% of the total carbohydrate intake comes from sucrose, a “double sugar”. It is found in many foods, but especially concentrated sources are cane and beet sugars, molasses, and maple sugar. Many of our processed foods and sweets use sucrose. Anything on an ingredients label that ends in “ose” is a form of sugar. Starch is the most common of the carbohydrates, providing up to 50% of the carbohydrate intake. Starch is found in seeds, roots, and tubers (such as potatoes). Dietary fiber is a carbohydrate that is part of whole grain food. It makes up the tough fibrous parts of plants. It is very important to our health as it aids in the movement of food through our lower intestinal tract, promoting bowel regularity. Fibre also helps to maintain healthy cholesterol levels in the blood. Healthy carbohydrates include whole grain bread (such as whole wheat or multi grain), whole grain cereals, whole wheat or multigrain pasta, brown rice, potatoes (especially ‘sweet’ potatoes), peas, dried beans, and seeds. Not only do they contain the simple sugars we need, but also the vitamins, minerals and fibre. Vegetables and fruits are another important source of carbohydrates that are rich in vitamins and minerals. Proteins Proteins are complex compounds, essential for life, and make up every cell in your body. It is an important component of your blood, skin, muscle, and hormones. Proteins are large, complex molecules made of simpler building blocks called amino acids. These amino acids can recombine in your body to form various proteins. Twenty biologically active amino acids are used by humans. Ten of these are called essential amino acids because the human body cannot make them, and must be supplied by diet. Lack of any of these would interfere with the normal growth and function. The remaining 10 amino acids are also required in small amounts, however if provided with a balanced diet, the body can produce them. It is recommended that about 15 – 35 % of your daily caloric intake should be protein. Proteins are used for growth, maintenance, and repair of body tissues. They also assist in regulating water balance and maintaining the proper pH of the body. Proteins help form enzymes, antibodies, and even some hormones. Studies have shown that a diet lacking in protein may lower the resistance to infection and delay the healing of wounds. A secondary function of protein is to provide energy to the body when carbohydrates and fats are lacking. This is not ideal and normally only happens when the body is being starved. It also means that under these circumstances the protein is not be used for its primary purposes. Protein containing foods also supply the body with fats, carbohydrates, and vitamins A ,D, E, and K. Both plants and animals provide protein. The best sources are meats of all kinds (such as beef, pork, SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 26 and lamb), poultry (such as chicken and turkey), seafood, eggs, milk, and cheese. Plants also contain proteins. Dry legumes (beans, peas and lentils) and soybeans are excellent choices of protein. Proteins are classified as being either “complete” or “incomplete”. A complete protein contains all of the essential amino acids needed by the body. A protein lacking in any of the ten essential amino acids is called an incomplete protein. Each of the 20 amino acids required by humans is equally important to building a healthy body. Most plant foods are not complete proteins. To increase their nutritional value it is a good idea to serve them in combination with complete proteins. Some examples of complete proteins sources are chicken, fish or turkey. The table below shows food combination to ensure complete amino acid intake for vegetarians. Food Legumes: lentils, peas & beans Grains: wheat, corn , rice Nuts & seeds: almonds, peanuts Amino Acid at Complementary Food Low Level Tryptophan, methionine Grains, nuts & seeds Lysine, isoleucine, threonine Lysine, isoleucine Legumes & dairy Legumes As we can see in the table above, combining grains with nuts and seeds will not provide complete proteins and therefore, legumes will be needed in a strictly vegetarian diet. Fats Fats have been considered precious and valuable as people have struggled for food during history. Literature has recorded many instances where prized fats and oils were saved, rationed, sold or traded. Today, the consumption of fats has become controversial. Our Western diet often tends to be high in fats, which research has shown to increase the risk of heart disease. A little fat is necessary for the proper functioning of the body. Fat makes food taste good. Fats are a rich source of the fat soluble vitamins A, D, E and K. They play an important part in making estrogen in women as well as other hormones in men and women. Fat protects and cushions our vital organs, and insulates against heat loss. Stored fat is helpful in rounding the angular contours of the body. Fat provides the body with the most concentrated form of energy in food, about 9 Calories per gram of fat. Fats stay in the stomach longer than other foods giving a feeling of fullness. It is recommended that 10 – 30 percent of your daily intake of food be fat. Fats are large molecules made from glycerol and three fatty acids. Fats are classified as saturated, monounsaturated or polyunsaturated, depending of the kinds of fatty acids present. Nutritionists advise SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 27 us to cut back on saturated fats because of the health risks associated with their consumption. These fats are usually hard at room temperature, and include animal fats, and the fat in butter and cheese. Saturated fats are also believed to increase the amount of cholesterol in the bloodstream. Monounsaturated fats are a healthier choice and include olive oils, canola oil, and much margarine. They may have a positive effect on the cholesterol levels of the body by lowering Low-density lipoproteins (LDL – “bad” cholesterol). Polyunsaturated fats are the most desirable of the fats. They include foods such as corn oil, fish oils, and soy oils. Research has shown that the presence of polyunsaturated fatty acids in the bloodstream, actually lower the level of cholesterol in the bloodstream. As noted above, fatty acids are the building blocks of fats and oils. Certain of the polyunsaturated fatty acids are essential to the proper functioning of our body. Essential fatty acids (EFAs) are those fatty acids that the body must have in order to function properly. A great deal of research in recent years has been done on the two main groups of EFAs, Omega-6 (also known as linoleic acid) and Omega-3. Omega-6 EFAs are the most common polyunsaturated fatty acids, and are found in foods such as corn oil, safflower oil, walnuts, peanuts, almonds, and sunflower seed and oils. Omega-3 EFAs are abundant in fatty cold water fish (salmon is an excellent source), fish oils, nuts, soybeans, canola oil, flaxseed oil, egg yolks, and the leaves and seed of many plants. Seeds such as flax, sunflower, and pumpkin contain both types of EFAs. It is recommended 1 – 3 grams of omega-3 per day and about 3 times that amount of omega-6 comprise our diet. These EFAs are still being studied, but there is scientific speculation that these fatty acids have benefits in a wide range of medical condition and diseases such as Crohn’s disease, rheumatoid arthritis, and cancer. Experts have stated that we should keep our intake of saturated fatty acids down, and that oils and spreads rich in monounsaturated and polyunsaturated are a healthier choice. New research is emerging that warns us to even be careful of some of the mono and polyunsaturated food because of the possible presence of trans fatty acid (often called trans fats). These fatty acids are twisted out of their normal shape, and researchers are finding that they act to increase our blood cholesterol much like the saturated fats do. The harmful trans fatty acids are present in foods that have been hydrogenated. Hydrogenation is the process where unsaturated fats are changed in to saturated fats by adding more hydrogen. This process is used to produce many margarines and shortenings and spreads, from liquid oils. More research needs to be done in this area, but the concern has been significant enough to stimulate many manufacturers to reduce the amount of trans fats in their products. Cholesterol Cholesterol is another member of the fat family. Cholesterol is a normal useful component of blood and tissues, found in every cell of the body. Some is made by the body, and some is provided by diet. The amount of cholesterol in the diet appears to influence the amount of cholesterol in the blood. If a diet is SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 28 rich in saturated fats, the blood levels of cholesterol are higher than when polyunsaturated food is included. Cholesterol does not dissolve in the blood, and needs to be carried by molecules called lipoproteins. “Low density lipoproteins”, or LDLs and “high density lipoproteins”, HDLs are measures used to check your cholesterol levels, as these are the two most common carriers of cholesterol. HDLs are known as “good cholesterol” and help to carry cholesterol out of the body. LDLs can stick to blood vessels causing clotting, and are thus known as “bad cholesterol”. Most foods contain a combination of carbohydrates, proteins, and fats. A hamburger is an example of a food that contains all three. A healthy choice that contains all three is a turkey sandwich on multigrain bread. Complete Assignment 4 The Micronutrients- Vitamins and Minerals Consuming the proper amounts of vitamins and minerals is a little trickier. Relying on one type of food such as rice or corn may be a valuable source of carbohydrates; however, this narrow diet would deprive your body of some of the vitamins and minerals required by the body. In some parts of the world where food is scarce, and variety is extremely limited, children especially suffer from debilitating illnesses due to a lack of vitamins in their diet. Thirteen substances have been recognized as vitamins. They are defined as distinct chemical compounds that must be present in food to sustain human health. Most are identified as a letter, but all have been given names as more has been learned about their chemical composition. Vitamin C for example is now known to be the compound ascorbic acid. Although vitamins provide neither energy nor material for tissue building, they are necessary to the health of the body. Vitamins help enzymes transform macro nutrients into energy and body tissue. All of the vitamins that are needed in one day add up to one fiftieth of a teaspoon (.10 mL)! For this reason the amounts of vitamins needed daily are measured in milligrams or micrograms. Four vitamins are soluble in fat, but not in water. This is why they usually enter the body with fatty food and vegetables, and stored in body fat. These are vitamins A, D, E and K. The other nine (vitamin C plus the eight B vitamins) are water soluble and are not stored in the body in substantial amounts. Any extras are excreted in the urine. Because they are not stored, we need to consume these each day. Minerals, like vitamins are required in smaller amounts than the macronutrients. Minerals occur in nature, in rocks, and soil. Minerals become a part of our bones, tissues, and fluids. Some minerals are required in relatively large amounts, as much as 0.2 ounces (5 – 6 g) per day. These “major minerals” SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 29 include calcium, phosphorus, sodium, chlorine, potassium, magnesium and sulfur. The “trace minerals” are needed in far smaller amounts. They include manganese, iron, copper, iodine, zinc, fluoride, and perhaps others. The number of minerals known to be essential to human health is past twenty and growing. Minerals serve a variety of functions in the body, but generally the common functions they share include maintaining the rigidity of the skeleton, controlling the water balance of the body, and acting as a component of hormones, vitamins, and enzymes. No one food contains all of the minerals we need; however, a varied diet will provide an adequate supply. Diet and Disease One of the leading causes of death in Canada is cardiovascular disease. Diet has been identified as a major risk factor in the incidence of this disease. The foods that you eat can help you to improve our health or can increase the risk of disease affecting the heart. The diet related factors that are considered to have the biggest impact on heart disease are cholesterol and total amount and kind of fat in the diet as well as a diet that is low in fiber. Smoking, high blood pressure, obesity, stress, and sedentary living are also thought to be major risk factors in heart disease. Cardiovascular disease includes several diseases and disorders of the heart and blood vessels. Three of these are arteriosclerosis, congestive heart failure, and hypertension. Several other diseases and conditions can also be linked to poor diets. Type II diabetes, osteoporosis, some types of cancer, and stroke all have links to an unhealthy diet. There is evidence that some forms of arthritis and ADHD can be improved or made worse by the foods consumed. A lack of vitamin C suppresses the immune system and increases vulnerability to colds, flus, and infections. Those would do not obtain enough vitamin E and vitamin D may experience problems with their skin, bones, and moods. Speaking to your family physician or a dietician is helpful if you believe your diet may be affecting your health in a negative manner. Nutrition and Food Labeling If you want to eat healthier, food package labels can provide you with a wealth of information. You should look for your information in three different places: 1. The Ingredient List (required by law in Canada) This gives us a list of every ingredient used in the product. Ingredients are listed in order of amount used (by weight, not volume). In some cereals, you will see sugar (or glucose or another name for sugar) listed as the first ingredient, and flour listed second. This tells the consumer that there is more sugar than flour in the cereal. This gives you a good clue as to its level of nutrition. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 30 2. Nutrition Claim A nutritional claim is used to highlight a special feature of that particular food. These are usually in big or bold print. A claim gives you some instant information, but not the whole story. By law, if a Nutritional Claim is made, the manufacturer has to provide detailed information about the claim somewhere else on the label. Some examples of nutritional claims are statements like “ A source of….” Or “low in…”. Be careful of some of the words that are used. They can be misleading. Here are some commonly used words, and what they really mean: 3. “No Fat” or “Fat Free” – Contains less than ½ g. of fat per serving “Low Fat” – Contains less than 3 g. of fat per serving “Lite” – Contains 1/3 the calories or ½ the fat per serving of the original version, or a similar product. “Low Calories” – Contains 1/3 the calories of the original version, or a similar product. “No Calories” or “Calorie Free” – Contains less than 5 calories per serving “Low Sodium” – Contains less than 140 mg. of sodium per serving “No Cholesterol” – No animal fat was used in making the product. This does not guarantee that it is low in fat. Nutrition Information (required by law in Canada) Nutrition information is the heading under which you will find the detailed nutrition facts about a product. Since nutrients are always listed in the same order, it makes it easier for you to quickly scan the label for the information you want. Remember that information is usually given “as sold”, without anything else added. For example, a box of cereal will provide information about nutrients in a bowl of cereal, without including the nutrients provided by milk. Here are some key pointers about what you will find under Nutrition Information; a. Serving Size – This tells you the serving size for which the nutrition information is given. Be careful to check how closely your serving size compares to this value. b. Energy – Measured in Calories per serving. c. Fat – Fat shows the total amount of fat in a food. Some labels will be even more specific, and provide information about the various types of fat. It is healthier to find foods with mostly polyunsaturated or monounsaturated fats, but be sure to check the total number of grams of fat. A general rule of thumb is for women to eat less than 65 grams of fat, total each day, and for men to eat less than 90 g. of fat per day. It is important to keep this number in mind because you might choose a food containing 45 g. of fat. Remember that this is more than half of the fat you should eat in one day!! d. Carbohydrates – This includes the content of sugars, starch, and fibre. Sometimes they will be broken down into all three, but other times they will be given as one. It is ideal for adults to consume 25-35 g of fibre each day. A healthy food often contains more than 2 g of fibre per serving. Foods containing 6 g of fibre are very high sources of fiber. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 31 e. Sodium – This is a fancy word for how much salt is in the food. It should be measured in milligrams (mg). As a general guideline, adults should be getting no more than 2300 mg of salt daily. Think twice about buying a can of soup that contains 800-900 mg. of sodium! f. Percentage Recommended Daily Intake- This is the way that vitamins and minerals are usually listed. If you are monitoring your intake of a specific vitamin or mineral, this can be helpful. Let’s have a look at some labels. Here are two labels you might find in the freezer section of your grocery store: Shepherd’s Pie Nutrition Information Per 255 g. Serving (1 package) ________________ Chicken Pot Pie Nutrition Information Per 200 g. Serving (1 package) __________________ Energy Protein Fat Carbohydrate Energy Protein Fat Carbohydrate 310 Cal 18 g 13 g 31 g 444 Cal 13.2 g 24.7 g 42.1 g Take a minute to analyze these products. How do they compare in terms of overall nutrition? Would you agree that the difference in the Chicken Pot Pie seems to come from the fact that it has almost double the fat than the Shepherd’s Pie? As you know, fat contains much more calories than proteins or carbohydrates. Even though the Chicken Pot Pie has more calories it contains less protein than the Shepherd’s Pie. These observations, taken together, make the Shepherd’s Pie a better choice for someone who is trying to keep their fat intake at a reasonable level. The Use of Food Additives Additives have been used for a variety of purposes in food for many years, but in recent years the use of additives has become controversial. As you read the following few pages, ask yourself whether you feel their use is warranted today. Cloves were used many years ago to make ham last longer. It was not known until much later how it worked, but today we know that a chemical in the cloves stops the growth of bacteria. Spices were sought by traders who traveled the South Seas looking for sources of spices that could be brought to their native lands. One of the uses of these spices was to mask the taste of tainted food. Today, food additives are regulated. The number of additives used has grown greatly over the years. It is estimated that over 2500 different additives are used in foods today. The average adult diet contains 70 kg of additives per year (about 93% of this would be refined sugars). In 1961, sparked by the concern for the safety of our foods, the United Nations and the World Health Organization began an international effort to set an acceptable limit of food additives. The acceptable SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 32 limit is called the “acceptable daily intake”(ADI). It is up to each individual country to regulate the use of additives based on these findings. That is why today some food additives differ in acceptable limits, from country to country. Foods are subjected to rigorous tests to determine the ADI. For obvious reasons these are conducted on laboratory animals. They are fed large amounts of the additives to determine what maximum level can be consumed by the animal, without any negative effects. Usually the ADI is set at 1/100th of the maximum amount proved harmless when given to lab animals. For additives that may cause cancer, even this amount may be too high. Thus, the artificial sweeteners saccharin and cyclamate have been banned in some countries, as has the red food colour # 40 as these food additives are known to carcinogenic (cancer causing). How would you feel about eating the food containing the following list of ingredients? “Fructose, sucrose, pectin, hemicellulose, cellulose, formic acid, acetic acid, malic acid, potassium, calcium, phosphorus, caprylic ester, acetaldehyde.” If this list makes you nervous, you may be surprised to learn that this food product is an apple! Some of us can be frightened of food label ingredients that are foreign to us, often listed using scientific names we are not familiar with. The label actually consists of a number of vitamins, minerals and fibers that are necessary for good health. Let us now look at some of the chemicals used as food additives and find out why they are used. Food additives have a variety of purposes. They may be broadly classified into 5 categories, nutrients, preservatives, processing aids, flavourings, and colourings. Let us take a brief look at each of them. Nutrients Vitamins and minerals are added to foods to make up for possible deficiencies or to replace those that are lost during processing. Vitamins A and D are added to milk and margarine to prevent blindness and rickets (bone disease). Other nutrients are added to breads and cereals because some essential vitamins are destroyed in the milling and processing of the grain. Preservatives Preservatives added to food are to prevent unappetizing changes in colour, flavor and texture when food is exposed to air, and to protect food from spoilage by microorganisms. Nitrites are one group of preservatives that receive a fair bit of bad press. Nitrites are used in the curing of pork to kill the organism that causes botulism. Nitrites are also found in a variety of other processed meats, including hot dogs. Nitrites can produce nitrosamines, when combined with other chemicals during digestion. Nitrosamines have been shown to cause cancer. It has also been determined that if nitrites are consumed with vitamin C, the production of nitrosamines is prevented. If you want a hot dog, be sure to drink orange juice with it! It is important to realize that nitrites are present in human saliva, lettuce, beets, celery, and spinach as well. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 33 Another preservative called calcium propionate is a natural food product, found in Swiss cheese. It is also used to slow the growth of mould in breads. Because of the popular wave of protest against additives, some bakers now omit it from their recipes, because without it they can advertise that their bread is “free of preservatives”. Unfortunately molds can cause infections, allergies, and some have even been linked with cancer formation. Is it really worth removing this additive? Processing Aids They do not make food safer, but they improve the texture and taste of a food. Lecithin, for example, keeps the oil and ground peanuts from separating in a jar of peanut butter. Carrageenan, a seaweed derivative helps prevent ice crystals from forming in ice cream. Glycerin maintains moisture in marshmallows, shredded coconut, and candies. Improvers are substances which improve the dough-making characteristics of flour for bread and other baking goods. Some improvers are ascorbic acid, calcium phosphate, ammonium bromate, and chlorine dioxide. Flavorings Sugar and salt make up 93% of the additives consumed annually by the average adult. Both are natural flavorings, but are unhealthy in the great quantities we consume in Canada today. Thousands of other flavorings are eaten in minute quantities. MSG is a traditional flavor enhancer in the Asian cuisine and in Western culture it adds to the flavour of potato chips. It is a sodium salt of glutamic acid, a natural constituent of protein food. It is also found in wheat germ, and processed foods such as soups and meat products. Synthetic production of MSG produces a white crystal which is commonly used as a flavor enhancer. The safety of MSG has been questioned after being linked with “Chinese Food Syndrome”. About 20 minutes after consuming a meal from a Chinese restaurant, victims of this syndrome complain of symptoms that can include burning or numbness of the upper body, chest pain, dizziness, headache, weakness, nausea, and vomiting, and or migraine. Research on mice in the lab has shown that injections of high doses of MSG have caused damage to the brain. Public opinion has led to the removal of MSG in baby foods. The future of its use is uncertain. Colourings Many food dyes are laboratory versions of colours naturally present in food. Others are created synthetically. Colours are used to improve the look of food. The skin of ripe oranges is often mottled with green. Citrus red dye #2 is used to change its colour. Limes are not green but yellow. Dyes are used here too. Even butter is coloured! In the months when cows eat hay rather than grass, the butter produced is not yellow, but white. To improve its look, colour is added. It is the consumer that ironically drives the use of colour in foods. One British grocery chain tried selling raspberry jam and canned green peas without SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 34 any artificial colour added. Sales fell by 50% because the jam was dull brown, and the peas gray or yellow. Dietary Supplements Vitamins and minerals are essential to life. It was generally believed that if we all ate healthy, nutritious, well-balanced diets, we would not need supplements. This belief is now coming under closer scrutiny. There are now many doctors and nutritionists who believe in the value of supplement pills to restore health after illness, disease, and deficiency conditions. Governments around the world set levels of recommended daily allowances (RDAs), which vary widely from country to country depending on dietary habits, availability of foods, and soil conditions for example. It is now being discovered that it is more difficult to meet RDA requirements than originally thought. Even eating a balanced diet does not guarantee meeting all of the requirements for all vitamins and minerals. People who smoke, drink excessively, are pregnant, take contraceptive pills, live in a polluted city, or are under extreme stress can have trouble getting their RDAs from their diet. If your doctor has prescribed a supplement for you, follow the instructions. If not, check with your doctor and / or a dietician before deciding to take a supplement. It is important to look at your diet to see what food groups you are not consuming on a regular basis. This can help to show you what vitamins and minerals you may be lacking. If you do not eat citrus fruit, or tomatoes, you may be low in Vitamin C. You need 45-60 mg of Vitamin C every day to help with tissue repair of bones and teeth. One orange contains 66 mg of Vitamin C and therefore 100% of your RDA for vitamin C. While you may not absorb 100% percent of the Vitamin C present in the orange, vitamin supplementation without professional advice can be dangerous as there are health problems associated with have vitamin levels that are too high. Fruits and vegetables that are darker in colour (orange and red for vegetables and black and blue for fruit) tend to have more vitamins and antioxidants than paler coloured fruits and vegetables. For example, sweet potatoes (yam) has more valuable nutrients than white potatoes. It has been determined that “natural” vitamins which are derived from foods are no better than synthetic vitamins, which are made from chemicals. Supplements in normal amounts or mega doses do not prevent or cure colds, and some can increase the risk of kidney stones and urinary infections. The following is a list of the essential vitamins, in what foods they are found, and their RDAs. Vitamin A B1 (thiamine) B2 (riboflavin) Best source Liver, eggs, butter, dark green or yellow fruits and vegetables Pork, whole grain breads & cereals, nuts peas, beans Milk, eggs, liver & poultry SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 Role in body Cell and body membranes, eye retinas, bones, teeth RDA 4,000 – 5,000 IU Burning carbohydrates for fuel 1.1 – 1.5 mg Cells for energy release from food and for repair 1.3- 1.7 mg 35 B3 (niacin) Dairy products, whole grains, enriched flour & cereals, poultry, lean meats, nuts B6 Liver, lean meats, whole (pyridoxine) grains, milk, & eggs B5 Egg yolks, meat, nuts, whole (pantothenic grains acid) B7 (biotin) Liver, kidney, egg yolks, nuts, most fresh vegetables B12 Eggs, meat, dairy, produce (cobalamin) B9 (folic acid) C D E K Fresh vegetables, poultry, fish, fruit, dairy products All citrus fruits, tomatoes, raw cabbage, potatoes & strawberries Oily fish, fish liver oils, dairy produce & eggs. Some is made in sunlight. Vegetable oils & more Leafy vegetables, most made by intestinal bacteria Proper functioning of digestive system, skin, & nerves. Proper use of fuel and oxygen by cells Proper functioning of nerves and fat metabolism Energy production by cells 14 – 16 mg Skin and circulatory system health 90 – 110 mg Red blood cell production, cell production & nervous system health Red blood cell production, fetal spine development, brain & skull Bones, teeth & other tissue development 2 micrograms Maintaining blood calcium levels, bone growth. 0.25 mg Making cell membranes Normal blood clotting 6 – 9 mg 88 – 110 mg 1 mg 5 – 7 mg 175 – 220 mg 45 – 60 mg Vitamin pills are not a substitute for a healthy diet. For most people, getting enough vitamins is less of a problem than moderating the amounts of calories, fats, and sugar in their diet. If you are not eating the recommended minimum number of servings of the various food groups and eating a variety of foods within each group it is likely that you are not only deficient in vitamins and minerals, but your daily diet is likely to be unbalanced in other ways too. Taking supplements is no substitute for eating a healthy diet. Caffeine Drinks Since the introduction of Red bull in 1997, caffeine drinks have rapidly become part of the Western World’s cultural diet. While the caffeine and sugar (most of these drinks contain large amounts of sugar in addition to the caffeine) in these drinks can temporarily give a fatigued person a burst of energy, these drinks should not be substituted for a healthy diet and regular adequate sleep. The RDA for caffeine is 200 mg or less for adults. This value is smaller for children and adolescents. The table below presents the caffeine content, as well as the percentage of the RDA, of some common energy drinks. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 36 Energy Drink Serving size Caffeine % of RDA (ounces) (mg) 5 Hour Energy 2 138 69 Amazon Energy Drink 12 120 60 Amp 8.4 75 38 Full throttle 16 144 72 Jolt Energy 23.5 280 140 Monster 16 160 80 NOS 16 260 130 Red Bull 8.46 80 40 Rockstar 16 160 80 Rockstar Energy Shot 2.5 200 100 Rockstar Zero Carb 16 240 120 Coca-Cola Classic 12 35 18 Pepsi 12 38 19 Tea (Brewed) 8 47 24 Tim Horton’s (Large) 20 200 100 Starbucks (Tall) 12 260 130 Exceeding RDA of any substance can be dangerous. This is especially true for substances such as caffeine that are stimulants. Some of the side effects of caffeine overdose are high heart rate, high blood pressure, dehydration, irritability, insomnia, stomach pain, vomiting, fever, muscle twitching, and even seizures. Repeatedly exposing your body to these conditions can result in long-term health problems. Teenagers are more vulnerable to these negative effects because their bodies are not fully developed and not as capable of handling such abuse. An adult body is somewhat more able to cope with the abuse but will still suffer in long term. Another practice that continually grows in popularity is combining these energy drinks with alcohol. As mentioned before, caffeine is a stimulant. Alcohol on the other hand is a depressant. These two SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 37 substances have opposite effects on the body. Think of pressing firmly on the brake of your vehicle while pushing the accelerator. You really wouldn’t make much progress. Your vehicle would make a lot of noise and may jolt a bit, but in reality it would go anywhere. Filling your body with two antagonistic (opposite action) drugs simply adds stress to your body. You are adding to the amount of potentially toxic material your liver and kidneys have to process and eliminate in an attempt to keep you healthy despite your disrespectful treatment of it. Complete Assignment 5 Food Handling Proper handling of food is essential to good health and to maximizing the amount of nutrition a person is able to obtain from the food they eat. This is true for food you consume at home and for food consumed in restaurants. Proper food handling can avoid / eliminate situations such as the Listeriosis scare Canada had in 2008, “stomach flus” that circulate from time to time and food poisonings. You may read the material at any of the following websites. http://www.perdue.com/handling/index.html http://www.fightbac.org/content/view/6/11/ (sections under safe food handling) Or other reliable source that will provide you with the information you need to answer the related questions in assignment 6. Complete Assignment 6 Weight Loss Diets In the Western world, society is obsessed with youthfulness and sexiness. It frequently equates these characteristics with a slim and feminine body or a powerful and masculine body. People who seek these physical attributes often begin by searching for an easy way to lose weight, and thus become victims of fad diets that often do more harm than good. Dieters often do not want to make the effort to change poor eating habits, to give up favorite foods, to count calories, or to study nutrition. Instead they fall for the advertising of a seemingly easy way to lose weight fast. Unfortunately this is not the key to successful dieting. Real weight loss does not occur over night and the fad diets are of little value if you do not stay on them. On the next pages techniques for successful weight loss will be described. SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 38 There are five steps to consider in making a weight loss diet successful: 1. Set Reasonable Weight Loss Goals: It is important to see your physician before dieting. Your doctor can help advise you as to what a reasonable weight is for you. If you have to lose a lot weight such as 10 kg (22 pounds) or more, break it up into smaller amounts. When you have lost the first 5 kilograms or pounds, reward yourself by buying a new article of clothing or perhaps a new healthy cookbook. Then start your next short-term goal. Setting short-term goals makes it easier to see results more quickly. Be realistic about the time it takes to lose weight. It is not wise to lose more than 0.4-0.7 kg per week (1 – 2 pounds) especially after you have lost the first 5 to 10 pounds (depending on your starting weight and dietary habits). 2. Increase Your Activity: To lose weight, you must increase your activity. This does not mean that you have to go out and join a fitness center or a sports team. It simply means to become more active in your daily life. If you eat the same amount of food, and walk briskly for 20 - 30 minutes each day, you could lose up to 5 kg each year. Imagine the combination of less calories and activity. Look for ways to add activity to your life. Walk instead of driving when possible; take the stairs instead of the elevator. Find new ways to entertain yourself. Rather than watching TV, go for a long walk with a friend. There are lots of easy ways to incorporate activity into your life. The double bonus is that it is also good for your heart! 3. Eat Only Nutritious Food: It is so easy to run to the vending machines when you are at school and grab a bag of chips or chocolate bar. Unfortunately these are not part of Canada’s Food Guide. If you plan meals before buying groceries, and start with whole fresh foods (or frozen), you will avoid a lot of the fats and sugars that add calories to your food. Monitor what you eat, and be sure that it meets your daily needs. It is helpful to write down what you are eating to be sure you are getting what you need. If you are missing foods from the fruit and vegetable group, chose an apple or banana for a snack, or an assortment of vegetable sticks. Low on dairy products too? What about a homemade smoothie with two types of fruit, some plain yogurt, and some milk? There are two servings of milks and fruits, and one delicious and nutritious snack. Come up with your own ideas! It is important to be careful of diets that ask you to eat foods that do not follow our food guide. Some diets will ask you to eat only one type of food, or high protein and fat, with little carbohydrates. These diets are not healthy, and can lead to serious illness. 4. Consume Fewer Calories: Remember that fat gives you twice the amount of calories as proteins and carbohydrates. You still need some fat, but try and cut out the extra and unnecessary fats. You can try to avoid fried foods, and cut back on the amount of foods that naturally contain fats, like marbled red meat, butter, margarine, and salad dressings. Pay attention to the liquids you drink. Many juices, crystal mixes and pop have a lot of sugar that adds calories but no added nutrition. Another interesting fact here is 1 gram of alcohol has 7 Calories and no nutrition. It is a good idea to set a daily calorie intake level. If you wish to lose one pound in a week, you SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 39 should consume about 500 calories less each day than your recommended daily calorie intake. Never eat less than 1200 calories a day. This is the minimum amount of calories your body can have and still perform its life functions. Don’t feel that you have to stop eating all food with fat in them. Remember that moderation is the key. You can still eat your favorite foods; just eat them less often and in small amounts. Educate yourself about foods - those which are nutritious and those that are not. Find out which are high and which are low calorie foods. Keep a daily log and keep within your limits. 5. Change Your Eating Habits: This is a probably the hardest of all suggestions as what it really means is changing your lifestyle, so that you can have better eating habits. Some common poor habits are: eating in a hurry. Your brain doesn’t get the message that your stomach is full until after it is full and you eat too much. Slow down and chew your food well, this also helps with digestion. social overeating. Your friends encourage you to go to restaurants that serve high calorie, low nutrient foods. Try to stick to the healthy selections if you want to go along. automatic eating. Many of us eat when we watch TV, read or talk on the phone, without even thinking about it. Some of us don’t even realize we are doing it. skipping meals. Usually someone who skips a meal will eat a lot more at the next meal, often more than they would have had if they had not skipped a meal. using food to solve problems. It is important if you overeat, to look at the times you do, and the mood you were in. There is often a correlation between your mood and overeating. These five guidelines are very general but summarize the things to look for in a weight loss diet. The key is moderation and patience. A diet which is based on Canada’s Food Guide, which causes you to lose a pound a week, is the kind of diet that is best. Diverse Diets That Nourish the World For centuries, people all over the world have incorporated nutrition into distinctive traditional diets. From a nutritional standpoint almost every ethnic diet supplies enough of the 40+ nutrients we need, to be healthy. Most diets are built around grain, rice in Japan, corn in Mexico, rye and wheat in Russia. Additional nutrients are derived from whatever fruits, vegetables, and animals the land provides. Although most of the traditional diets are adequate they do have their drawbacks. Some are high in fats, others in salts. Complete 4 of the 8 Activities for this Module Complete Test for this Module SCIENCE IV: PHYSICAL LIFESTYLE AND NUTRITION 2013 - 2014 40