NUTRITION AND DIETS - Principles of Health Sciences 1 – 1 - ثاني ثانوي

Link to digital lesson CHAPTER www.len.edu.sa 8 NUTRITION AND DIETS Case Study Investigation Noura loves her new job as a residential assisted living dietician. She enjoys getting to know the residents and learning about their dietary requirements in order to design a meal plan for them. She must keep in mind disease process, cognition, and physical limitations as well. Haya has been living at the residential home for three years. She has a BMI of 34, a history of stroke, hypertension, diabetes mellitus, and has recently broken her lower denture. At the end of this chapter you will be asked what considerations Noura needs to keep in mind as she creates a meal plan for Haya. LEARNING OBJECTIVES After completing this chapter, you should be able to: ⚫ Define the term nutrition and list the effects of good and bad nutrition. • Name the six groups of essential nutrients and their functions and sources. ⚫ Differentiate between the processes of digestion, absorption, and metabolism. • Create a sample daily menu using the five major food groups. • Use the body mass index (BMI) graph to determine an individual's BMI. ⚫ Calculate an individual's daily required caloric intake to maintain current weight. • Name, describe, and explain the purposes of at least eight therapeutic diets. KEY TERMS absorption antioxidants cellulose digestion minerals nutrition balanced diet essential nutrients obesity body mass index (BMI) fats proteins calorie lipids vitamins carbohydrates metabolism وزارة التعليم Ministry of 3.0CHAPTER 8 2022-1444 GE44.PATHWAYS.G02.S2.HLTH.SB.indb 130 14/10/2022 10:14

8:1 FUNDAMENTALS OF NUTRITION Nutrition includes all body processes relating to food. These include diges- tion, absorption, metabolism, circulation, and elimination. These processes allow the body to use food for energy, maintenance of health, and growth. Nutritional status refers to the state or condition of a person's nutrition. The goal is to be in a state of good nutrition and to maintain wellness, with optimal body function. Nutrition plays a large role in determining height, weight, strength, skeletal and muscular development, physical agility, and resistance to disease. The immediate effects of good nutrition include a healthy appearance, a well- developed body, proper sleep and bowel habits, and a high energy level. In addition, the effects of good nutrition accumulate throughout life and may prevent or delay diseases or conditions such as: ⚫ Hypertension: high blood pressure; may be caused by an excess amount of fat (increased body weight) or salt in the diet; can lead to diseases of the heart, blood vessels, and kidneys. ⚫ Atherosclerosis: narrowing of the arteries by the accumulation of fatty substances on their inner surfaces; thought to be caused by a diet high in saturated fats and cholesterol; can lead to heart attack or stroke. Osteoporosis: condition in which bones become porous (full of tiny openings) and break easily; one cause is long-term deficiencies of calcium, magnesium, and vitamin D. • ⚫ Diabetes mellitus: metabolic disease caused by an insufficient secretion or use of insulin leading to increased blood glucose (sugar) levels, lack of exercise, and diets high in carbohydrates and sugars contribute to individ- uals developing this disease. ⚫ Malnutrition: the state of poor nutrition; may be caused by poor diet or illness. Symptoms include fatigue, being overweight or under-weight, having a poor complexion, and lifeless hair, and irritability (Figure 8-1). Malnutrition can cause deficiency diseases, poor muscular and skeletal development, reduced mental abilities, and even death. Malnutrition is most likely to affect individuals living in extreme poverty, and patients undergoing drug therapy, such as treatments for cancer. checkpoint 1. Define nutrition. 2. List four (4) diseases that may be avoided by good nutrition. وزارة التعليم Minist of Education 2022-1444 FIGURE 8-1 This child shows many of the signs of severe malnutrition. Courtesy of the Carters for Disease Control Public Heath Image Library NUTRITION AND DIETS 131 | GE44.PATHWAYS.G02 S2.HLTH.SB.indb 131 14/10/2022 10:14

FIGURE 8-2 Essential nutrients include include pro- tein sources. 8:2 ESSENTIAL NUTRIENTS Essential nutrients (Figure 8-2) are composed of chemical elements found in food. They are used by the body to perform many different body functions. As the body uses these elements, they are replaced by elements in the food one eats. The essential nutrients are divided into six groups. The six groups and the specific functions of each group are shown in Table 8-1. CARBOHYDRATES Carbohydrates are the major source of readily usable human energy. They are commonly called starches or sugars. Carbohydrates are a cheaper source of energy than proteins and fats because they are mainly produced by plants. They are easily digested, grow well in most climates, and keep well without refrigeration. They are made of carbon, hydrogen, and oxygen. The main sources of carbohydrates are breads, cereals, noodles or pastas, crackers, potatoes, corn, peas, beans, grains, fruits, sugar, and syrups. Cellulose is the fibrous, indigestible form of plant carbohydrate. It is import- ant because it provides bulk in the digestive tract and causes regular bowel movements. The best sources of cellulose are bran, whole-grain cereals, and fibrous fruits and vegetables. LIPIDS (FATS) Lipids, commonly called fats and oils, are organic compounds found in food- stuffs and in the human body. Lipids also are made of carbon, hydrogen, and oxygen, but they contain more oxygen than carbohydrates do. Fats provide the most concentrated form of energy but are a higher calorie option than carbohydrates. They provide insulation, cushion organs and bones, aid in the absorption of fat-soluble vitamins, and provide flavor to meals. The main sources of fats include butter, margarine, oils, cream, fatty meats, cheeses, and egg yolks. Fats are also classified as saturated or polyunsaturated. Saturated fats are usually solid at room temperature and are found in animal-based foods. Examples include the fats in meats, eggs, whole milk, cream, butter, and cheeses. Polyunsaturated fats are usually soft or oily at room temperature and are found in plant-based foods. Examples include vegetable oils, margarines and other products made from vegetable oils, fish, and peanuts. One type of polyunsat- urated fat that seems to decrease the risk of coronary artery disease is omega-3 fatty acid. It is found in fatty fish such as salmon, tuna, trout, mackerel, sardines, and herring. وزارة التعليم Minist 132 CHAPTER 8 2022-1444 GE44.PATHWAYS.G02 S2.HLTH SB.indb 132 14/10/2022 10:14

Cholesterol is a sterol lipid found in body cells and animal products. It is used in the production of steroid hormones, vitamin D, and bile acids. Cholesterol is also a component of cell membranes. Common sources are egg yolks, fatty meats, shell- fish, butter, cream, cheeses, whole milk, and organ meats (liver, kidney, and brains). In addition, cho- lesterol is synthesized (manufactured) by the liver. PROTEINS Proteins are made of carbon, hydrogen, oxygen, and nitrogen, and some also contain sulfur, phosphorus, iron, and iodine. TABLE 8-1 The Six Essential Nutrient Groups Nutrient Group Carbohydrates Lipids (Fats) Proteins Vitamins Minerals Water Functions Provide heat and energy Supply fiber for good digestion and elimination Provide fatty acids needed for growth and development Provide heat and energy Carry fat-soluble vitamins (A, D, E, and K) to body cells Build and repair body tissue Provide heat and energy Help produce antibodies Regulate body functions Regulate body functions Build and repair body tissue Build and repair body tissue Carries nutrients and wastes to and from body cells Regulates body functions Proteins are made up of 22 "building blocks" called amino acids. Nine of these amino acids are essential to life. The proteins that contain all nine essential amino acids are called complete proteins. The best sources of complete proteins are animal foods such as meats, fish, poultry, milk, cheeses, and eggs (Figure 8-2). Proteins that contain any of the remaining 13 amino acids and some of the nine essential amino acids are called incomplete proteins. Sources of incomplete proteins are usually plant foods such as cereals, soybeans, dry beans, peas, corn, and nuts. Choosing plant foods carefully can provide a mixture of amino acids from incomplete proteins that contain all the essential amino acids. It is important for a vege- tarian to select foods that meet these dietary needs. VITAMINS Vitamins are organic compounds that are essential to life. They are important for metabolism, tissue building, and other body processes. They allow the body to use the energy provided by carbohydrates, fats, and proteins. Only small amounts of vitamins are required, and a well-bal- anced diet usually provides the required vitamins. An excess amount of vitamins or a deficiency of vitamins can cause poor health. Some vitamins are antioxidants, organic mol- ecules that help protect the body from harmful chemicals called free radicals (Figure 8-3). In the body, oxygen used during metabolism causes free radicals to form. Free radicals can damage tissues, cells, and even genes in the same way that oxygen causes metals to rust or apples to become brown. Research indicates that free radicals can lead to the development of chronic diseases such as cancer, reart disease, and arthritis. Antioxidants, found FIGURE 8-3 Antioxidants found in these foods help mainly in fruits and vegetables, deactivate the free وزارة التعليم Ministry of EductION 2022-1444 to protect the body. NUTRITION AND DIETS 133 | GE44.PATHWAYS.G02 S2.HLTH SB.indb 133 14/10/2022 10:15

وزارة التعليم Minst 134 CHAPTER 8 2022 1444 GE44.PATHWAYS.G02 S2.HLTH.SB.indb 134 radicals and prevent them from damaging body cells (Figure 8-2). The main antioxidant vitamins are vitamins A, C, and E. Vitamins are usually classified as water soluble or fat soluble. Water-soluble vitamins dissolve in water; are not normally stored in the body; and are easily destroyed by cooking, air, and light. Fat-soluble vitamins dissolve in fat; can be stored in the body; and are not easily destroyed by cooking, air, and light. Some of the vitamins along with their sources and functions are listed in Table 8-2. MINERALS Minerals are inorganic (nonliving) elements found in all body tissues. They regulate body fluids, assist in various body functions, contribute to growth, and aid in building tissues. Some minerals-such as selenium, zinc, copper, and manganese-are antioxidants. Table 8-2 lists some of the minerals essen- tial to life, their sources, and their main functions. WATER Water is found in all body tissues. It is essential for the digestion (breakdown) of food, makes up most of the blood plasma and cytoplasm of cells, helps body tissues absorb nutrients, and helps move waste material through the body. Total daily intake of water includes water that is found in all foods and beverages. Dietary guidelines state that thirst should be the main indicator of how much water an individual drinks. High external temperatures and a great amount of exercise or physical activity also increase the need for water. A general guideline is that the average person should drink six to eight glasses of water each day to provide the body with the water it needs. checkpoint 1. List the six (6) groups of essential nutrients. 2. According to general guidelines, how much water should the average person drink a day? 14/10/2022 10:15

TABLE 8-2 Some of the vitamins and minerals our bodies need. Vitamins Vitamin A (Retinol) Best Sources Liver, fatty fish Vitamin D (Calciferol) Vitamin E (Tocopherol) Vitamin K Vitamin B (Cobalamin) Vitamin C (Ascorbic Acid) Folic Acid (Folacin, Folate, B.) Calcium (Ca) Butter, margarine Whole milk, cream, cheese Egg yolks Leafy green and yellow vegetables Sunshine (stimulates production in skin) Fatty fish, liver Egg yolks Butter, cream, fortified milk. Vegetable oils, butter, margarine Peanuts, egg yolks Dark green leafy vegetables Soybeans and wheat germ Spinach, kale, cabbage, broccoli Liver, soybean oil, cereals Liver, kidney, muscle meats, seafood Milk, cheese Eggs Citrus fruits, pineapple Melons, berries, tomatoes Cabbage, broccoli, green peppers Green leafy vegetables Citrus fruits Organ meats, liver Whole-grain cereals, yeast Milk and milk products Cheese Salmon and sardines Some dark green leafy vegetables Magnesium (Mg) Meat, seafood Nuts and legumes Milk and milk products Functions Growth and development Health of eyes, skin, and mucous membranes Antioxidant to protect cells from free radicals Growth Regulates calcium and phosphorous absorption and metabolism Builds and maintains bones and teeth Necessary for protection of cell structure, especially red blood cells and epithelial cells Antioxidant to inhibit breakdown of vitamin A and some unsaturated fatty acids Normal clotting of blood Formation of prothrombin Metabolism of proteins Production of healthy red blood cells Maintains nerve tissue Healthy gums Aids in wound healing Aids in absorption of iron Formation of collagen Protein metabolism Maturation of red blood cells Formation of hemoglobin Synthesis of DNA Develops/maintains bones and teeth Clotting of the blood Normal heart and muscle action Nerve function Constituent of bones, muscles, and red blood cells Healthy muscles and nerves Metabolism of carbohydrates and fats Sodium (Na) Potassium (K) Iron (Fe) Fluorine (FI) (Fluoride) Zinc (Zn) Cereal grains Fresh green vegetables Salt Meat, poultry and fish Eggs, milk and cheese Meat Milk and milk products Vegetables Oranges, bananas, prunes, raisins Cereals Liver, muscle meats Dried fruits Egg yolks Enriched breads and cereals Dark green leafy vegetables Fluoridated water Fish, meat, seafood. Seafood, especially oysters Eggs Milk and milk products Fluid balance, acid-base balance Regulates muscles and nerves Glucose (sugar) absorption Fluid balance Regular heart rhythm Cell metabolism Proper nerve function Regulates contraction of muscles Formation of hemoglobin in red blood cells Part of cell enzymes Aids in production of energy Healthy teeth and bones Component of enzymes and insulin Essential for growth and wound healing وزارة التعليم Ministry of EducTRION 2022-1444 GE44.PATHWAYS.G02 S2.HLTH.SBJindb 135 NUTRITION AND DIETS 135 | 14/10/2022 10:15

8:3 USE OF NUTRIENTS Before the body is able to use nutrients, it must break down the foods that are eaten to obtain the nutrients and then absorb them into the circulatory sys- tem. These processes are called digestion and absorption (Figure 8-4). The actual use of the nutrients by the body is called metabolism. DIGESTION Digestion is the process by which the body breaks down food into smaller parts, changes the food chemically, and moves the food through the digestive system. There are two types of digestive action: mechanical and chemical. During mechanical digestion, food is broken down by the teeth and moved through the digestive tract by a process called peristalsis, a rhythmic, wavelike motion of the muscles. During chemical digestion, food is mixed with digestive juices secreted by the mouth, stomach, small intestine, and pancreas. The digestive juices contain enzymes, which break down the food chemically so the nutri- ents can be absorbed into the blood. 1. Mouth: Teeth and tongue begin. mechanical digestion by breaking apart food. 2. Salivary Glands: Begin chemical digestion as salivary amylase begins to change starch into maltose. 3. Esophagus: Peristalsis and gravity move food along. 5. Liver: Produces bille. 6. Gallbladder: Stores bile and releases it through the bile duct into the small intestine to emulsify fats. 8. Small Intestine: Produces enzymes, prepares foods for 4. Stomach: Hydrochloric acid prepares the gastric area for enzyme action. Pepsin breaks down proteins. In children, rennin breaks down milk proteins. Lipase acts on emulsified fats. 7. Pancreas: Enzymes are released into the small intestine. Amylase breaks down starch. Steapsin breaks down fats. Pancreatic proteases break down proteins. absorption. Lactase converts lactose, maltase converts maltose, sucrase converts sucrose to simple sugars. Peptidases reduce proteins to amino acids. FIGURE 8-4 The processes of digestion and absorption. وزارة التعليم Minst 136CHAPTER 8 2022 1444 GE44.PATHWAYS.G02.S2.HLTH SB.indb 136 9. Large Intestine: Absorbs water and some other nutrients, and collects food residue for excretion. 10. Rectum: Stores waste products for excretion. 14/10/2022 10:15

ABSORPTION After the food is digested, absorption occurs. Absorption is the process in which blood or lymph capillaries pick up the digested nutrients. The nutri- ents are then carried by the circulatory system to every cell in the body. Most absorption occurs in the small intestine, but water, salts, and some vitamins are absorbed in the large intestine. METABOLISM After nutrients have been absorbed and carried to the body cells, metabolism occurs. This is the process in which nutrients are used by the cells for build- ing tissue, providing energy, and regulating various body functions. During this process, nutrients are combined with oxygen, and energy and heat are released. Energy is required for voluntary work, such as physical activity, and for involuntary work, such as breathing and digestion. The rate at which the body uses energy just for maintaining its own tissue, without doing any other work, is called the basal metabolic rate, or BMR. The body needs energy con- tinuously, so it stores some nutrients for future use. These stored nutrients are used to provide energy when food intake is not adequate for energy needs. checkpoint 1. Define peristalsis. 2. Where in the body does most of the absorption of nutrients occur? Ministry of Health The Healthy Food Palm For Kingdom of Saudi Arabia Sugars and oils 8:4 MAINTENANCE OF GOOD NUTRITION Good health is everyone's goal, and balanced nutritional diet is the best way to achieve it as our prophet, peace be upon him, urges us to be mod- erate in terms of the food we eat; he says "No man fills a container worse than his stomach. A few morsels that keep his back upright are sufficient for him. If he has to, then he should keep one-third for food, one-third for drink and one-third for his breathing." Accomplishing a balanced diet requires the inclusion of all the essential nutrients in correct amounts. The simplest guide for planning healthy meals is the Healthy Food Palm guide from the Saudi Ministry of Health, which classifies foods into وزارة التعليم Ministige Education 2022-1444 GE44.PATHWAYS.G02 S2.HLTH SB.indb 137 and Vegetables Cereal Physical activity of 30-60-day spending health FIGURE 8-5 The Healthy Food Palm. NUTRITION AND DIETS 137 | 14/10/2022 10:15

وزارة التعليم Minst 138 CHAPTER 8 2022-1444 GE44.PATHWAYS.G02 S2.HLTH SB.indb 138 seven major food groups (Figure 8-5). Foods are arranged in groups contain- ing similar nutrients. Sound and sensible nutritional principles can be found on the Internet at www.moh.gov.sa. checkpoint How many food groups are there? Name them. 8:5 WEIGHT MANAGEMENT Math Good nutrition and adequate exercise allow an individual to maintain a body weight that is in proportion to body height. One indication of an individual's health status is body mass index. Body mass index (BMI) is a calculation that measures weight in relation to height. It is deter- mined by dividing a person's weight in kilograms by height in meters squared. A graphic chart showing BMI ranges is the easiest way to determine BMI (Figure 8-6). A calculator to determine BMI is also available at the Ministry of Health Internet site, www.moh.gov.sa. The ideal range is 18.5 to 24.9. A BMI less than 18.5 indicates the individual is underweight. A BMI from 25 to 29.9 indicates the individual is overweight and has increased health risks. A BMI of 30 and above indicates obesity and much higher health risks. UNDERWEIGHT AND OVERWEIGHT Weight management is used to achieve and maintain the desired body weight. The major conditions that occur due to poor nutrition and improper exercise are underweight, overweight, and obesity. Underweight is a body weight when the BMI is less than 18.6, and is con- sidered too low to be healthy. Underweight individuals are much more likely to have nutritional deficiencies. Causes can include an inadequate supply of or intake of food, excessive exercise, severe infections, and diseases and/ or treatments that cause anorexia (lack of appetite) such as chemotherapy for cancer. However, the most common cause is eating disorders, which can lead to severe malnutrition and even death. Individuals who develop eating disorders may start by dieting to lose weight but then become obsessed with controlling the amount of food they consume. A poor self-image, emotional stress, unsatisfactory social relationships, peer pressure, the desire to resem- ble slim fashion models, obsessive-compulsive personality traits, an extreme drive for perfectionism, and even genetic influences may cause an individual to develop eating disorders. Eating disorders are more common in females and often develop during adolescence or early adulthood. Some of the most common eating disorders include: 14/10/2022 10:15

Body Mass Index Table BMI Height Normal Overweight Obese Exteme Obesity 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 Body Weight (kg) (cm) 147 41 44 45 48 50 150 43 45 152 44 46 49 51 54 52 54 56 59 47 49 52 54 56 58 60 63 56 58 60 61 63 65 67 69 72 73 76 78 80 82 84 87 89 91 93 95 98 65 67 69 72 74 76 78 81 83 85 88 90 92 94 96 98 101 63 65 67 69 72 74 76 79 81 83 155 45 48 50 53 55 58 60 62 65 67 69 72 74 77 79 82 84 86 157 47 49 52 54 57 59 62 64 67 69 72 74 77 79 82 84 87 89 86 88 90 93 95 98 100 102 104 88 91 93 96 98 101 103 105 108 92 94 97 99 102 104 107 109 112 160 49 51 54 56 59 61 64 66 69 72 74 77 79 82 84 87 89 92 163 50 53 55 58 61 64 66 68 71 74 77 79 82 84 87 89 93 95 165 52 54 57 60 63 65 68 71 73 76 79 82 84 87 90 93 95 94 97 100 102 105 108 110 112 115 98 100 103 105 108 111 113 116 119 98 101 103 106 109 112 114 117 120 122 168 54 56 59 62 64 67 70 73 76 78 81 84 87 90 93 95 98 101 104 107 109 112 115 118 121 123 126 170 55 58 61 64 66 69 72 75 78 81 84 87 90 93 96 98 101 104 107 110 113 116 118 122 124 127 130 173 57 59 63 65 68 72 74 78 80 83 86 89 92 95 175 58 61 64 68 70 73 77 80 83 86 89 92 95 178 60 63 66 69 73 76 79 82 85 88 92 95 180 62 65 68 71 75 78 81 84 88 91 98 101 104 107 110 113 116 119 122 125 128 131 134 98 101 104 107 110 113 117 119 122 126 129 132 135 138 98 101 104 107 110 113 117 120 123 126 129 132 136 139 142 94 98 101 104 107 110 113 117 120 123 127 130 133 137 140 143 146 183 64 67 70 73 77 80 83 87 90 93 97 100 103 107 110 113 117 120 123 127 130 133 137 140 143 147 150 185 65 68 72 75 79 83 188 67 70 74 78 86 89 93 96 191 69 73 76 80 99 103 107 110 113 117 120 123 127 131 134 137 141 144 147 151 154 81 84 88 92 95 99 102 106 109 113 116 120 123 127 130 134 137 141 145 148 152 155 159 83 87 91 94 98 102 105 109 112 116 120 123 127 130 134 137 141 145 148 152 156 159 163 193 71 74 78 82 86 89 93 97 100 104 108 112 115 119 123 127 130 134 138 142 145 148 152 156 160 164 167 FIGURE 8-6 Body mass index (BMI) helps individuals determine healthy weight ranges. ⚫ Anorexia nervosa: commonly called anorexia; a psychological disorder in which a person drastically reduces food intake or refuses to eat at all. ⚫ Bulimia: a psychological disorder in which a person alternately binges (eats excessively) and then fasts, or refuses to eat at all; in some cases, a person will exercise excessively after binging. ⚫ Bulimarexia: a psychological disorder in which a person alternately binges and then induces vomiting or uses laxatives to get rid of food that has been eaten. Physical symptoms of eating disorders include excessive weight loss, extreme weakness and fatigue, irregular heart rhythms, low blood pressure, amenor- rhea (absence of menstruation), thin or brittle hair that falls out, an intoler- ance to cold, dehydration, constipation, dry skin, metabolic disturbances, and osteoporosis. Individuals with a disorder may refuse to eat or lie about eating habits, monitor weight constantly, exercise excessively, withdraw from social Situations use laxatives or diet aids frequently, and have a distorted body image. Death can occur if the condition is not treated. Treatments for eating وزارة التعليم Ministry of Eduction 2022-1444 NUTRITION AND DIETS 139 | GE44.PATHWAYS.G02.S2.HLTH.SB.indb 139 14/10/2022 10:15

وزارة التعليم Minist 140 CHAPTER 8 2022-1444 disorders include medical intervention for severe physical symptoms such as irregular heart rhythms and metabolic disturbances, and psychotherapy or counseling to allow the individual to develop behavioral patterns that main- tain a healthy weight. Overweight is a body weight that is 10 to 20 percent greater than the average recommended weight for a person's height, or a BMI from 25 to 29.9. Obesity is excessive body weight 20 percent or more above the average recommended weight, or a BMI equal to or greater than 30. Obesity has become a major health concern in the Kingdom of Saudi Arabia. According to the World Health Organization,: ⚫ Around 36 percent of the population are overweight and 25 percent are classed as obese. • More than 23 percent of Saudi children 5-18 years are overweight and over 11 percent are obese. ⚫ Health problems associated with overweight and obesity have a significant economic impact on the Saudi health care system. The main causes of obesity are excessive calorie consumption and inadequate physical activity. Genetic, psychological, and biochemical (metabolic) factors can also contribute to this condition. Treatment involves modifying eating habits and increasing physical activity. In more severe cases, medical inter- vention with medications, counseling, and even surgery may be necessary. If obesity is not controlled, an individual is at high risk for development of hypertension, diabetes mellitus, coronary heart disease, high cholesterol, cere- brovascular accident (stroke), osteoarthritis, gallbladder disease, breathing problems such as sleep apnea, and certain types of cancer such as breast and colon cancer. Research has also shown that obesity decreases life span and causes many early deaths. MEASURING FOOD ENERGY Foods vary in the amount of energy they contain. For example, a candy bar provides more energy than an apple does. When the body metabolizes nutri- ents to produce energy, heat is also released. The amount of heat produced during metabolism is the way the energy content of food is measured. This heat is measured by a unit called a calorie. The number of calories in a certain food is known as that food's caloric value. Carbohydrates and proteins provide four calories per gram. Fat provides nine calories per gram. Vitamins, miner- als, and water do not provide any calories. An individual's caloric requirement is the number of calories needed by the body during a 24-hour period. Caloric requirements vary from person to per- son, depending on activity, age, size, sex, physical condition, and climate. The amount of physical activity or exercise is usually the main factor determining caloric requirement because energy used must be replaced. An individual who wants to gain weight can decrease activity and increase caloric intake. An indi- vidual who wants to lose weight can increase activity and decrease caloric intake. GE44.PATHWAYS.G02 S2.HLTH SB.indb 140 14/10/2022 10:15

MANAGING WEIGHT Most people know that maintaining desired body weight can lead to a longer and healthier life. Research has shown that even though diets might be benefi- cial or lead to weight loss, they usually do not allow an individual to maintain their weight when the diet is no longer used. Most fad diets require eating spe- cific foods, limiting certain food groups, eating large amounts of one type of food, or using liquid supplements in place of food. When individuals resume their normal eating habits, the weight that was lost is quickly regained. The best method for weight control is to make desired changes slowly. Research has shown that gradual weight loss with a change in habits is much healthier and more likely to be sustained. For example, a person who never exercises may start by walking at a slow pace for 15 minutes every day. Gradually, the time and rate can be increased until the person is walking at a brisk pace for 30 minutes 5 days a week. At the same time that the amount of exercise increases, the number of calories consumed must change. Before starting any diet or weight management plan, a physician should be consulted. The physician may perform a physical examination, order blood or other laboratory tests to check for diseases that could affect weight, run an electrocardiogram, or order a stress test to determine cardiovascular fitness. The physician can then recommend a nutrition plan and exercise program that is customized to the individual's needs. A general guideline for weight loss or gain is that 1 kilogram of body fat equals approximately 7,700 calories. To lose 1 kilogram, a decrease of 7,700 calories is required, either by consuming 7,700 fewer calories or by using 7,700 calories through increased exercise. To gain 1 kilogram, an increase of 7,700 calories is required. It is important to note that increasing or decreasing exercise along with controlling calorie intake is essential. Also, a slow, steady gain or loss of 0.5 kg per week is an efficient and safe form of weight control. Some recommendations for managing weight include: ⚫ Balance calories from foods and beverages with calories expended. ⚫ Make small decreases in daily calories and small increases in physical activity. ⚫ Engage in at least 30 minutes or more of moderate-intensity physical • activity most days of the week with a weekly goal of at least 150 minutes. Consume less than 10 percent of calories from saturated fatty acids. ⚫ Keep daily total fat intake to between 20 and 35 percent of calories consumed. Select lean, low-fat, or fat-free foods whenever possible. ⚫ Eat more fiber-rich fruits, vegetables, and whole grains. Limit foods high in sugar and salt. وزارة التعليم Minister EductION 2022-1444 GE44.PATHWAYS.G02 S2.HLTH SB.indb 141 NUTRITION AND DIETS 141 | 14/10/2022 10:15

وزارة التعليم Minst 142CHAPTER 8 2022 1444 GE44.PATHWAYS.G02.S2.HLTH.SB.indb 142 Following these recommendations can help an individual reduce the risk for heart disease, hypertension, diabetes mellitus, high cholesterol, and certain cancers, and also allow the individual to enjoy a longer and healthier life span. checkpoint What is the best method for weight control? 8:6 THERAPEUTIC DIETS Therapeutic diets are modifications of the normal diet to improve specific health conditions. They are normally prescribed by a doctor for specific health conditions, and for short periods of time, and are planned by a dietitian. These diets may change the nutrients, caloric content, or texture of the normal diet. They may seem strange and even unpleasant to patients, so it is essential that the health care provider use patience and tact to convince the patient to eat the foods on the diet. An understanding of the purposes of the various diets will also help the health care provider give simple explanations to patients. REGULAR DIET A regular diet is a balanced diet usually used for the patient with no dietary restrictions. At times, it has a slightly reduced calorie content. Foods such as rich desserts, cream sauces, salad dressings, and fried foods may be decreased or omitted. LIQUID DIETS Liquid diets include both clear liquids and full liquids. Both are nutritionally inadequate and should be used only for short periods of time. All liquids must be served at body temperature. These diets may be used after surgery, for patients with acute infections or digestive problems, to replace fluids lost by vomiting or diarrhea, and before some x-rays of the digestive tract. SOFT DIET A soft diet is similar to the regular diet, but foods must require little chewing and be easy to digest. Foods to avoid include meat and shellfish with tough connective tissues (most meat is ground), coarse cereals, spicy foods, rich desserts, fried foods, raw fruits and vegetables, nuts, and coconut. This diet may be used following surgery or for patients who have infections, digestive disorders, dysphagia (difficulty in swallowing), or chewing problems. 14/10/2022 10:15

DIABETIC DIET A diabetic diet is used for patients with diabetes mellitus. In this condition, the body does not produce enough of the hormone insulin to metabolize car- bohydrates. Patients frequently take insulin by injection. The diet is called a carbohydrate-controlled diet because patients must calculate the amount of carbohydrates in each meal. Usually approximately 40-60 percent of calo- ries are from carbohydrates. In some cases, calorie levels are controlled in addition to the amount of carbohydrates. CALORIE-CONTROLLED DIETS Calorie-controlled diets include both low-calorie and high-calorie diets. Low- calorie diets are frequently used for patients who are overweight. High-calorie foods are either prohibited or very limited. High-calorie diets are used for patients who are underweight. Extra proteins and carbohydrates are included. LOW-CHOLESTEROL DIET A low-cholesterol diet restricts foods that contain cholesterol and usually limits fats to less than 50 grams (g) daily. It is used for patients who have atheroscle- rosis and heart disease. FAT-RESTRICTED DIETS Fat-restricted diets, also called low-fat diets, usually limit fats to less than 50 grams (g) daily. Fat-restricted diets may be used for obese patients or patients who have gallbladder and liver disease or atherosclerosis. SODIUM-RESTRICTED DIETS Sodium-restricted diets are also called low-sodium or low-salt diets. Low- sodium-diet lists provide the amount of sodium present in a specific food. Patients should avoid or limit adding salt to food and avoid smoked meats or fish, processed foods, pickles, olives, sauerkraut, and some processed cheeses. This diet reduces salt intake for patients who have cardiovascular diseases (such as hypertension or congestive heart failure), kidney disease, and edema (retention of fluids). PROTEIN DIETS Protein diets include both low-protein and high-protein diets. Protein-rich foods include meats, fish, milk, cheeses, and eggs. These foods are limited or decreased in low-protein diets and increased in high-protein diets. Low- protein diets are ordered for patients who have certain kidney or renal diseases and certain allergic conditions. High-protein diets may be ordered for children and adolescents with growth delay; for pregnant or lactating (milk-producing) women and for patients suffering from burns, fevers, or infections. وزارة التعليم Minister Educ 2022-1444 GE44.PATHWAYS.G02 S2.HLTH SB.indb 143 NUTRITION AND DIETS 143 14/10/2022 10:15

BLAND DIET A bland diet consists of easily digested foods that do not irritate the digestive tract. This diet is used for patients who have gastric (stomach) disorders, coli- tis, and other diseases of the digestive system. FIBER DIETS Fiber diets are usually classified as high fiber or low fiber. A high-fiber diet usually provides at least 30 grams (g) of fiber without seeds or nuts. It is used to stimulate activity in the digestive tract, such as for constipation. A low-fiber or low-residue diet containing less than 10-15 grams of fiber per day elimi- nates or limits foods that are high in bulk and fiber. It is used for patients who have digestive and rectal diseases, such as colitis or diarrhea. checkpoint What is the difference between a regular diet and a therapeutic diet? Case Study Investigation Conclusion Haya has several medical conditions that Noura will have to address when she makes her dietary recommendations. What other physical restrictions should she consider? Should Noura give Haya's food preferences any consideration? What other things do you think will impact Noura's menu plan? Today's Research Tomorrow's Health Care A Daily Pill That Prevents Cardiovascular Disease and Alzheimer's Disease? Cardiovascular (heart and blood vessels) disease is the main cause of death worldwide. Scientists at the University of Chester in the United Kingdom and at Kent State University in Ohio have developed two new vitamin compounds that could reduce the risk of these diseases. Working as an international team, they are evaluating the effectiveness of the vitamins in reducing elevated blood levels of an amino acid, homocysteine. Homocysteine is acquired mainly by eating meat. It increases the risk of cardiovascular disease and Alzheimer's disease because it produces large amounts of free radicals that interfere with the way body cells use oxygen. Even though vitamin B₁, and folic acid are somewhat effective in breaking down the homocysteine in the body, researchers have found that the new compounds are four times more effective. Tests were carried out using human vascular cells in a model cell system. Results indicated that the compounds reduced the inflammation caused by the homocysteine in vascular cells. Clinical trials will have to be conducted to determine if there are any adverse effects from the compounds. If the trials are successful, the researchers estimate that in 5-6 years a new vitamin medication could be available. In addition to cardiovascular disease and Alzheimer's disease, elevated blood levels of homocysteine may be associated with osteoporosis (bones become porous), pregnancy complications, and other inflammatory disorders. If a vitamin compound could reduce the risk of these conditions, thousands of lives could be saved each year. وزارة التعليم Ministro 144 CHAPTER 8 2022 1444 GE44.PATHWAYS.G02.S2.HLTH.SB.indb 144 14/10/2022 10:15