4 questions | Applied Sciences homework help

1. Ernst E. Adverse effects of spinal manipulation: A systematic review. Journal of the Royal Society of Medicine 100:330–338, 2010.

Basic NutritioN coNcepts The wide variety of great-tasting nutritious foods available today gives us more options for healthful eating than ever before. . . . Eating is a fun and enjoyable part of life. There’s no reason good nutrition can’t be too. Doris Derelian, Ph.D., r.D.1 PresiDent, american Dietetic association Good nutrition is neither complicated nor restrictive. Unless you have a severe metabolic disorder or other specific nutrition- related health problem, you can enjoy virtually every food . . . so long as you practice moderation, variety and balance. Victor herbert, m.D., J.D. tracy stoPler KasDan, m.s., r.D.2 “According to his lawyer, making him eat spinach is a violation of his civil rights. He’s suing us for a million dollars.” © medical economics, 1986 ChapteThreenePart Three Chapter Ten Part Three Nutrition and Fitness176

• The fundamental principles of healthy eating are moderation, variety, and balance.
• A sensible diet based on the Dietary Guidelines for Americans and the USDA Food Guidance System will provide adequate amounts of essential nutrients for most people.
• Food product labels must disclose the amounts of fat and several other significant nutrients.
• Consumers seeking nutrition advice should choose their sources carefully.

Keep these poiNts iN MiNd as You studY this chapter Key Concepts N utrition is the science of food and how the body uses it in health and in disease. A working knowledge of basic nutrition will help you make intelligent food choices and protect yourself against the vast array of misinformation you will encounter. This chapter discusses major food components, essential nutrients and their food sources, dietary guidelines, food labeling, and sources of trustworthy nutrition informa- tion. Nutrition quackery and weight control are covered in the following two chapters. The relationship between diet and heart disease is analyzed in Chapter 15. Major Food coMpoNeNts The major nutrient components of food are proteins, car- bohydrates, fats, vitamins, minerals, and water. Proteins, carbohydrates, and fats supply food energy (calories) and are needed in relatively large amounts. They are called macronutrients and are conveniently measured in grams. (Makros is a Greek word that means large.) Practically all foods contain mixtures of proteins, fats, and carbohydrates, although they are commonly clas- sified according to the predominant macrocomponent. Vitamins and minerals are needed in relatively small amounts for specific purposes, mainly to help regulate body functions. They are called micronutrients and are usually measured in milligram (mg) or microgram (µg) amounts. Water is the major component both in foods and in the human body, which is about 60% water. The body’s digestive system breaks food down into molecules small enough to be absorbed through intestinal walls into the bloodstream. The absorbed substances are metabolized and used for energy, growth and repair, and many other body functions. Proteins Proteins, the body’s main structural component, are used to make bone, connective tissue, muscle, skin, hair, and cell membranes. Proteins also function as enzymes, hormones, antibodies, and as part of hemoglobin, which transports oxygen to the tissues. Protein molecules are too large to be absorbed through the walls of the small intestine and into the bloodstream. Digestive processes break proteins down into their component amino acid molecules which are small enough for absorption. Throughout our bodies, amino acids are reassembled into specific proteins needed for bodily structures and functions, or chemically converted for energy. There are about 20 amino acids in the foods we eat, eight or nine of which are essential in the diet because the body cannot manufacture them. The essential amino acids are isoleucine, leucine, lysine, methionine, phenyl- alanine, threonine, tryptophan, and valine; for infants, histidine also is essential. Protein sources are considered complete (of high quality) if they supply all of the essential amino acids in adequate amounts and incomplete (of poor quality) if they do not. Fats (Lipids) Lipid is the general term for fatty substances, includ- ing triglycerides (fats and oils), phospholipids (such as lecithin), and sterols (including cholesterol). In common usage, fats are lipids that are solid at room temperature, and oils are lipids that are liquid at room temperature. The fats commonly found in foods and in the body are triglycerides. Their molecules are composed of glyc- erol (an alcohol) plus three chainlike fatty acids. Fatty acids differ in the length of their molecular chains and their degree of saturation with hydrogen. Those filled to capacity with hydrogen are called saturated fatty acids. Chains that have room for two hydrogen atoms are called monounsaturated fatty acids. Those with room for four or more hydrogen atoms are called polyunsatu- rated. Linoleic acid and alpha-linolenic acid, which are polyunsaturated, are the only lipid nutrients recognized as essential for humans. Lipids in the diet contain many Chapter Ten Basic Nutrition Concepts 177 other fatty acids, but these can be synthesized from other substances and are not essential. Triglycerides can contain combinations of fatty acids of all types. The dominant fatty-acid type determines the characteristics of the triglyceride. Oils tend to be richer in polyunsaturates, but palm oil and coconut oil are saturated. Other saturated fats originate from animals or are vegetable oils with hydrogen added by hydroge- nation, but fish oils are largely polyunsaturated. When oils are hydrogenated, they become pasty. The process changes some unsaturated fatty acids to saturated ones and rearranges others from their natural cis-configuration to trans-fatty acids.4 Cholesterol, an important component of cell membranes, is transported through the bloodstream in cholesterol-protein combinations. High-density lipo- protein (HDL) tends to carry cholesterol away from the arterial walls, and low-density lipoprotein (LDL) tends to deposit it there. Because saturated and trans fats tend to increase LDL levels and thereby increase the risk of coronary heart disease, the amounts in packaged foods must be specified on their labels. Chapter 15 looks closely at the relationships between dietary factors, lipoproteins, and heart disease. Carbohydrates Carbohydrates are composed of carbon, hydrogen, and oxygen. They are excellent sources of energy and supply about half the calories consumed in the average American’s diet. Humans can digest two types of carbo- hydrates: starches and sugars. Sucrose (table sugar), the predominant sugar, is composed of glucose and fructose, both of which are sugars. Lactose (milk sugar) is also a significant dietary sugar. Cellulose, a carbohydrate that is indigestible by humans, is a component of dietary fiber and is not an energy source for humans. Starches are found in all grains from which breads, cereals, and pasta are made, and also in rice, potatoes, and other vegetables. Starches and most types of dietary fiber are complex carbohydrates composed of long chains of glucose molecules. Sugars that contain one or two sugar molecules are called simple carbohydrates. These include table sugar (obtained from sugar cane or sugar beets), honey, and corn syrup (including high- fructose corn syrup). Glucose has been called the universal sugar because it is the basic form of food energy. All carbohydrates must be metabolized by the body into glucose so that the energy in its molecular bonds can be used. Glucose circulates in the blood and is stored in the form of gly- cogen (animal starch), mainly in the liver and some in the muscles. However, most extra calories, regardless of their source, are stored as body fat, a more concentrated form of stored energy than glycogen. If carbohydrate is not supplied in the diet, the body must use a less efficient process (described in Chapter 12) to break down fats and proteins for energy. Many food faddists claim that sucrose is a “deadly poison,” while complex carbohydrates are safer and more desirable. Foods that contain complex carbohy- drates are an important part of a balanced diet. However, as noted by Stare, Aronson, and Barrett3: It is ridiculous to claim that one type of digestible carbohydrate is dangerously inferior to the others when all become glucose in the body anyway. All edible carbohydrates are safe when eaten in moderate amounts. Dietary fiber. Dietary fiber (also called bulk or roughage) refers to plant components that are resistant to digestion by human gastrointestinal secretions. It includes a heterogeneous group of carbohydrate com- pounds (cellulose, hemicellulose, mucilages, pectin, and gums) and also a noncarbohydrate, lignin. Whole-grain foods are a major source of dietary fiber. Bran has 9% to 12% crude fiber; dry beans, lentils, and soybeans have over 4%; roasted nuts have 2.3% to 2.6%. Most fruits and vegetables contain 0.5% to 1% of fiber. Did You Know? Diet has always had a vital influence on health. Until as recently as the 1940s, diseases such as rickets, pellagra, scurvy, beriberi, xerophthalmia and goiter (caused by lack of adequate dietary vitamin D, niacin, vitamin C, thiamin, vitamin A, and iodine, respectively) were prevalent in this country and throughout the world. Today, thanks to an abundant food supply, fortification of some foods with critical trace nutrients, and better methods for determining and improving the nutrient content of foods, such “deficiency” diseases have been virtually eliminated in developing countries. . . . As the diseases of nutritional deficiency have diminished, they have been replaced by diseases of dietary excess and imbalance—problems that now rank among the leading causes of death, touch the lives of most Americans, and generate substantial health care costs. . . . C. Everett Koop, M.D.5 Former Surgeon General U.S. Public Health Service Historical Perspective Part Three Nutrition and Fitness178 Naturally occurring fiber in food is usually a mixture of water-soluble fibers (pectins, gums, and mucilages, which can dissolve in water), insoluble fibers (cellulose and lignin), and combinations of insoluble and soluble fibers (hemicellulose). Oat bran and oatmeal contain relatively large amounts of soluble fiber. Whole wheat contains relatively large amounts of insoluble fiber. Fiber in the intestinal tract holds water, improving the body’s reservoir for hydration. It also makes the feces bulkier (heavier) and softer, which enables them to pass more quickly and easily through the intestines. Low-fiber diets often result in constipation. Epidemiologists have found that prolonged lack of dietary fiber is associated with gastrointestinal, circulatory, and metabolic prob- lems such as diverticulitis (inflamed outpouches in the large intestine), hemorrhoids, increased blood choles- terol levels, obesity, and diabetes.6 Because foods high in fiber have a variety of fiber components and tend to be low in fat, it is difficult to design studies that can test for specific effects of fiber. Much research needs to be done to determine which com- ponents, if any, might be most useful and the amounts of these components that would be optimal. However, it is known that increasing the amount of soluble fiber can help lower high blood-cholesterol levels and that increas- ing total dietary fiber is useful in treating constipation and hemorrhoids. All major scientific groups that have issued dietary guidelines agree that it is desirable for one’s overall diet to contain adequate amounts of dietary fiber. The Food and Drug Administration (FDA) does not believe there is adequate evidence to permit manufacturers to claim that the amount of fiber in individual food products can help prevent cancer or lower the risk of cardiovascular dis- ease, but it does allow claims involving fiber-containing foods as part of a healthful diet (see Table 10-5, page 190). Chapter 15 covers the importance of soluble fiber in the treatment of high cholesterol levels. A study prepared for the FDA by the Federation of American Societies for Experimental Biology (FASEB) recommends that healthy adults consume 20 to 35 g of fiber per day, which corresponds to approximately 10 to 13 g per 1000 calories of food. The report concluded that achieving this level of intake is feasible by select- ing ordinary foods that are currently available and that many Americans already did so.7 Fiber intake can be increased by eating more whole-grain breads and cere- als, fruits, vegetables, legumes, and nuts. But even fiber that occurs naturally should be eaten in moderation. A high-fiber diet can cause one to feel stuffed or bloated; can cause diarrhea; and can interfere with the absorption of iron, copper, zinc, and calcium. Purified fibers and fiber supplements are generally not recommended for individuals who are able to obtain fiber from food. FuNctioNs aNd Food sources oF Major NutrieNts Table 10–1 Nutrient Protein Carbohy- drate Fat Vitamins and minerals Water Major Functions in Body Forms cell structure; supports growth, main- tenance, and repair of tissue; needed for enzymes and hormones Serves as primary energy source; can pro- vide fiber for proper digestive function Serves as concentrated energy source; sup- plies essential fatty acid; carries fat-solu- ble vitamins Perform various functions to help regulate body processes; necessary to obtain en- ergy from foods Transports nutrients; helps regulate body temperature; aids in digestion Best Food Sources Meat, poultry, fish, dry beans, eggs, nuts Milk, yogurt, and cheese Bread, cereal, rice, and pasta Fruits and vegetables Milk group: whole-milk products Meat group: meats, nuts, peanut butter Other sources: butter, margarine, oils, salad dressing, fried foods, and many processed foods Fruits and vegetables: vitamins A and C, folic acid Bread group: B vitamins Milk group: calcium, phosphorus, riboflavin Meat group: B vitamins, iron, zinc Water and other beverages Fruit and vegetable groups Milk group: milk Chapter Ten Basic Nutrition Concepts 179 safe and adequate consumption of individual nutrients. The U.S. Department of Agriculture (USDA) Food Guidance System—now called MyPlate—addresses both nutrient adequacy and disease prevention. Dietary Guidelines for Americans (DGA) The DGA, developed jointly by the U.S. Department of Health and Human Services and the USDA, provides recommendations based on current scientific knowledge about how dietary intake and exercise may reduce risk for major chronic diseases and how a healthful diet may improve nutrition. The guidelines, which are intended for healthy children (age 2 and older) and adults, form the basis of federal food, nutrition education, and in- formation programs. They address the question, “What should Americans eat to have the best chance of staying healthy?” Since 1980, they have been reviewed every 5 years, as required by federal law.8 The 2010 Dietary Guidelines9 include 23 “key rec- ommendations” for the general population and six key recommendations for specific population groups (see Table 10-2). The recommendations are based on two over-arching concepts: 1. Maintain calorie balance over time to achieve and sustain a healthy weight. To curb the obesity epidemic and improve their health, many Americans must decrease the calories they consume and increase the calories they expend through physical activity. The 2008 Physical Activity Guidelines for Americans (see Chapter 14) provide an appropriate standard. 2. Focus on consuming nutrient-dense foods and beverages. A healthy eating pattern limits intake of Vitamins Vitamins are organic (carbon-containing) substances required in tiny amounts to promote one or more specific biochemical reactions. Only tiny amounts are necessary because vitamins are catalysts (substances that initiate or speed up chemical reactions but remain unchanged while performing their tasks repeatedly). Vitamins do not provide energy directly but are part of the enzyme systems needed to release energy from carbohydrates, fats, and proteins. There are 13 known vitamins for humans: four are fat-soluble (A, D, E, and K) and nine are water-soluble (C and the eight B-complex vitamins: thiamin [B1], riboflavin [B2], niacin, B6, B12, folic acid, biotin, and pantothenic acid). Since patients can survive for many years without becoming ill on intravenous feedings fortified with these substances, it appears that no vitamins remain to be discovered. Vitamins must be obtained from food because the human body cannot manufacture them, but a few are also made within the body. Vitamin D is made in the skin when it is exposed to sunlight, and biotin and vitamin K are made by bacteria in the large intestine. Vitamin deficiency diseases are rare in the United States because vitamins are plentiful in the food sup- ply, both naturally and through fortification. Popula- tion groups at risk for deficiency are identified in Chapter 11. Minerals Minerals are inorganic compounds needed in relatively small amounts to help regulate body functions, aid in growth and maintenance of body tissues, and act as cata- lysts for the release of energy. The 17 essential minerals may be categorized as major minerals (macrominerals) or trace minerals (microminerals). The macrominerals are those present in the body in amounts exceeding 5 g: calcium, phosphorus, magnesium, sodium, potassium, chloride, and sulfur. Sodium, potassium, and chloride are called electrolytes because, in solution, they help to conduct electrical currents. The essential trace miner- als are chromium, cobalt, copper, fluoride, iodide, iron, manganese, molybdenum, selenium, and zinc. Table 10-1 identifies the functions and best food sources of the major nutrients. MeetiNg NutrieNt Needs Several sets of federal guidelines are available to help people make intelligent dietary choices. The Dietary Guidelines for Americans (DGA) provide practical advice for healthful food choices. The Dietary Reference Intakes (DRIs) define what is known about the ranges of Smart shoppers pay close attention to nutrition labels. Source: USDA SNAP-Ed Photo Gallery Part Three Nutrition and Fitness180 dietarY guideliNes For aMericaNs 2010: KeY recoMMeNdatioNs9 Table 10-2 Women capable of becoming pregnant • Choose foods that supply heme iron, which is more readily absorbed by the body, additional iron sources, and enhancers of iron absorption such as vitamin C- rich foods.

• Consume 400 micrograms (µg) per day of synthetic folic acid (from fortified foods and/or supplements) in addition to food forms of folate from a varied diet.

Women who are pregnant or breastfeeding • Consume 8 to 12 ounces of seafood per week from a variety of seafood types.

• Due to their methyl mercury content, limit white (albacore) tuna to 6 ounces per week and do not eat tilefish, shark, swordfish, and king mackerel.
• If pregnant, take an iron supplement as recommended by an obstetrician or other health care provider.

Individuals ages 50 years and older • Consume foods fortified with vitamin B12, such as fortified cereals, or dietary supplements. Foods and food components to reduce • Reduce daily sodium intake to less than 2300 mil- ligrams (mg) and further reduce intake to 1500 mg among persons who are 51 and older and those of any age who are African American or have hyperten- sion, diabetes, or chronic kidney disease. The 1500 mg recommendation applies to about half of the U.S. population, including children, and the majority of adults.

• Consume less than 10 percent of calories from satu- rated fatty acids by replacing them with monounsatu- rated and polyunsaturated fatty acids.
• Consume less than 300 mg per day of dietary cholesterol.
• Keep trans fatty acid consumption as low as possible, especially by limiting foods that contain synthetic sources of trans fats, such as partially hydrogenated oils, and by limiting other solid fats.
• Reduce the intake of calories from solid fats and added sugars.
• Limit the consumption of foods that contain refined grains, especially refined grain foods that contain solid fats, added sugars, and sodium.
• If alcohol is consumed, it should be consumed in mod- eration—up to one drink per day for women and two drinks per day for men—and only by adults of legal drinking age.

Food and nutrients to increase. Meet the following recommendations as part of a healthy eating pattern and while staying within calorie needs. • Increase vegetable and fruit intake. • Eat a variety of vegetables, especially dark-green and red and orange vegetables and beans and peas.

• Consume at least half of all grains as whole grains. Increase whole-grain intake by replacing refined grains with whole grains.
• Increase intake of fat-free or low-fat milk and milk products, such as milk, yogurt, cheese, or fortified soy beverages.
• Choose a variety of protein foods, which include seafood, lean meat and poultry, eggs, beans and peas, soy products, and unsalted nuts and seeds.
• Increase the amount and variety of seafood consumed by choosing seafood in place of some meat and poultry.
• Replace protein foods that are higher in solid fats with choices that are lower in solid fats and calories and/or are sources of oils.
• Use oils to replace solid fats where possible. • Choose foods that provide more potassium, dietary fiber, calcium, and vitamin D, which are nutrients of concern in American diets. These foods include vegetables, fruits, whole grains, and milk and milk products.

Balancing calories to manage weight • Prevent and/or reduce overweight and obesity through improved eating and physical activity behaviors.

• Control total calorie intake to manage body weight. For people who are overweight or obese, this will mean consuming fewer calories from foods and beverages.
• Increase physical activity and reduce time spent in sedentary behaviors.
• Maintain appropriate calorie balance during each stage of life—childhood, adolescence, adulthood, pregnancy and breastfeeding, and older age.

Building healthy eating patterns • Select an eating pattern that meets nutrient needs over time at an appropriate calorie level.

• Account for all foods and beverages consumed and assess how they fit within a total healthy eating pattern.
• Follow food safety recommendations when preparing and eating foods to reduce the risk of foodborne illnesses.

Chapter Ten Basic Nutrition Concepts 181