chapter 4
Nutrition
After studying this chapter, the student should be able to:
1 Identify five principles of nutrition as presented in this chapter.
2 Describe the functions of nutrients found in the foods people eat.
3 Explain the strategies of the Dietary Guidelines for Americans 2010.
4 Review importance of economic considerations in meal planning.
5 Describe nutrition throughout the life cycle.
6 Demonstrate a beginning understanding of both standard hospital diets and diets ordered for specific conditions.
http://evolve.elsevier.com/Mosby/comprehensivePN
HEALTH PROMOTION
A Goal: to increase the level of health of individuals, families, groups, and communities; requires a lifestyle change that will lead to new positive health behaviors
B In 1990 the U.S. Department of Health and Human Services (USDHHS) issued a national report, Healthy People 2000, which outlined national health promotion and disease prevention objectives for people in the United States to be achieved by the year 2000. Nutrition was the key to these goals. This study was updated as Healthy People 2010. Healthy People 2010 challenged everyone—individuals, communities, and professionals—to take specific steps to ensure that good health and long life are enjoyed by all. In December 2010, USDHHS launched Healthy People 2020, which has four overarching goals:
1. Attain high-quality, longer lives free of preventable disease, disability, injury, and premature death
2. Achieve health equity, eliminate disparities, and improve the health of people in all groups
3. Create social and physical environments that promote good health for all
4. Promote quality of life, healthy development, and healthy behaviors across all life stages
DEFINITIONS COMMONLY USED IN NUTRITION
Absorption: the process by which end products of digestion are absorbed from the small intestine into circulation to be distributed to the cells
Anabolism: the process by which food molecules are built up into more complex chemical compounds
Basal metabolism: the energy required for the body to sustain life while in a resting state
Calorie: standard unit for measuring energy needed to raise the temperature of water by 1 ° C as the standard temperature
Catabolism: the breakdown of food molecules into carbon dioxide and water, which releases energy
Cellulose: a polysaccharide that makes up a framework of plants
Chemical digestion: action of enzymes that breaks large food molecules into smaller molecules
Cholesterol: a complex fat-related compound
Complementary proteins: foods that, when eaten together, supply the amino acid that is missing or in short supply in other food
Complete proteins: foods that contain all nine of the essential amino acids
Condensed: water removed and sugar added so carbohydrate content is increased
Conditionally indispensable amino acids: amino acids that the body can manufacture from other amino acids and that must be consumed in the diet under certain physiological conditions
Dietary fiber: the total amount of naturally occurring material in foods, mostly plants, that is not digested by the human digestive system and therefore is not absorbed
Digestion: the process of changing foods so they can be absorbed and used by cells
Dispensable amino acids: five amino acids that the body can manufacture from other amino acids
Enriched: the addition of nutrients to a food
Evaporated: heated above the boiling point so more than half of the water evaporates
Extracellular: all body fluids outside cells
Fortified: the replacement in food of nutrients lost during processing
Homeostasis: a condition in which the biological or physical body is not lacking any nutrients
Homogenized: fat particles evenly dispersed so cream does not separate
Hydrogenation: the process of adding hydrogen to a liquid or polyunsaturated fat and changing it to a solid or semisolid state
Hypervitaminosis: the excess of one or more vitamins
Incomplete proteins: foods that lack one or more of the essential amino acids
Indispensable amino acids: five amino acids that the body cannot manufacture from other amino acids
Intracellular: fluid within cells
Invisible fats: fats in which the fat is less obvious
Kilocalorie: the unit most often used in nutritional guidelines, equal to 1000 calories
Mechanical digestion: chewing, swallowing, peristalsis; breaks food into small pieces, mixes it with digestive juices, and moves it along the digestive tract
Monosaccharides: single sugars
Nutrients: chemical substances that are present in food and needed by the body to function
Nutrition: process by which the body uses food for growth, energy, and maintenance
Pasteurized: heated to a specific temperature to destroy pathogenic bacteria
Polysaccharides: complex carbohydrates
Precursor: substance that precedes and can be changed into an active vitamin
Saturated fats: organic compounds that are completely filled with all the hydrogen they can hold
Synthetic: manufactured vitamins
Unsaturated fats: hydrogen can be added to one or more places in a chemical structure
Visible fats: fats that are readily seen
Vitamins: organic compounds needed in small amounts for growth and maintenance of life
ABBREVIATIONS
EAR: estimated average requirement
HDL: high-density lipoprotein (good cholesterol)
LDL: low-density lipoprotein (bad cholesterol)
RDA: recommended dietary allowance
TPN: total parenteral nutrition
Type 1 diabetes mellitus (formerly called IDDM): insulin-dependent diabetes mellitus
Type 2 diabetes mellitus (formerly called NIDDM): non–insulin-dependent diabetes mellitus
PRINCIPLES OF NUTRITION
2. Builds and repairs body tissues
3. Regulates and controls the chemical processes in the body, which are essential for providing energy and building tissues
B Evidence of good nutrition (Table 4-1)
Table 4-1
Clinical Signs of Nutritional Status
| Features | Good | Poor |
| General appearance | Alert, responsive | Listless, apathetic; cachectic |
| Hair | Shiny, lustrous; healthy scalp | Stringy, dull, brittle, dry, depigmented |
| Neck glands | No enlargement | Thyroid enlarged |
| Skin, face, and neck | Smooth, slightly moist, good color, reddish-pink mucous membranes | Greasy, discolored, scaly |
| Eyes | Bright, clear; no fatigue circles | Dryness, signs of infection, increased vascularity, glassiness, thickened conjunctivae |
| Lips | Good color, moist | Dry, scaly, swollen, angular lesions (stomatitis), cheilosis |
| Tongue | Good pink color; surface papillae present; no lesions | Papillary atrophy, smooth appearance; swollen, red, beefy (glossitis) |
| Gums | Good pink color; no swelling or bleeding; firm | Marginal redness or swelling; receding, spongy |
| Teeth | Straight, no crowding; well-shaped jaw; clean, no discoloration | Unfilled cavities, absent teeth, worn surfaces; mottled, malpositioned |
| Skin, general | Smooth, slightly moist; good color; good turgor | Rough, dry, scaly, pale, pigmented, irritated; petechiae, bruises |
| Abdomen | Flat | Swollen |
| Legs, feet | No tenderness, weakness, swelling; good color | Edema, tender calf; tingling, weakness |
| Skeleton | No malformations | Bowlegs, knock-knees, chest deformity at diaphragm, beaded ribs, prominent scapulae |
| Weight | Normal for height, age, body build | Overweight or underweight |
| Posture | Erect, arms and legs straight, abdomen in, chest out | Sagging shoulders, sunken chest, humped back |
| Muscles | Well developed, firm | Flaccid, poor tone; undeveloped, tender |
| Nervous control | Good attention span for age; does not cry easily; not irritable or restless | Inattentive, irritable |
| GI function | Good appetite and digestion; normal, regular elimination | Anorexia, indigestion, constipation or diarrhea |
| General vitality | Endurance; energetic; sleeps well at night; vigorous | Easily fatigued; no energy; falls asleep in school; looks tired, apathetic |
Modified from Schlenker E, Long SL: Williams’ essentials of nutrition and diet therapy, ed 10, St Louis, 2011, Mosby.
C Primary causes of nutritional deficiency
1. Dietary lack of specific essential nutrients caused by:
a. Anorexia (resulting from a variety of causes).
b. Alcoholism (and the resulting lack of proper nutrition).
c. Poor food habits or eating nutritionally deficient foods.
2. Inability of the body to use a specific nutrient properly as a result of:
1. Nutrients are chemical substances that are present in food and needed by the body to function.
3. Individual nutrients have many specific metabolic functions. No nutrient ever works alone. In addition, the lack of one nutrient may inhibit the absorption or use of another nutrient.
1. Food habits are among the oldest and most deeply rooted aspects of many cultures. They are established early in childhood and can be difficult to change.
2. In many cultures foods take on significance in life events, including serious illness.
3. If possible, cultural preferences should be considered when any dietary modifications are planned.
4. In many instances religion will greatly influence nutritional practice (Table 4-2).
ASSIMILATION OF NUTRIENTS
Digestion and Absorption
A Digestion: the process of changing foods to be absorbed and used by cells; mechanical and chemical digestion occur simultaneously.
1. Mechanical digestion (chewing, swallowing, peristalsis) breaks food into small pieces, mixes it with digestive juices, and moves it along the digestive tract.
2. Chemical digestion occurs through the action of enzymes, which break large food molecules into smaller molecules.
a. Carbohydrate digestion begins in the mouth and occurs primarily in the small intestine; carbohydrates are reduced to simple sugars (monosaccharides) such as glucose for absorption. Sorbitol, a naturally occurring sugar that is not absorbed, may cause diarrhea in children.
b. Protein digestion begins in the stomach and is completed in the small intestine; proteins are broken down into amino acids for absorption.
c. Fat digestion begins in the stomach but occurs primarily in the small intestine; fats are reduced to fatty acids and glycerol for absorption.
B Absorption: the process by which end products of digestion (fatty acids, glycerol, amino acids, glucose) are absorbed from the small intestine into circulation (blood and lymph) to be distributed to the cells. Vitamins may require proper pH to be absorbed. Patients with achlorhydria may develop vitamin B12 deficiency. Certain foods or beverages such as grapefruit juice can alter the metabolism or absorption of medications.
Metabolism
A Use of food by the body cells for producing energy and building complex chemical compounds
1. Catabolism: the breakdown of food molecules into carbon dioxide and water, which releases energy; carbohydrates are primarily catabolized for energy.
2. Anabolism: the process by which food molecules are built up into more complex chemical compounds; proteins are primarily anabolized (used for building).
Energy
A Energy is required for the metabolic processes of catabolism and anabolism; energy needs of the body are based on three factors.
1. Physical activity: the type of activity and how long it is performed
2. Basal metabolism: the energy required for the body to sustain life while in a resting state (1 calorie per kilogram of body weight per hour)
3. Thermal effects of food: energy required for the digestion, absorption, and metabolism of foods
Drugs and Nutrition
A Drugs affect taste, appetite, intestinal motility, absorption, metabolism, and excretion of nutrients and cause nausea and vomiting. Many of these interactions may compromise nutritional status and health.
B If a nutrient binds with a medication, decreased solubility of both the nutrient and the drug can result. Interactions between certain foods and certain medications may alter the amount of drug that is available to the body. Foods or beverages containing alcohol can trigger a reaction in a patient taking disulfiram (Antabuse), a treatment for alcoholism.
C People at greatest risk of undesirable drug-nutrient interaction are those taking medication for long periods, those taking two or more medications, and those not eating well. Elderly people fall into the high-risk category.
D Certain medications may cause weight gain through retained fluid or increased appetite.
NUTRIENTS
Carbohydrates
1. Monosaccharides: single sugars, which require no digestion and are easily absorbed into the bloodstream (e.g., glucose, fructose, galactose)
2. Disaccharides: double sugars, which must be broken down before absorption (e.g., sucrose [table sugar], lactose, maltose)
3. Polysaccharides: complex carbohydrates composed of many sugar units (e.g., starches, glycogen, dietary fiber)
1. Provide energy (glucose is the only form of energy that can be used by the central nervous system)
2. Protein-sparing effect (allows protein to be used for tissue building rather than energy production)
3. Essential for complete metabolism of fats (incomplete fat metabolism leads to buildup of ketones and acidosis)
1. Polysaccharides (complex carbohydrates): bread, cereal, pasta, rice, corn, baked goods
2. Disaccharides (double sugars): table sugar, sugar cane, molasses
3. Monosaccharides (simple carbohydrates): fruit, honey, milk
1. Carbohydrate digestion occurs primarily in the small intestine and is acted on by three enzymes: sucrase, lactase, and maltase. Gas in the intestinal tract is largely a result of incomplete digestion of carbohydrates.
2. Carbohydrates must be broken down into monosaccharides before being absorbed.
3. Monosaccharides are carried to the liver, where glucose is released to the cells.
4. Excess glucose is stored as glycogen to be used when needed or converted to fat and stored as fat tissue.
5. Insulin regulates the use of glucose for use by the cells, thereby lowering blood sugar.
6. The hormone glucagon regulates the conversion of glycogen back to glucose, causing an increase in blood glucose.
7. The speed with which food raises the blood glucose is the glycemic index.
8. Hypoglycemia in people who do not have diabetes can be managed with small feedings approximately every 3 hours from a diet that is low in sugar and high in fiber.
E Excess carbohydrates in diet may lead to:
2. Tooth decay and gum disease.
3. Malnutrition (if empty-calorie foods such as candy and soft drinks are consumed extensively).
1. The greater portion of carbohydrates should come from starches, and the least from simple sugars (which provide empty calories).
2. Encourage the intake of whole-grain bread and cereal products; if refined cereal products are used, they should be enriched.
1. Definition: the total amount of naturally occurring material in foods, mostly plants, that is not digested by the human digestive system and therefore is not absorbed. Adequate amounts are needed to facilitate proper bowel movements and reduce serum cholesterol and blood glucose levels and the risk of cancer.
2. There are two categories of dietary fiber: soluble and insoluble, based on the solubility in water.
Protein
1. Essential amino acids: amino acids that the body cannot manufacture in sufficient quantity, or at all, and that therefore must be supplied in the diet. There are nine (essential) amino acids.
2. Nonessential amino acids: amino acids that the body can manufacture from other amino acids; therefore they are not necessary in the diet.
3. Conditional amino acids: amino acids that are usually not essential, except in times of illness and stress.
1. Build and repair body tissue (primary function)
2. Furnish energy if carbohydrate or fat is insufficient for this purpose
3. Maintain normal circulation of tissue and blood vessel fluids through the action of plasma protein
4. Aid metabolic functions by combining with iron to form hemoglobin; used to manufacture enzymes and hormones
5. Aid body defenses by manufacturing lymphocytes and antibodies
1. Digestion of protein begins in the stomach, where it is acted on by the enzyme pepsin. Digestion is completed in the small intestine by three enzymes: trypsin, chymotrypsin, and carboxypeptidase.
2. Protein must be broken down into amino acids to be absorbed and distributed to the cells. Accumulation of uric acid, a byproduct of purine catabolism, can cause gout. High intake of animal protein is associated with kidney stones.
3. End products of protein metabolism are hydrogen, oxygen, nitrogen, water, uric acid, and urea.
4. Dietary deficiencies of B-complex vitamins may cause elevated levels of homocysteine, an amino acid product linked to vascular disease in coronary and renal blood vessels.
1. Complete proteins: foods that contain all nine essential amino acids in amounts capable of meeting human requirements (mainly animal sources such as meats, fish, poultry, eggs, milk, cheese)
2. Incomplete proteins: foods that lack one or more of the essential amino acids (mainly plant sources such as cereal grains, nuts, legumes, lentils)
3. Complementary proteins: foods that, when eaten together, supply the amino acid that is missing or in short supply in the other food (e.g., peanut butter with bread, beans with rice, baked beans with brown bread). A rule of thumb is that a grain and a legume eaten together supply all the essential amino acids.
1. To build a healthier plate, dietary guidelines recommend varying one’s protein food choices.
2. Dietary proteins are not stored in the body as amino acids. Proteins are the main components needed to build and repair body tissues. If the right amount and types are not available, the nitrogen is broken off, and the remainder of the protein is used for energy or stored as fat. The need for cell building and maintenance is continuous. For a supply of proteins to be available on a regular basis, a source of complete proteins should be eaten at every meal.
3. Increased protein is necessary during periods of growth, illness, injury, or stress; after surgery; and when bed rest is prescribed (especially for older adults). Protein supplements such as creatine may not enhance growth or endurance, despite marketers’ claims.
4. Kwashiorkor, a protein-deficiency disease, is seen in many underdeveloped countries.
5. Marasmus is overt starvation caused by a deficiency of calories from any source.
6. Leptin and other hormones secreted by adipose tissue act on the brain to control appetite.
Fats (Lipids)
1. Supply energy for body activities when carbohydrates are not available. All body tissues except brain and nervous cells can use fat for energy. Most concentrated form of energy yields 9 calories/g.
2. Act as insulation to maintain body temperature and protect organs from mechanical injury
3. Carry fat-soluble vitamins A, D, E, and K and aid in their absorption
4. Provide a feeling of fullness and satisfaction after eating because of their slow rate of digestion
5. Furnish the essential fatty acid linoleic acid, which is found primarily in vegetable oils; called essential because they cannot be synthesized in the body and are vital to body functioning
6. Omega-3 fatty acids (polyunsaturated fat), which are found in fatty fish, may contribute to lower risks of heart disease.
1. Saturated fats: The chemical structure is completely filled with all the hydrogen it can hold. They are usually from animal sources and solid at room temperature (e.g., fats in meat, dairy products, eggs; coconut oil, palm oil, and chocolate are also highly saturated). Trans fatty acids (TFAs) tend to raise low-density lipoprotein (LDL) (“bad”) cholesterol and lower high-density lipoprotein (HDL) (“good”) cholesterol when used instead of fatty acids or natural oils.
2. Unsaturated fats: The chemical structure has one or more places where hydrogen can be added. They are less dense, are usually liquid at room temperature (with the exception of margarine), and are chiefly from plant sources (e.g., vegetable oils such as cottonseed, soybean, corn oil).
a. Monounsaturated fats have one place for hydrogen to be added.
b. Polyunsaturated fats have two or more places for hydrogen to be added.
c. Hydrogenation is the process of adding hydrogen to a liquid or polyunsaturated fat and changing it to a solid or semisolid state (however, hydrogenation reduces the polyunsaturated fat content and therefore possibly reduces its health value).
d. Triglycerides are fats eaten in foods or made in the body from other sources such as carbohydrates. Excess calories consumed in a meal are converted and transported to fat cells for storage.
1. Digestion of fat begins in the stomach, where gastric lipase acts on emulsified fats.
2. Major portions of fat digestion occur in the small intestine, where bile emulsifies fats (breaks it into small droplets); pancreatic lipase changes the emulsified fats into fatty acids and glycerol, the end products of fat digestion.
3. Fats are carried as lipoproteins to body cells, where they are either broken down for use as energy or stored as adipose tissue.
1. Visible fats: those readily seen (e.g., butter and margarine, salad oils, shortening, fat in meats)
2. Invisible fats: those in which the fat is less obvious (e.g., milk, avocado, cheese, lean meat)
E Cholesterol: a complex fat-related compound
1. A normal component of blood and of all body cells, especially brain and nerve tissue
2. Necessary for normal body functioning as structural material in cells, in the production of vitamin D, and in the production of a large number of hormones
3. Supplied by food (mainly animal sources). Some are synthesized within the body, mainly in the intestinal walls and liver, in response to need. Excess calories consumed are converted into triglycerides for storage as fat.
4. A variety of factors, including diet, heredity, emotional stress, and exercise, affect blood cholesterol levels. Saturated fats tend to raise blood cholesterol, whereas polyunsaturated fats are recommended for lowering cholesterol levels.
5. Cholesterol is carried to and from body cells by special carriers called lipoproteins.
a. HDL, or “good” cholesterol, carries cholesterol away from the arteries and back to the liver for removal from the body.
b. LDL, or “bad” cholesterol, tends to circulate in the bloodstream and form plaque on the inner walls of arteries.
6. Risk is classified according to total cholesterol level as follows:
7. If the total cholesterol level is borderline high or high, the levels and ratio of LDL and HDL should be evaluated.
8. High cholesterol levels predispose individuals to atherosclerosis, the underlying pathological factor of coronary heart disease, and other serious health problems.
9. Foods high in cholesterol are organ meats, animal fat, egg yolk, and shellfish.
1. The Dietary Guidelines for Americans 2010 ChooseMyPlate illustrates the five food groups that are the building blocks for a healthy diet through use of a familiar image—a place setting for a meal. Before you eat, think about what goes on your plate or in your cup or bowl. Further recommendations are to eat fewer foods that are high in solid fats.
G Effects of excess fat intake
Vitamins
Table 4-3
1. Vitamins: organic compounds needed in small amounts for growth and maintenance of life
2. Precursor (or provitamin): substance that precedes and can be changed into an active vitamin (e.g., carotene is the precursor of vitamin A)
3. Hypervitaminosis: the excess of one or more vitamins
4. Synthetic: manufactured vitamins
5. Enriched: the addition of nutrients to a food, often in amounts larger than might be found naturally in that food
6. Fortified: the replacement in food of nutrients lost during processing
2. Essential to life because they generally cannot be synthesized by the body and are necessary for cell metabolism
3. Functions include tissue building and regulation of body functions.
4. Needed in minute amounts (milligrams [mg] or micrograms [mcg]); the safety of taking megadoses is debatable.
5. Well-balanced diet should provide adequate vitamins to fulfill body requirements.
C Classified on basis of solubility
1. Fat-soluble vitamins: A, D, E, K
a. Sufficient fats needed in diet to carry fat-soluble vitamins
b. Stored in body so deficiencies are slow to appear
c. Absorbed in the same manner as are fats. Thus anything that interferes with absorption of fats interferes with absorption of fat-soluble vitamins (e.g., mineral oil, an indigestible substance, carries fat-soluble vitamins with it out of the body).
2. Water-soluble vitamins: C and B complex
Special Vitamin Considerations
A Current research indicates that the effects of megadoses of vitamin C on the common cold are minimal.
B Effects of vitamin C on cancer still require further study.
C Claims list vitamin E as a “cure-all,” especially in prolonging virility in men, preventing miscarriages, and curing muscular weakness.
D Current research has not established the validity of these claims; however, the amounts usually taken in supplements have caused no damage.
Minerals
A Definition: inorganic elements essential for growth and normal functioning (Table 4-4)
1. Major minerals, or macrominerals, are found in the largest amounts in the body and are needed in large amounts (100 mg or more per day); they are calcium, phosphorus, potassium, sodium, chlorine, magnesium, and sulfur.
2. Microminerals, or trace elements, are needed in small amounts; examples include iron, zinc, copper, iodine.
1. Found in all body tissues and fluids
2. Occur naturally in foods (especially unrefined foods)
3. Do not furnish energy but regulate body processes that furnish energy
1. Constitute bones and teeth (calcium, phosphorus)
2. Transmit nerve impulses and aid in muscle contraction
3. Control water balance (sodium, potassium)
5. Synthesize essential body compounds (e.g., iodine for thyroxine)
6. Act as catalysts for tissue reactions (e.g., calcium needed for blood clotting)
Water
A Water makes up 50% to 65% of the weight of an average adult.
1. Intracellular: fluid within cells composed of water plus concentrations of potassium and phosphates; contains minerals, potassium, magnesium, and phosphorus
2. Extracellular: all body fluids outside cells, including interstitial fluid, plasma, and watery components of body organs and substances; contains minerals and sodium chloride
1. Essential component of all tissues and fluids
2. Transportation of nutrients from the digestive tract to the bloodstream and from cell to cell; removal of waste products from cells to outside the body
4. Maintenance of stable body temperature (as temperature increases, sweating occurs, evaporates, and cools the body)
C Overall water balance in the body
1. Intake: Under ordinary conditions adults need 2 to 3 L of liquid per day—five or six glasses of which should be water.
a. Ingested fluids such as water, soups, and beverages
b. Water in foods that are eaten
c. Water formed from cell oxidation (when nutrients are burned)
2. Output: averages 2600 mL daily
D Additional fluids are required:
Cellulose
A Definition: a polysaccharide that makes up the framework of plants; provides bulk (fiber or roughage) for the diet; cannot be broken down by the human digestive system and therefore is not absorbed
B Function: to absorb water, provide bulk, and stimulate peristalsis
C Found in the stalks and leaves of plants, the skins of fruit and vegetables, and the outer covering of seeds and cereals (refined cereals have most of the fiber removed and provide little bulk)
NUTRITIONAL GUIDELINES
DIETARY REFERENCE INTAKES
A Developed by the Food and Nutrition Board of the National Academy of Sciences, this revised the recommended dietary allowances (RDAs)
B Four types of Dietary Reference Intake (DRI) reference values
C Primary goals are to prevent nutrient deficiencies and reduce the risk of chronic diseases such as osteoporosis, cancer, and cardiovascular disease.
U.S. DIETARY GOALS OR DIETARY GUIDELINES
A Developed by the U.S. Department of Agriculture and USDHHS
B Established in 1980 and updated every 5 years; the current Nutrition and Your Health: Dietary Guidelines for Americans 2010 was released January 2011. These guidelines emphasize three major goals for Americans. They are:
1. Balance calories with physical activity to manage weight.
2. Consume more of certain foods and nutrients such as fruits, vegetables, whole grains, fat-free and low-fat dairy products, and seafood.
3. Consume fewer foods with sodium (salt), saturated fats, trans fats, cholesterol, added sugars, and refined grains.
C The 2010 Dietary Guidelines for Americans include 23 key recommendations for the general population and six additional key recommendations for specific population groups, such as pregnant women. The recommendations are intended to help people choose an overall healthy diet.
Nutritional Labeling and Education Act of 1990
A This regulation has increased consumer access to safe products and knowledge of what nutrients are in food.
B The nutrition facts panel must include the serving size, calories (and calories from fat), and nutrients (i.e., how much of each nutrient and the percent daily value [%DV]).
C Ingredients labeled GRAS are “generally recognized as safe” for ingestion by anyone. See www.fda.gov/Food/FoodIngredientsPackaging/GenerallyRecognizedasSafeGRAS/default.htm for listing.
Nutritional Assessment
A Two phases: screening and assessment. The purpose is to screen for nutritional risks and apply specific assessment techniques to determine an action plan.
B Components of nutritional assessment: anthropometric measurements (e.g., body mass index), biochemical tests, clinical observations, dietary and personal histories. Techniques such as hair analysis have not been demonstrated to provide useful information about nutritional status. All components work together to allow determination of the best action plan for the individual in the healthy and sick populations within the context of the individual’s personal, social, and economic background. Techniques such as the “energy panel” can be used to determine if nutritional status is adequate to support an active immune system.
ChooseMyPlate
Originally identified in the Child Obesity Task Force report, which noted that simple, actionable advice for consumers is needed, MyPlate replaces the MyPyramid image as the government’s primary food group symbol as an easy-to-understand visual cue to help consumers adopt healthy eating habits consistent with the 2010 Dietary Guidelines for Americans. MyPyramid will remain available to interested health professionals and nutrition educators in a special section of the new website (www.choosemyplate.gov). See Figure 4-1. Note: ChooseMyPlate illustrates the five food groups that are the building blocks for a healthy diet using a familiar image—a place setting for a meal. Before you eat, think about what goes on your plate or in your cup or bowl. The following are the guideline messages:
D ChooseMyPlate provides a list of 10 tips for a great plate.
1. Balance calories—Find out how many calories you need for a day as a first step in managing your weight.
2. Enjoy your food but eat less—Eating elsewhere may lead to eating too many calories. Pay attention to hunger and fullness cues before, during, and after meals. Use them to recognize when to eat and when you’ve had enough.
3. Avoid oversized portions—Use a smaller plate, bowl, and glass.
4. Food to eat more often—Eat more vegetables, fruits, whole grains, and fat-free or 1% milk and dairy products.
5. Make half your plate fruits and vegetables—Choose red, orange, and dark-green vegetables like tomatoes, sweet potatoes, and broccoli, along with other vegetables for your meals. Add fruit to meals as part of main or side dishes or as dessert.
6. Switch to fat-free or low-fat milk—They have the same amount of calcium and other essential nutrients as whole milk, but fewer calories and less saturated fat.
7. Make half your grains whole grains—To eat more whole grains, substitute a whole-grain product for a refined product, such as eating whole wheat bread instead of white bread or trying brown rice instead of white rice.
8. Foods to eat less often—Cut back on foods high in solid fats, added sugars, and salt.
9. Compare sodium in foods—Use the Nutrition Facts label to choose lower-sodium versions of foods like soup, bread, and frozen meals. Select canned foods labeled “low sodium,” “reduced sodium,” or “no salt added.”
10. Drink water instead of sugary drinks—Cut calories by drinking water or unsweetened beverages.
FOOD MANAGEMENT
FOOD FADS AND FACTS: MEAT EATERS VERSUS VEGETARIANS
A Problems occur when too large a portion of the diet consists of meat.
1. Excess calories tend to be consumed. Meat (and the fat therein) is high in calories. Because of the taste, the tendency is to eat more than is required.
2. When a large portion of the meal is meat, a smaller portion of fruits and vegetables is consumed; therefore less fiber and fewer of the nutrients in fruits and vegetables are consumed.
B Vegetarians also can have nutritional deficiencies.
1. Calories may be insufficient despite consumption of large amounts of foods.
2. Protein can be lacking; incomplete protein must be supplemented with complementary proteins.
3. Strict vegetarians may need supplements of cobalamin (vitamin B12) because it is found only in animal proteins.
C The ideal diet combines both types of diet with a variety of foods.
ECONOMIC CONSIDERATIONS IN MENU PLANNING
1. Take advantage of specials and sales to plan balanced meals.
2. Shop from a list to avoid impulse buying.
3. Supplemental food may be available from programs such as the Women, Infants, and Children (WIC) program or Meals on Wheels.
1. Buy foods in season and in good supply.
2. Buy in quantity if adequate storage is available (larger quantities may cost less per unit).
3. Buy sale items only if they can be used.
4. Use unit pricing to find the best buys among brands.
5. Know grades and brands of foods. Grading of canned goods has no bearing on nutritive value. Generic labeling can save up to 25% of name-brand items.
6. Purchase staple and canned goods when on sale.
7. Remember that cost per serving rather than per pound is important, especially in buying meat.
8. Compare labels for weights and ingredients.
9. Buy less expensive forms of food (margarine is less expensive than butter).
10. Limit purchase of empty-calorie foods.
11. Decrease the cost of protein in the diet by using small amounts of meats, fish, and poultry and lower grades and less expensive cuts of meat; legumes, peanut butter, eggs, and cheese are good sources of less expensive protein.
12. Try to avoid convenience foods (any food bought partially prepared and ready to eat with little home preparation); they are usually more expensive than foods prepared entirely at home and less nutritionally balanced, containing high proportions of fat, calories, and sodium.
C Care for foods after purchase.
STORAGE AND PREPARATION OF BASIC FOODS
1. Store milk refrigerated in covered container; powdered milk should be stored in a cool, dry place; refrigerate powdered milk after reconstituting.
1. Refrigerate well, wrapped or in tight containers.
2. It is most palatable if served at room temperature; cook at low temperatures for a short time.
1. Refrigerate promptly; avoid purchase of eggs that are already cracked (eggs that are cracked later should be used only in foods that will be well cooked).
2. Cook at lower temperatures to prevent discoloration, curdling, or toughness.
1. Store in cool, dry place; bread retains freshness best at room temperature but molds faster; it freezes well.
2. Cook cereals according to directions; overcooking reduces vitamin content.
1. Store in refrigerator for a short time or freeze for longer storage.
2. Less expensive meats, although nutritionally equivalent to more expensive ones, require longer cooking at lower temperatures.
TYPES OF MILK
A Skim: fat and vitamin A removed (may have vitamins A and D added); contains all other nutrients of whole milk
B Homogenized: fat particles evenly dispersed so cream does not separate
C Pasteurized: heated to a specific temperature to destroy pathogenic bacteria (but nutrients are not affected)
D Condensed: water removed and sugar added so carbohydrate content is increased; low in calcium and vitamins and high in sugar compared with whole milk
E Evaporated: heated above the boiling point so more than one half of the water evaporates
F Low fat: contains 0.5% to 2% fat; lower in calories than whole milk but comparable in nutrient value
G Powdered or dry: water removed; least expensive form of milk on the market; when reconstituted has the same nutrient value as the milk from which it was made.
COMMON TYPES OF FOOD POISONING
STAPHYLOCOCCAL FOOD POISONING
A Caused by Staphylococcus aureus bacteria; resistant to heat
B Involves foods such as custard; potato, macaroni, egg, and chicken salads; cheese; ham; and salami
C Exhibited by symptoms such as abdominal cramps, diarrhea, and vomiting; lasts 1 to 2 days; usually mild and attributed to other causes
D Prevented by keeping foods above 140 ° F (60 ° C) or below 40 ° F (4 ° C); toxin is destroyed by boiling for several hours or heating in a pressure cooker at 240 ° F (138.5 ° C) for 30 minutes.
CLOSTRIDIAL FOOD POISONING
A Perfringens poisoning – the most common causative agent of gas gangrene
1. Caused by Clostridium perfringens, spore-forming bacteria that grow in the absence of oxygen
2. Involves foods such as stews, soups, and gravies made from poultry and red meat
3. Exhibited by symptoms such as nausea without vomiting, diarrhea, and acute inflammation of the stomach and intestine; usually lasts 1 day
4. Prevented by storing foods properly and keeping foods above 140 ° F (60 ° C) or below 40 ° F (4 ° C)
1. Caused by Clostridium botulinum, spore-forming bacteria that grow and produce toxins in absence of oxygen (anaerobic)
2. Involves canned low-acid foods, especially home-canned foods such as meats, corn, peas, green beans, asparagus, and mushrooms
3. Exhibited by symptoms such as inability to swallow, double vision, and progressive respiratory paralysis; fatality rate high if condition is untreated.
4. Prevented by pressure cooking canned foods for specified length of time; any can or jar with a bulging top should be discarded.
SALMONELLOSIS
A Caused by salmonellae, bacteria widespread in nature that live in the intestinal tracts of humans and animals; transmitted by eating infected food or by contact with people who are infected or are carriers of the disease; also transmitted by insects or rodents
B Involves poultry, red meats, dairy products, and eggs
C Exhibited by symptoms such as severe headache, vomiting, diarrhea, abdominal cramps, and fever; usually last 2 to 7 days
D Prevented by heating foods at 140 ° F (60 ° C) for 10 minutes or at higher temperatures for less time
ESCHERICHIA COLI INFECTION
A Caused by pathogenic E. coli; some types are normally found in human intestinal system
B Pathogenic E. coli found in raw ground beef
C Bacterium attacks intestinal wall and spreads to body.
D Exhibited by symptoms such as bloody diarrhea, cramps, fever, chills, dehydration, kidney problems; can be fatal
E Prevented by using well-cooked meats and sanitary food handling
NUTRITION THROUGHOUT THE LIFE CYCLE
INFANT NUTRITION
A Infants require more protein and calories per pound of body weight than adults do because infants have more body surface in proportion to weight and because of their growth and activity.
B Breast-feeding is the recommended method of feeding, if possible. More vitamin C is provided, and protein and sugar are more easily digested than those in cow’s milk. The infant is also provided with antibodies against disease, and breast-feeding assists in establishing the mother-child bond. In addition, breastfed babies have fewer allergies and intolerances and easier digestion.
C Bottle-feeding is an acceptable alternative if close mother-child contact is maintained. Most mothers use a commercially prepared formula such as Enfamil; a soy-based product such as Isomil can be used if the infant is allergic to milk products. At no time during the first year of life should an infant be fed regular whole cow’s milk. Concentration of cow’s milk may cause gastrointestinal (GI) bleeding or renal discomfort. Skim milk or low-fat milk provides infants with too little energy and linoleic acid.
D The American Academy of Pediatrics recommends breast milk supplemented by vitamin D and fluoride from birth and iron supplements after 4 months of age.
E Introduction of solid foods varies among pediatricians, with most favoring a delay until the infant is at least 6 months of age.
1. Infant cereal is usually given first (often with added iron to supplement a possible lack in the infant’s diet; prenatal iron reserves last 5 to 6 months). Rice cereal is given first because it is easy to digest and provokes few allergies.
2. Fruits, vegetables, and egg yolk are frequently given next. (Because of possible allergic reactions, egg white is delayed until late in the first year.)
3. Solid foods should be introduced one at a time and at 4- to 5-day intervals to observe for any allergic reactions.
4. Adding sugar or salt to an infant’s food is undesirable.
5. Infants can choke on small foods such as berries, corn, popcorn, hot dogs, or candy.
6. Infants should not eat honey because it contains botulism spores, which can harm the infant (even though quantities are too low to harm older children and adults).
PRESCHOOL CHILDREN
A Growth rate is slower and more erratic, and food intake varies accordingly.
B A variety of foods should be offered.
1. Finger foods such as carrot sticks are enjoyed.
2. Serve small amounts because too large a serving can discourage a child from eating.
4. Do not coax a child to eat; if a food is refused, offer it at a later time.
5. Nutritious snacks are a viable alternative for a child who is a poor eater.
C Teach healthy eating habits; avoid rewarding good behavior with food.
SCHOOL CHILDREN (5 TO 10 YEARS OF AGE)
A Growth increase is gradual at this age (approximately equal for boys and girls).
B Proper nutrition is important for proper mental and physical development; an adequate breakfast is important for alertness during class.
C Children are usually good eaters at this age and should be encouraged by the examples set at home and at school. Promote healthy eating.
ADOLESCENTS
A Tremendous growth spurt occurs at puberty (age of sexual maturity).
B Diets are influenced by peers, with many empty-calorie foods being consumed. Adolescents tend to skip lunch. Eating disorders such as anorexia or bulimia may develop with impaired self-esteem issues.
C Boys gain mostly lean muscle tissue; they consume large amounts of food to meet energy requirements.
D Girls gain more fat tissue; their diets may be more influenced by a desire to remain thin; girls frequently require iron supplements to meet their needs; adequate nutrition during adolescence helps avoid complications during pregnancy. Promote healthy eating along with exercise.
ADULTS
A Adequate nutrition throughout the life span is important for avoiding many serious illnesses.
B Proper nutrition is based on guidelines set by U.S. government agencies (e.g., ChooseMyPlate).
C Persons who consume a balanced diet usually do not need vitamin supplements.
D If a woman of childbearing age is a smoker and has poor dietary intake, a vitamin C supplement of 100 mg/day is recommended.
OLDER ADULTS
A Physiological changes affect nutrition of older adults.
1. Aging slows the basal metabolic rate (BMR); combined with decreased activity, the result is decreased energy requirements and decreased number of calories needed.
2. Taste may be adversely affected by gradual diminishing of the senses of smell, sight, and taste.
3. Loss of teeth may affect proper chewing, food intake, or enjoyment. Older adults, children, and psychiatric patients may “pouch” or “cheek” foods or medications and should be checked to make sure that intake is indeed swallowed.
4. Reduced saliva makes swallowing more difficult and digestion less efficient.
5. Decreased movement of wastes through intestines contributes to constipation.
6. Marginal deficiencies of ascorbic acid, thiamine, and riboflavin have occurred in some elderly patients.
7. Decrease in absorption and use of nutrients results from decreased digestive juices and gastric motility reduction.
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