Y khoa, dược - Nutrition and special diets

49Nutrition and Special Diets49-2Learning Outcomes49.1 Describe how the body uses food.49.2 Explain the role of calories in the diet.49.3 Identify nutrients and their role in health.49.4 Recall the Dietary Guidelines for Americans.49-3Learning Outcomes (cont.)49.5 Explain how the Food Guide Pyramid can be used to plan a nutritious, well-balanced diet and healthy lifestyle.49.6 Describe the test used to assess body fat.49.7 Explain reasons why a diet may be modified.49.8 Identify types of patients who require special diets and the modifications required for each.49-4Learning Outcomes (cont.)49.9 Describe the warning signs, symptoms, and treatment for eating disorders.49.10 Educate patients about nutritional requirements. 49.11 Document patient education about nutrition.49-5IntroductionNutrition How the body takes in and utilizes food and nutrientsFive-part processIntake DigestionAbsorptionMetabolismElimination Medical assistant – understand relationship between nutrition and health49-6Daily Energy RequirementsThe body requires nutrients To provide energyTo build, repair, and maintain body tissuesTo regulate body processes49-7MetabolismThe sum of all cellular processes that build, maintain and supply energy to living tissuePhasesAnabolism – nutrients are changed into more complex substances that are used to build body tissuesCatabolism – complex substances are broken down into simpler substances and converted to energyMetabolism affected by age, weight, activity, state of health, and other factors49-8CaloriesKilocalorie (calorie) Measurement of energy produced by food Amount of energy needed to raise the temperature of 1 kg of water by 1°C.Used to measure the energy expended during activities and metabolic processesExcess calories stored as fatCount calories of food eaten and estimate expenditure for activities49-9Apply Your KnowledgeWhat is the role of diet in health?ANSWER: Food is the source of nutrients the body needs to function properly. Sometimes a special diet is needed to stay healthy or regain health, and some conditions require special diets.What is the difference between anabolism and catabolism? ANSWER: Anabolism converts nutrients into complex substances needed to build body tissues. Catabolism converts complex substances into simpler forms and converts them into energy.Correct!49-10NutrientsNeeded for EnergyGrowthRepairBasic processesEnergy is only provided byProteinsCarbohydratesFats Nutrients are provided byProteinsCarbohydratesFiberLipidsVitaminsMineralsWater49-11ProteinsFunctions Building and repairing cells and tissuesMaintaining water balanceAntibody production and disease resistanceMaintaining body heat10% to 20% of total caloric intake daily1 gm = 4 caloriesDeficiency Weight loss/fatigueMalnutritionLower resistance to infectionInterference with normal growth processes49-12Proteins (cont.)Complete proteinsContain all 9 essential amino acidsAnimal food sourcesRecommend lean meats, low-fat or skim milkIncomplete proteinsLack one or more essential amino acidsPlant sourcesCan be combined to provide all 9 essential amino acids49-13CarbohydratesFunctionsProvide 2/3 of daily energy needsProvide heatMetabolize fatsPreserve protein for uses other than energy production50% to 60% of total caloric intake daily1 gm = 4 caloriesDeficiency Weight lossProtein lossFatigue Excess contributes to fat stores49-14Carbohydrates (cont.)Complex carbohydratesPolysaccharides – long chains of sugar unitsTypes Starch – major source of energyFiberSimple sugarsFruits and some vegetablesMilkTable sugarExcess Stored in liver and muscles cells as glycogenConverted into and stored as fat49-15FiberDoes not supply energy or heatFunctionsIncreases and softens the bulk of stoolAbsorbs wastes and toxinsDecreases the rate of carbohydrate breakdown and absorption20 – 30 gm per day for adultsTypesSoluble Absorbs fluid and swells when eatenSlows absorption Helps control blood glucoseLowers cholesterolInsoluble – promotes regular bowel movements49-16LipidsConcentrated source of energy 1 gm = 9 caloriesTriglycerides Simple lipids 95% of dietary lipids Cholesterol Compound lipids5% of dietary lipidsFunctionsProvide a concentrated source of energyTransport fat-soluble vitaminsStore energy as body fat – insulate and protect organsProvide a feeling of fullness49-17Lipids (cont.)Saturated fatsPrimarily from animal sourcesSolid at room temperatureTrans fats Formed during hydrogenation of vegetable oilsFDA recommends zero consumptionUnsaturated fatsLiquid at room temperatureTypes PolyunsaturatedMonounsaturated 49-18Lipids (cont.)Lipid levelsHigh cholesterol Heart disease/stroke Peripheral vascular diseaseLipoproteins Carry lipids through the bloodstreamLow-density (LDL)High-density (HDL)Cholesterol Fat-related substance produced by liverAnimal-based food sourcesEssential to healthPart of cell membranesStructural basis for steroid hormones and vitamin DComponent of bile49-19ECVitaminsOrganic substances Essential for normal growth and maintenance Essential for resistance to infectionHelp the body use other nutrientsAssist with body processesAbsorbed through digestive tractTypes Water soluble – not stored by the bodyFat-soluble – stored by the bodyWell-balanced diet usually minimizes likelihood of vitamin deficiencyAB12B6D49-20MineralsNatural, inorganic substancesBuild and maintain tissuesCarry out life functionsMajor minerals – needed in large quantitiesTrace minerals – needed in small amounts Absorbed in intestinesEstablished RDAsCalcium  Zinc Iodine  Iron Magnesium  Phosphorus Selenium 49-21WaterNo caloric value65% of body weightFunctionsMaintains fluid balanceLubricates moving partsDissolves chemicals and nutrientsAids in digestionTransports nutrients and secretionsFlushes out wastesRegulates body temperature49-22Water (cont.)Fluid balance – intake should equal outputPatient educationExplain the importance of waterList sources of water49-23Principal Electrolytes and Nutrients of Special InterestElectrolytesSodium Fluid and acid-base balanceMaintains normal conditions inside and outside of cellsPotassiumMuscle contractionFluid and electrolyte balanceChlorideFluid and electrolyte balanceComponent of hydrochloric acidAntioxidants – chemical agents that neutralize free radicals (by-products of normal metabolism)49-24Apply Your KnowledgeMatching:___ Bulk to stool A. Cholesterol___ Tissue repair B. Antioxidants___ Excess stored as glycogen or fat C. Proteins___ Concentrated source of energy D. Water___ Produced by liver E. Trans fats___ No caloric value F. Fiber___ Neutralizes free radicals G. Lipids___ Formed during hydrogenation H. CarbohydratesANSWER:HGFEDCBASUPERJOB!49-25Dietary GuidelinesEstablished to help peopleGet proper nutritionReduce occurrence of diseaseControl weightDesigned to encourage healthy eating habitsSuggest types and quantities of foods49-26USDA and U.S. Dept. of Health and Human Services Dietary GuidelinesRecommendationsAdequate nutritional intakeHealthy body weightRegular physical exerciseIncrease fruits, low-fat dairy, and whole-grainsLimit fatsLimit alcoholFood safetyDisinfect food surfaces Wash handsCook foods to safe temperatureRefrigerate foods Avoid raw eggs and meats and unpasteurized milk or juices49-27USDA Food Guide PyramidRevised in 2005Emphasizes fruits, vegetables, whole grains, beans, and nutsLess emphasis on carbohydratesHelps balance nutritional needs with physical activity needsColor codedOrange – grainsGreen – vegetables Red – fruitsYellow – oilsBlue – milk productsPurple – meats/beansAction figure – physical activity Food Pyramid49-28BackGrainsFruitsOilsMilk ProductsPhysical ActivityMeat/BeansVegetables49-29American Cancer Society Dietary GuidelinesEat more high-fiber foodsFive or more servings of fruits and vegetables dailyLimit consumption of processed and red meatsAdopt a physically active lifestyleAchieve and maintain a healthy weightLimit consumption of alcoholic beverages49-30Very Good!Apply Your KnowledgeMatch food group to appropriate color:VegetablesOilsMeat and beansGrainsFruitsMilk productsOrange Purple Blue Yellow Red Green ANSWER:49-31Assessing Nutritional LevelsAge Health statusHeight/weightBody frameBody circumference% of body fatNutrition and exercise patternsEnergy needsAlsoCultureBeliefsLifestyleEducation49-32Assessing Nutritional Levels (cont.)Measure fat as % of weightSkinfold test Measurement of the thickness of a fold of skin with a caliperTotal % of fatOptimal % differs between men and womenAging changes ratio – fat replaces muscle tissue49-33Modified DietsFactors affecting dietary needsPregnancyInjury DiseaseVegetarian dietAgingGenetic disordersSubstance abuse49-34Modified DietsModificationsRestriction of certain foodsEmphasis on particular foodsChange in daily caloric intakeChange in the amount of a specific nutrientChange in the texture of foodsAlteration in the number of daily mealsChange in variables such as bulk or spiciness49-35Specific Modified DietsFor treatment or prevention of certain conditionsModifications include changes inTexture Liquid or softHigh-fiberNutrient levelLow sodiumReduced calorieFrequency and timing Three smaller mealsTiming in relation to a procedureExclusions – for food intolerances49-36Specific Modified Diets (cont.)Supplements and parenteral nutritionOral – specially formulated to provide adequate nutrientsParenteral – given IV to bypass the digestive systemDrug therapyDrugsChange in food intakeChange in absorptionFoods Interfere with metabolism and action of a drug49-37Patients with Specific Nutritional NeedsFood allergiesWheat, milk, eggs, and chocolateEliminate from dietAnemiaIron supplementsDietary ironCancerIncrease caloric intakeAdequate protein intakeDiabetesFood exchange systemDiabetes food pyramidElderly Energy and metabolic requirements decreasePhysical difficultiesMedications Social factorsEconomic factors49-38Patients with Specific Nutritional Needs (cont.)Lactose sensitivityLactase not present to break down lactoseOverweightDietary modificationBehavior modificationMotivation and educationHeart disease Reduce cholesterolLose weight if neededReduce consumption of fatsHypertensionDecrease sodium/ increase potassium/ adequate calciumEliminate or reduce alcohol consumption49-39Patients with Specific Nutritional Needs (cont.)PregnantAdditional proteinCalciumIronFolic acidFiberLactating Additional calories and proteinFolic acid and calciumChildren 1st year Breast milk or commercial formulaCow’s milk inadequateNutritional needs change Growth spurtsMaturationIncreasing activityHunger regulates intake49-40Apply Your KnowledgeWhat factors does the physician consider when assessing a patient’s nutritional status?ANSWER: The physician considers a patient’s age, health status, height and weight, body frame and circumference, percent of body fat, eating and exercise patterns, and energy needs. Culture, beliefs, lifestyle, and educational level should also be considered during the assessment.49-41Apply Your Knowledge2. Matching___ Eliminate foods from diet A. Change in texture ___ Food exchange system B. Children___ Decreased metabolism C. Food allergies___ Hunger drives eating D. Parenteral nutrition___ Modification to a soft diet E. Diabetes___ Reduced sodium diet F. Elderly___ Bypasses GI tract G. Drug therapy___ May alter food intake and absorption H. Change in nutrient levelANSWER:HGFEDCBAYippee! 2 for 2!49-42Eating DisordersExtremely harmful eating behaviorAnorexia nervosaSelf-starvationTreatmentRestore normal nutritionPsychotherapy Education of nutrition conceptsChronic condition – can be fatal49-43Eating Disorders (cont.)Bulimia Binge and purge by vomiting, diuretics, laxativesUsually easier to treat than anorexiaTreatmentMedication PsychotherapyGoalsEstablish a healthy weightEstablish good eating patternsResolve psychosocial triggers49-44Eating Disorders (cont.)Getting help – be alert to patient report ofSkipping at least two meals per dayUncontrolled eating of large amounts of food Using laxatives or other purges to control weightAvoiding social situations that interfere with diet or exerciseFeeling disgust, depression, and guilt after bingeFeeling that food controls life49-45Apply Your KnowledgeA young female patient arrives at the clinic showing a 15 pound weight loss in the last two months. Her weight is 10 pounds under the average weight for her height. She states she “feels great.” What should you do?ANSWER: Document the weight loss and report it to the physician. She may be suffering from anorexia nervosa or bulimia, two types of eating disorders that require medical care and psychotherapy.Right!49-46Patient EducationReinforce nutrition instructionsTeach patientRole nutrition plays in preventing illnessesHow to be wise consumers by reading food package labelsFactors Patient likes and dislikesPatient age and family circumstancesDiseases and disordersPatient’s psychological condition49-47Patient Education (cont.)GuidelinesTeach patient as an individualTeach a small amount at a timeKeep explanations at patient’s level of understandingReinforce good eating behaviorLet patient be an active learnerProvide a written diet planSuggest support groups49-48Patient Education (cont.)Cultural considerationsInfluenceFood purchases Like and dislikesMeal timing and frequencyAttitude toward supplementsSnacking Adjust diet and recipes accordingly 49-49Apply Your KnowledgeWhat do you need to consider when teaching patients about nutrition?ANSWER: You need to consider patient likes and dislikes, age and family circumstances, diseases and disorders, and the patient’s psychological condition. In addition, you need to incorporate cultural considerations into nutritional education.Excellent!49-50In Summary49.1 The body uses food for three major purposes: to provide energy; to build, repair, and maintain body tissues; and to regulate body processes.49.2 Calories provide energy for the body. Calories are measured in the foods we eat. We can also estimate the amount of calories used by the body during activity. 49.3 The body needs a variety of nutrients for energy, growth, repair, and basic processes. There are several food components that provide nutrients. These are proteins, carbohydrates, fiber, lipids, vitamins, minerals, and water.49-51In Summary (cont.)49.4 Dietary guidelines suggest the types and quantities of food that people should eat each day. They may also contain recommendations about which types of foods to limit and which types of foods to increase.49.5 The Food Guide Pyramid provides recommendations for eating a variety of nutrients and maintaining physical activity. Following the Food Guide Pyramid recommendations promotes a well-balanced diet and healthy lifestyle.49.6 Calipers are used to perform a skinfold test that determines the percentage of body fat.49-52In Summary (cont.)49.7 Dietary modifications may be used alone or in combination with other therapies to prevent or treat illness.49.8 Patients with allergies, anemia, cancer, diabetes, advancing age, heart disease, hypertension, lactose sensitivity, and obesity need special diets. In addition, pediatric, pregnant, lactating, and debilitated patients, as well as those undergoing drug therapy, need modifications to their diet. 49-53In Summary (cont.)49.9 You should now the signs and symptoms of eating disorders in order to evaluate for these disorders during the patient interview. Some of the more common signs and symptoms for each include:anorexia nervosa – unexplained weight loss, self-starvation, and fear of weight gainbulimia – eating large quantities of food in a short period of time, going to the bathroom immediately after eating, and using laxatives to excessbinge eating – not followed by purging and weight gain49-54In Summary (cont.)49.10 You may play a major role in educating patients about special diets and in helping them to implement dietary changes as instructed by physicians and dietitians. Knowledge of basic nutritional principles and current nutritional findings will help you perform these tasks with confidence and competence.49.11 Documenting nutritional education is part of preventative health care practice and is required to help ensure payment by managed care and other health insurance companies.49-55End of Chapter 49He that eats till he is sick must fast till he is well.  ~English Proverb