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Chapter 7 Nutrition
Chapter 7NutritionSarah Loch RN MSNFall 2015
NutritionThe science of food as it relates to optimal health and performance
Nutrition in the health historyFrom the history and physical examination, assess the patients nutritional status, including the following:Recent growth, weight loss, or weight gain Chronic illnesses affecting nutritional status or intake Medication and supplement use Nutrition screen Assessment of nutrient intake Clinical signs or symptoms of nutrient or energy deficiency Laboratory values
Nutrition assessmentObtain the following anthropometric measurements and compare them to standardized tables:Standing height Weight Calculate body mass index Waist circumference Calculate waist-hip ratio Triceps skinfold (TSF) thickness and midupper arm circumference (MAMC) measurements; calculate midarm muscle circumference/midarm muscle area (MAMA)
Review: macronutrientsCarbohydrate, protein, and fat are referred to as macronutrients because they are required in large amounts.These three macronutrients provide the calories needed to produce energy in the human body.Carbohydrate, a nutrient found mostly in plants and in milk, is considered the bodys main source of energy.About 365 g is stored as glycogen in the liver and muscle tissues, which provides energy for only about 13 hours of moderate activity.
Review: CHOIf more carbohydrates are eaten than are needed for energy, the excess is stored in fatty tissues throughout the body.It is recommended that carbohydrate content of the diet be at least 50% of total calories, with no less than 100 g being consumed per day.
Review: CHOCarbohydrates also serve major functions in vital organs:LiverSparing the use of protein for energy and participating in specific detoxifying metabolic pathwaysHeartAs glycogen stored in cardiac muscleCentral nervous systemAs the only energy source to the brain
Review: ProteinsProtein, present in all animal and plant products, is essential to life.It is a part of more than half the organic matter in the body.Twenty different amino acids combine in different ways to form proteins.Nine amino acids are considered essential because they cannot be manufactured by the body and are essential for normal growth and development.
Review: ProteinsThe major functions of protein include the following:Building and maintaining tissuesRegulating internal water and acid-base balancesActing as a precursor for enzymes, antibodies, and several hormonesIf more protein is eaten than is needed for these major functions, the surplus either is used to supply energy or is stored as body fat if total calorie intake is in excess of needs.
Review: ProteinsIt is recommended that protein content of the diet be 14% to 20% of total calories, or a daily minimum of: 13 g in infants 25 g in children 45 g in adults
FatsFat, which is present in fatty fish, animal, and some plant products (particularly the seeds of plants), is necessary as the main source of: Linolenic acid (omega-7 fatty acid) -Linolenic acid (omega-3 fatty acid)Fatty acids are essential for normal growth and development.
FatOther major functions of fat include the following:Synthesis and regulation of certain hormonesMaintenance of tissue structureNerve impulse transmissionMemory storageEnergy metabolismIf more fat is eaten than is needed for these functions, the extra is stored in fatty tissues in the body.
FatSome fatty tissues, especially those under the skin and around the abdominal organs, serve additional purposes: As a reserve store of fuel to be used when calorie intake does not meet needsSupport and protect organs from injuryPrevent undue loss of heat from the body surfaceIt is recommended that fat content of the diet be 25% to 35% of total calories, or at least 20 to 35 g/day.
MicronutrientsSubstances that are required and stored in very small quantities by the bodyVitaminsMinerals (elements)ElectrolytesNot used as a source of energy but are essential for: Growth Development Hundreds of metabolic processes that occur daily
MicronutrientsVitamins and minerals must be taken in either through food or by supplement.Micronutrients cannot be metabolized by the body, except:Vitamin K and biotin (produced by certain intestinal microorganisms)Vitamin D (synthesized from cholesterol)Niacin (synthesized from tryptophan)
WaterMost vital nutrient; adult body is 55% to 65% water.An individual can exist without food for several weeks, but without water, an individual would last only a few days.Major functions:Provide turgor to body tissuesAlter configuration of substances for metabolic processesTransport body nutrients and wastesMaintain stable body temperature
WaterThere is a continual loss of water from the body by the:Kidneys as urine Lungs as water vapor in expired air Skin as perspirationApproximately 2 to 2 L of water are lost daily, which are replaced by: Fluids taken inWater contained in solid foods eaten Water produced in the body as a result of oxidative processes
Ways to measureProcedures for accurately measuring:HeightWeightTriceps skinfoldTable of norms for relevant age and gender groupsThese measurements are useful in assessing patients nutritional status and risk for disease.
Ways to measureBody mass index (BMI)Formula used to assess nutritional status and total body fatWaist circumferenceLarge waist circumference often associated with increased risk for type 2 diabetes, dyslipidemia, hypertension, and cardiovascular diseaseMonitoring over time may aid in predicting disease risk for cardiovascular and obesity-related diseases
Ways to measureWaist-to-hip circumference ratioNot as helpful as the body mass index in assessing total body fatAn excess proportion of trunk and abdominal fat (e.g., apple-shaped body) has a higher risk association with diabetes mellitus, dyslipidemia, metabolic syndrome, stroke, and ischemic heart disease than does a larger proportion of gluteal fat (e.g., pear-shaped body).
Measurement of waist circumference (A) and hip circumference (B)
to calculate the waist-to-hip circumference ratio: waist circumference (cm)/hip circumference (cm) = waist-to-hip ratio.
Assessing diet adequacyThe history of an individuals food intake allows estimation of the adequacy of the diet.24-hour recall dietMost simple method for food intake historyFood diaryMost accurate and time-consuming method
Measures of diet adequacyComputerized nutrient analysis programs offer quickest and most efficient method of analyzing nutrient intake.Quickest method of estimating adequacy is simply comparing individual intake with recommended servings and portions listed in the MyPyramid food guide.
Measures of Nutrient Analysis MyPyramid food guideIndicates number of servings from each food groupFood-based guidance to help implement recommendations for the 2010 Dietary Guidelines for AmericansFocus on nutrient dense food. Balancing caloriesAvoid oversize portionsHalf of the plate fruits and veggiesWater instead of sugary drinks
Measures of Nutrient Analysis Vegetarian dietsCan meet all the recommendations for nutrientsKey is variety, as well as amounts to meet calorie needsFive nutrients may be deficient: protein, calcium, iron, vitamin B12, and vitamin DEthnic food guide pyramidsFood guide pyramids for ethnic populations are available (e.g., Mediterranean, Indian, Mexican, and Asian)
Special ProceduresTriceps skinfold thicknessApproximately 50% of the body fat is present in the subcutaneous tissue layersCorrelation exists between the triceps skinfold thickness and the bodys fat content
Other Special proceduresMidupper arm circumference (MAMC)Estimate of muscle mass and available fat and protein stores Midarm muscle circumference/midarm muscle area (MAMA)Sensitive index of body protein reserves
LabsHemoglobin (g/100 mL)Hematocrit (%)Serum albumin (g/100 mL)Serum cholesterol (CHOL) (mg/100 mL)Serum triglycerides (TRI) (mg/100 mL)
LabsHigh-density lipoproteins (HDL) (mg/100 mL)Low-density lipoproteins (LDL) (mg/100 mL)Serum glucose (mg/100 mL)Hemoglobin A1c (%)Serum folate (ng/mL)