Nutritional Assessment Part 1 PDF

Nutritional Assessment Part 1 NUTR 344 – WINTER 2023 Lecture content Nutritional assessment vs. screening Components of nutritional assessment ◦ Anthropometry + body composition ◦ Biochemical ◦ Clinical ◦ Dietary ◦ Environmental ◦ Functionnal Required readings Nelms textbook, Chapter 3 and re...

Nutritional Assessment Part 1 NUTR 344 – WINTER 2023 Lecture content Nutritional assessment vs. screening Components of nutritional assessment ◦ Anthropometry + body composition ◦ Biochemical ◦ Clinical ◦ Dietary ◦ Environmental ◦ Functionnal Required readings Nelms textbook, Chapter 3 and related Appendices D-G. Additional reference for consultation: Gibson, R.S. Principles of Nutritional Assessment, 2nd edition, Oxford University Press, 2005. Useful definitions Nutritional status: the condition of the body’s nutrient stores as a result of the intake, absorption, and metabolism of energy and nutrients, and the influence of physiological needs and disease-related factors. Nutritional risk : risk of having nutrition-related health problems (could be dietary and pathology-related) Nutritional screening vs. assessment Screening: process of identifying characteristics known to be associated with nutritional problems ◦ Purpose is to quickly identify individuals with nutritional risks ◦ Should be easy to use, cost effective, valid, reliable, sensitive Assessment: a systematic method for obtaining, verifying, and interpreting data needed to determine nutritional status, nutrition-related problems, their causes, and their significance ◦ Most often performed by dietitian ◦ Includes medical and dietary history, physical examination, anthropometric measurements and analysis of biochemical and functional status. Subjective and objective data. Nutritional screening “Process of identifying patients, clients or groups who may have a nutrition diagnosis and benefit from nutrition assessment and intervention by a registered dietitian.” Academy of Nutrition and Dietetics (AND) Nutritional Screening - Components Weight loss (involuntary) Dietary Intake     Appetite Dietary restrictions Intolerances Route of feeding (oral, enteral, TPN) Pre-existing conditions causing nutrient loss  Malabsorption, diarrhea Conditions that increase nutrient requirements  Inflammation, fever, burns, sepsis, injury Nutritional assessment: Goals To identify patients needing nutritional support To use as a baseline for monitoring and evaluating the response to our nutritional intervention plan  For:  Disease prevention and management  Identify specific deficiencies and/or  Overall malnutrition Why do we assess? Malnutrition is associated with increased: ◦ Morbidity (above and beyond the disease state) ◦ Mortality ◦ Hospital length of stay ◦ Use of health care services and costs Malnutrition affects more than 50% of hospitalized patients How do we assess? ◦Anthropometry + body composition ◦Biochemical ◦Clinical ◦Dietary ◦Environmental ◦Functionnal Evaluation/Interpretation of assessment Anthropometric Data o Established criteria (BMI) o NHANES I and II reference tables o Nutrition Canada reference tables: <5th and >95th percentile suggest nutritional risk See Nelms, Appendix D Biochemical data o Cut-off values, normal lab values (differ by institution) Evaluation/Interpretation of assessment Clinical Data  Physical signs and changes (i.e. presence or absence of edema) Dietary Data  DRIs - harmonization of U.S. and Canada  Canada: Canadian Food Guide on Healthy Eating  new in 2019 vs. previous  U.S.: USDA food pyramid  new Dietary Guidelines 2020-2025 Functional Data  Cut-offs from cohort studies Subjective vs. objective data Development of a nutritional deficiency Stage Depletion stage Method used 1 Dietary inadequacy Dietary 2 ↓ ssue reserve Biochemical 3 ↓ bodily fluid level Biochemical 4 ↓ func on or ssue Biochemical/anthropo 5 ↓enzyme ac vity Biochemical 6 Functional change Behavioral/physiological 7 Clinical symptoms Clinical 8 Anatomical signs Clinical Anthropometry and body composition Anthropometry = body size, weight and proportions Allow to assess body size and composition using: height, weight, circumferences, skinfolds, ratios Used to estimate nutritional status and evaluate intervention Measurements to be done in triplicates NOT to identify specific nutrient deficiencies Body Composition = body compartments (could be 2 – fat and fat-free mass – or more) Nelms, Chapter 3, section 3.6 Body Composition % of weight 100 Fat 160 000 kcal 75 65 Skinfold thickness Waist circumference Skeleton; Skin Extracellular water Fat-free mass 40 Plasma proteins Viscera Skeletal muscle 26 000 kcal Albumin, TTR, RBP Delayed hypersensitivity Arm muscle circumference (MAMC) Creatinine Height Index (CHI) Body Composition % of weight 100 Fat 160 000 kcal 75 65 Skeleton; Skin 4.5 kg Extracellular water Fat-free mass 40 Plasma proteins Viscera Skeletal muscle 26 000 kcal 0.3 kg 1.5 kg 6.0 kg Total protein (70-kg man) 12 kg Height Standing: using a stadiometer, (barefoot, heels and shoulders touching the wall, Frankfurt plane) Knee Height: If unable to stand (equations by age, sex and ethnicity p.52, in Nelms) Arm span  If unable to stand straight  not for Asians, African Americans, spinal deformities   not recommended Knee height calipers See Nelms, p.52 for equations Frame Size: useful to interpret percentiles of muscle area Wrist circumference ratio = height (cm) / wrist circumference (cm) Frame size Men Women Small >10.4 >11.0 Medium 9.6-10.4 10.1-11.0 Large <9.6 <10.1 Elbow breadth: see Appendix D1 p. A-64 Body weight Sum of all components at each level of body composition - measure of body stores Using standing, chair, or bed scales Wearing minimal clothing, no shoes Timing and hydration changes No single measure of weight accounts for body composition Consideration for amputations Amputation adjustments 7% 2.3% Example: current weight 70 kg with arm amputation 6.5% 0.8% 18.6% 7.1% Estimated body weight: 70 kg/ (100%-6.5%) = 74.9 kg Weight assessment: BMI Body Mass Index = weight (kg) / height2 (m2) For Males and Non-Pregnant Female Adults <65 years old BMI Interpretation <18.5 Underweight 18.5-24.9 Healthy 25-29.9 Overweight 30-34.9 Obesity - Grade I 35-39.9 Obesity - Grade II >40 Extreme Obesity - Grade III Weight assessment: BMI For Males and Female Adults 65 years and older BMI Interpretation <24.0 May be associated with health problems in some older adults 24.0-29.0 Healthy weight for most older adults >29.0 May be associated with health problems in some older adults BMI limitations Does not measure body composition Varies in relation to age, sex, ethnicity Limited applicability in athletes Must be accompanied by other measures, i.e. waist circumference  Better than weight or height alone and the only validated method for estimating healthy body weight To calculate healthy body weight Aim for normal BMI range 18.5-25 kg/m2 ◦ More towards higher range if the person is overweight/obese ◦ More towards lower range if the person in underweight Example: current height: 1.70 m, weight: 105 kg, BMI= 36.3 kg/m2 Healthy or reasonable weight: 25 x 1.702 = 72 kg Weight assessment: % usual body weight (UBW) % UBW = (current weight / usual BW) x 100 % UBW in adult men and non-pregnant women % UBW Interpretation 85-95 May indicate MILD malnutrition 75-84 May indicate MODERATE malnutrition <74 May indicate SEVERE malnutrition Weight assessment: % weight change Clinically relevant  predicts nutritional risk and health complications % change = (UBW – current weight)/ UBW x 100 % Weight change in adult males and non-pregnant females Time interval Significant loss (%) Severe loss (%) 1 week 1-2 >2 1 month 5 >5 3 months 7.5 >7.5 6 months 10 >10 unlimited 10-20 >20 Significance of involuntary weight loss Involuntary weight loss means loss of fat and fat-free mass Weight loss can predict: Mortality Surgical outcomes / post-operative complications Frailty Malnutrition Risk of functional impairment Body circumferences and areas To assess some skeletal muscle and body fat stores = body composition Mid-upper arm circumference (MAC) Mid-upper arm muscle circumference (MAMC) Mid-upper arm muscle area (MAMA) Corrected MAMA (cMAMA) Mid-upper arm fat area (MAFA) Waist circumference Skinfold thickness Indicative of subcutaneous adipose tissue Assumes that each site is representative of total body stores Should ideally use multiple sites: 1. Biceps 2. Triceps - most commonly used but not fully representative 3. Subscapular 4. Suprailiac Evaluation: reference tables for TSF and subscapular Skinfold calipers Mid-arm site: triceps skinfold and mid-arm circumference and area Body circumferences and areas Mid-upper arm circumference (MAC)  Reflects muscle, bone, subcutaneous fat  Not sensitive to changes in muscle Mid-upper arm muscle circumference (MAMC) ◦ Must measure MAC and TSF: MAMC = MAC (mm) - (π x TSF) ◦ Corrects for subcutaneous fat ◦ Insensitive to small changes in muscle Body circumferences and areas Mid-upper arm muscle area (MAMA)  More sensitive to changes in muscle than MAMC  More adequately reflects total body muscle mass, but insensitive to small changes in muscle  Less valid in elderly or obese than younger, healthier weight  MAMA = MAMC2 / 4π (includes bone) Corrected mid-upper arm muscle area (cMAMA)  Reflects only muscle without the bone  cMAMA = MAMA - 10 for men or - 6.5 for women Body circumferences and areas Mid-upper arm fat area (MAFA)  Reflects sub-cutaneaous adipose tissue stores  Better indicator of total body fat than a single skinfold measurement  MAFA = [TSF x MAC/ 2] - [π(TSF)2 / 4] Body circumferences and areas Reference data: percentiles from NHANES I and II (Nelms, Appendix D1) Percentile rank MAMA MAFA <5 Muscle deficit Fat deficit 5.1 - 15 15.1 - 85 Below average Average Below average Average > 85 Above-average muscle Excess fat Body circumferences and areas Waist circumference  Reflective of abdominal subcutaneous and visceral fat stores, Measure circumference at level of iliac crest/navel >102 cm in men; >88 cm in women = abdominal obesity  Indicates increased risk for CVD and type 2 diabetes independently of BMI  High BMI Low WC - Low risk  High BMI High WC - High risk Waist : Hip ratio  Estimates distribution of abdominal adipose and muscle tissue  >1.0 for males; >0.8 for females Waist circumference Body composition: other techniques Bioelectrical impedance (BIA) Dual energy X-ray absorptiometry (DXA) Air displacement plethysmography (BOD POD) Hydrodensitometry (under water weighing) Used to be the gold-standard Magnetic resonance imaging (MRI) Is the current gold-standard Bioelectrical impedance (BIA) Measures impedance to a low-frequency electrical current (mainly from fat) Estimates fat mass, fat-free mass, total body water Rapid, safe, non-invasive Different instruments, $ to $$ Limitations: ◦ Influenced by hydration status ◦ Less precise in atypical bodies ◦ Reference data is limited BIA instruments Dual energy X-ray Absorptiometry (DXA) Imaging technique, based on attenuation of radiation from different tissue densities ◦ Measures bone, soft lean and fat tissues, whole-body and segments ◦ Sufficient precision to assess short (≊8-12 weeks) and longer-term changes ◦ May estimate visceral fat Recognized as a gold-standard for bone density, reference method for body comp Limitations: ◦ Expensive $$$ but increasingly accessible in research settings ◦ Minimal exposure to radiation ◦ Assumes normal hydration status DXA scanner Air displacement (BOD POD) Total body volume measured by air displacement in a chamber Comparable to hydrostatic weighing: ◦ Based on fat and lean tissue density Limitations: ◦ Access to instruments, $$$ ◦ Residual lung volume must be measured Mini-Application #1 Mr. G. is a 45-year old male who presents with the following data: ◦ ◦ ◦ ◦ change = severe weight Height: 5’10” Current weight: 77 kg Usual weight: 84 kg (2 months ago) 8% loss TSF: 25th percentile low, but normal range doesn’t tell me much bc don’t have prior measure, can use this muscle MAMC: 50th percentile Complains of +++ diarrhea Do you want to see this patient or not? Why? Yes What other information would you want to obtain to make your assessment? Ask if weight loss voluntary