Nutritional Status Assessment

Session Information

• Session name: Assessment of nutritional status
• Session length: 120 minutes
• Session format: Class session

Learning Objectives

• Define nutritional assessment.
• Understand methods for assessing nutritional status.
• Understand basic anthropometric techniques, applications, and reference standards.
• Determine ecological factors of malnutrition and plan for control and prevention.

Definition of Nutritional Assessment

• Nutritional assessment is a dynamic process that evaluates the nutritional status of individuals, groups, or communities.
• It identifies major malnutrition problems and facilitates planning for prevention and control.
• It involves interpreting anthropometric, biochemical, clinical, and dietary data to determine nourishment levels.
• Nutritional assessment can be done using ABCD methods.

Purpose of Nutritional Assessment

• To identify individuals or populations at risk of malnutrition.
• To pinpoint individuals or populations that are already malnourished.
• To develop healthcare programs tailored to the community's needs as defined by the assessment.
• To measure the effectiveness of nutritional programs and interventions.

Methods of Nutritional Assessment

• Direct assessment (individual or group level) involves ABCD: Anthropometric, Biochemical, Clinical, and Dietary measurements.
• Indirect assessment (national level) involves:
  • Vital statistics (morbidity and mortality rates)
  • Assessment of ecological factors (national food consumption and food balance sheets)
  • Economic factors (per capita income, population density, and social habits).

Direct Methods of Nutritional Assessment (ABCD)

• 1.1 Anthropometric Measurement
• 1.2 Biochemical Assessment
• 1.3 Clinical Assessment
• 1.4 Dietary Assessment

Anthropometric Measurements

• Anthropometry measures body height, weight, and proportions.
• It includes measuring a person's physical parameters and compares them against a standard.
• Crucial component of clinical examinations, especially for infants, children, and pregnant women.
• It evaluates both under- and over-nutrition.
• Measured values reflect current nutritional status and not distinguish between acute and chronic changes.

Anthropometry in Adults

• Includes:
  • Body Mass Index (BMI) (weight and height)
  • Waist Circumference (WC)
  • Percentage of fat
  • Waist Hip Ratio (WHR)
  • Mid Upper Arm Circumference (MAC)
  • Triceps Skin Fold Thickness (TSF)
• These measurements are compared to a reference standard to assess weight status and disease risk.

Body Mass Index (BMI)

• BMI is an index of weight-for-height used as an international standard to assess body size in adults.
• It's the individual's weight in kilograms divided by the square of their height in meters (kg/m²).
• BMI is the measurement most applicable method for physicians.
• The BMI ratio (Kg/m²) estimates body mass status relative to height.

International WHO Classification of Adult Overweight & Obesity by BMI

• Underweight: BMI <18.50
• Normal weight: BMI 18.50-24.99
• Overweight (Pre-obese): BMI 25.00-29.99
• Obese:
  • Class I: BMI 30.00-34.99
  • Class II: BMI 35.00-39.99
  • Class III: BMI ≥40.00

Waist Circumference (WC)

• Waist circumference is the simplest way to measure "abdominal obesity."
• WHO measurement guidelines: at the midpoint between the lower margin of the last palpable rib and the top of the iliac crest.
• Waist circumference is measured at the level of the umbilicus to the nearest 0.5 cm.
• Subjects should stand erect with relaxed abdominal muscles, arms at the side, and feet together.
• Measurement should be taken at the end of a normal expiration.
• Waist measurement can assess obesity and the risk for NCDs, especially type 2 diabetes and CVDs.
  • WC >102 cm in males
  • WC >88 cm in females

Hip Circumference

• WHO measurement guidelines: Measure around the widest portion of the buttocks to the nearest 0.5 cm, with the tape parallel to the floor.
• Subject must stand, and the measurer should squat beside him.
• The measurements should be taken with a flexible, non-stretchable tape in close contact with the skin, without indenting the soft tissue.

Waist/Hip Ratio (WHR)

• WHR predicts mortality in older people better than waist circumference or BMI.
• WHR indicates the distribution pattern of subcutaneous adipose tissue.
• Fat distribution is an important indicator of CHDs.
• More abdominal fat increases the risk of CHD.
• WHR calculates by measuring the waist and hip, then dividing the waist measurement by the hip measurement.
• Men generally have higher WHRs than women.

WHR Values & Associated Health Risks

• Men:
  • Low risk: 0.95 or lower
  • Moderate risk: 0.96-1.0
  • High risk: >1.0
• Women:
  • Low risk: 0.80 or lower
  • Moderate risk: 0.81-0.85
  • High risk: >0.85
• WHR is not valid for children, people under five feet tall, and those with a BMI of 35 or higher.
• Android (Apple-shaped): More common in males, WHR usually >0.9, is associated with increased risk of CHD and type II DM.
• Gynecoid (Pear-shaped): More common in females, WHR usually <0.8, is associated with gynecological and obstetric complications.
• High-risk WHR (>0.80 for women, >0.95 for men) indicates central (upper body) obesity and increases the risk for diabetes and CVS disorders.

Measures of Body Composition

• Measures of body composition provide a more comprehensive picture of body composition & changes.
• These include:
  • Measurements of skin-folds
  • Mid-arm circumference
  • Mid-arm muscle circumference

Mid-Arm Circumference (MAC)

• Measured to assess nutritional status.

Skin-Fold Measurement

• Technique uses callipers measure the thickness of a "pinch" of skin and fat.
• Applied at specific body areas, such as triceps, chest, abdomen, suprailiac, and thigh.

Anthropometry for Children

• Accurate measurement of height and weight is essential for evaluating the physical growth of the child.
• Data used for growth monitoring plotted on a growth chart to calculate growth velocity, which can then be compared to international standards.
• Children of same age do not develop at the same rate, however there is a normal rate range.
• Monitoring growth is a basic screening tool for early detection of deviations from good health.

Growth Charts

• Growth charts graphically display a child's physical growth and development.
• Used in growth monitoring.
• They are graphs that record a child's growth progress, using anthropometric measurements over time to develop a growth curve.
• Growth charts routinely used in health centers plot weight against age.
• The direction of the growth curve is more important that the curve position.
• Note considerations for premature infants to avoid over-diagnosing growth failure. Subtract weeks of prematurity from postnatal age when plotting.
• Vertical axis is the weight axis (kilograms).
• Horizontal axis is the age axis.

Interpreting Growth Curves

• Growth chart display curves at the 5th, 50th, and 95th percentiles.
• Growth charts show curves for weight by age, with values at +2 and -2 standard deviations (SD) based on WHO reference values.
• Normal/acceptable growth occurs when the child's weight curve lies parallel between the 5th and 95th percentiles in the growth chart
• The curves should not be less than 5% and not more than 95%
• Over Weight : 85% - 95%.
• Failure to thrive / Under nutrition is below / less than 5%.
• Obese / Over nutrition is more than 95%.
• A normal growth curve, indicates a healthy child, is parallel to the printed curves on the chart.
• Note considerations on premature infants who may be over-diagnosed due to growth failure.
• Horizontal growth curve (static) indicates the child is not growing; the child’s medical history should be taken to establish cause of growth failure.
• Downward growth curve, indicates a dangerous situation, means that the child is losing weight.

Body Mass Index for Children and Teens

• Overweight for children and teens is defined using CDC growth charts. These provide body mass index-for-age percentiles for boys and girls aged 2-20 years.
• Interpretation of BMI uses age- and sex-specific percentiles.
• Body fat changes with age, and it also differs between girls and boys.
• BMI levels determined by weight and height, alongside the child’s age and sex.
• BMI is age- and sex-specific and referred to as BMI for-age.
• Percentile ranking is also determined (BMI percentile).
• Determined by BMI. Underweight is given if a child falls into the percentile of healthy weight, overweight, or obese.

Body Mass Index Table for Children and Teens

• Less than 5th percentile: Underweight
• 5th percentile to less than 85th percentile: Normal weight
• 85th percentile to less than 95th percentile: Overweight
• 95th percentile or greater: Obese

Advantages of Anthropometric Measurements

• Objective with high specificity and sensitivity.
• Measures several variables of nutritional significance (Ht, Wt, MAC, HC, skin fold thickness, waist & hip ratio & BMI).
• Readings are numerical& gradable on standard growth charts.
• They are reproducible.
• Non-expensive & need minimal training

Limitations of Anthropometric Measurements

• Inter-observer errors in measurement.
• Limited nutritional diagnosis.
• Problems with reference standards, such as local versus international standards.
• Subjective statistical cut-off levels for what is considered as abnormal values.

Biochemical and Biophysical Assessments

• Laboratory Assessments are important indicators of nutritional status.
• Hemoglobin estimation is the test and index for state of nutrition.
• Protein & trace nutritional element investigations
• Urine examination tests for albumin, sugar and blood.
• Stool examination for the presence of intestinal parasites.
• Specific lab tests offer Measurement of individual nutrient in body fluids.
• Detection of abnormal amount of metabolites in the urine.
• Analysis of hair, nails & skin for micro-nutrients.
• Biophysical (Radiological) Assessment like X-rays diagnose rickets.

Clinical Assessment

• Clinical methods of assessing nutritional status should involve:
  • Obtaining nutritional history.
  • Asking patients about symptoms suggestive of nutrient deficiency.
  • Checking for deficiency signs and organs of the body.
  • Detecting signs via general clinical examination.

Advantages of Clinical Assessment

• Fast and Easy to perform.
• Inexpensive.
• Non-invasive.

Limitations of Clinical Assessment

• Does not detect early cases.

Clinical Signs of Nutritional Deficiency

• Includes hair signs, mouth signs, skin signs, nail signs, thyroid gland signs, joins & bone signs, & eye signs.
• Hair Signs: Spare and thin hair (Protein, zinc, biotin deficiency), Easy to pull out (Protein deficiency), Coiled hair (Vit C & Vit A deficiency)
• Mouth Signs: Glossitis (riboflavin, niacin, folic acid, B12), Bleeding & spongy gums (Vit. C,A, K, folic acid & niacin), Angular stomatitis, cheilosis & fissured tongue (B 2,6,& niacin), leukoplakia (Vit.A, B12, B-complex, folic acid & niacin), Sore mouth & tongue (Vit B12,6,c, niacin, folic acid & iron)
• Skin Signs: Pallor (Folic acid, iron, B12), Follicular hyperkeratosis (Vitamin B & Vitamin C), Flaking dermatitis (PEM, Vit B2, Vitamin A, Zinc & Niacin), Pigmentation, desquamation (Niacin & PEM), Bruising, purpura (Vit K,Vit C & folic acid)
• Nails signs: spooning (Iron deficiency) Transverse lines (Protein deficiency)
• Thyroid gland signs: Goiter in mountainous sea places.
• Joins & bone signs: Rickets is a vitamin D deficiency.
• Eye signs: Night blindness, exophthalmia signs mean Vitamin A deficiency, Photophobia-blurring with conjunctival inflammation signs Vit B2 & vit A deficiencies

Clinical Signs of Nutrient Deficiency

• Includes:
  • Pallor: on palms, conjunctiva, tongue
  • Gets tired easily; loss of appetite; shortness of breath
  • Pitot's spots on the eyes
  • Goitre
  • Pitting edema
  • Severe visible wasting
• Each may be a sign of a abnormality.

Dietary Assessment & Evaluation

• Nutritional intake of humans is assessed by four different methods:
  • a-24 Hour Recall.
  • b-Food Frequency Questionnaire.
  • c-Food dairy record technique.
  • d-Direct observation of food consumption.

24-Hour Recall Method

• Description: A trained interviewer asks subjects to recall all food & drink in the previous 24 hours.
• Advantages: Easy and quick, suitable for large surveys, can be administered by telephone.
• Disadvantages: memory dependent, a poor observation that accuratratly dose not represent usual intake, under- and overestimation of food intake.

Food Frequency Questionnaire

• Written survey of food consumption over a period of time, usually one year.
• A list of around 100 food items is given to the subject to indicate their intake frequency and quantity per day, week, and month.
• Advantages : Examines long-term food intake, doesn't interfere with food choices, loe-cost,.
• Disadvantages: The calculated nutrient intakes may not be depends on memory and accurate.

Food Dairy Record

• The individual writes a report about food consumed during a specified number of days (3-7), which provides information about food habits and amounts consumed, and frequency of intake of certain nutrients.
• Advantages: Process don't rely on memory and are useful for controlling intake because keeping records increase awareness of food choices.
• Disadvantages: time consuming , under reporting and Recording process itself influence food intake.

Direct Observation

• Observation of food meal before and after eating
• Advantage: Process don't rely on memory, doesn't interfere with food choices
• Disadvantages: Possible only in residential condition Requires observer's full time

Interpretation of Dietary Data

• Qualitative method: foods are classified into 5 groups (cereals, vegetables & fruits, milk & milk products, meat & fish & poultry & fat and oils), which determine numbers and compares to what is recommended
• Quantitative method: Amount of energy and specific nutrients in each food is calculated

Indirect Methods for Nutrition Assessment

• Includes indirect assessment at the (National level)
• 1.Vital statistics: Morbidities and Mortalities
• 2.Assessment of ecological factors
• 3. National Food Consumption & Food Balance Sheet

Vital Statistics

• Includes mortality rate: Malnourished children more prone to infections and death and Infant mortality/under five high rates.
• Morbidity rates: Malnutrition or related infections as diarrhea would be indirect indicator.

Assessment of Ecological Factors

• A- National Food Consumption
  • Total Food Consumption = (food produced locally + food imported) – (food exported + food used agriculture, industry or animal feed)
• Average Food Consumed Per Capita per day = Total Food Consumed/ Mid Year Population X 365

Food Balance Sheet

• It shows the average daily per capita intake from different food items in a year (meat, milk, fish).
• Foods are analyzed into their component nutrients and energy supply using a special food composition table.
• Illustrating the overall national food supply and the pattern of food consumption, but this Sheet of individuals/groups do not demonstrate the nutritional status.
• Characteristics of Egyptian diet:
  • Cereals form a good bulk of diet.
  • Energy intake exceeds energy requirements.
  • Animal food intake is low.
  • Protein is mainly from plant source.
  • Iron intake mainly obtaind from cereals.

Assessment of the Ecological Factors of Malnutrition

• Includes:
  • Cultural factors which influence national food habits, infants' feeding attitudes and traditions in food prep.
  • Socioeconomic Condition: family size, income, occupation, education, food storage, food prices and importation.
  • Leads to malnutrition.
  • Health and education.
  • Services and health facilities.

Factors Causing Malnutrition

• Agent: food shortage/maldistribution
• Host: age, sex, feeding habits, food fads, religious habits, alcohol intake, nutritional status, socioeconomic status.
• Environmental factors: geographical and social environment.

Prevention of Malnutrition

• A- At the Family level:
  • Nutrition education.
  • Breast feeding.
  • Stress the special needs for the vulnerable groups.
• B- At the Community level
  • Improve Socioeconomic development.
  • Improve Sanitary environment.
  • Prevention and Control of infectious diseases.
  • Food Supplementation and fortification.
• C- At the National level
  • Increase agricultural production.
  • Population control.
• D- At the International level
  • International agencies that can help developing countrioes.