Introduction - Nutrition Assessment July 2015

1

Introduction

to

Nutrition Assessment

A/Prof Rozanne Kruger - 2015151.232

Learning objectives

� To identify the need for nutritional

assessment

� To know the different methods / techniques

for assessing the nutritional status

� To identify uses / applications, strengths

and weaknesses of the main sources of

nutritional status information

Famous Quote

� “If we could give every individual the right

amount of nourishment and exercise, not too

little and not too much, we would have found

the safest way to health.”

� Hippocrates c. 460-377 B.C.

INTRODUCTION

The nutritional status of an individual is often

the result of many inter-related factors.

It is influenced by food intake, quantity &

quality, & physical health.

The spectrum of nutritional status spread from

obesity to severe malnutrition

Good nutrition

Well being

Society Individuals

Most NB

modifiable

lifestyle

determinant

“DIET” Poor nutrition

Disease

Adult death

Heart disease

Ht, Stroke

Diabetes

Cancer

“DIET”

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Nutritional Assessment

Evaluation of nutritional status

State of health resulting from the consumption, digestion, absorption,

transport and utilization of nutrients.

May be influenced by pathological factors.

Intake

Optimal Nutritional Status

Needs

To define the nutritional problem of

the targeted population, it is

necessary to measuremeasuremeasuremeasure its nutritional nutritional nutritional nutritional

status.status.status.status.

Practical use

Nutritional status assessmentsNutritional status assessmentsNutritional status assessmentsNutritional status assessments enable us to

determine whether the individual is well-

nourished or undernourished.

ASSESSMENT

of the nutritional situation in target population

ACTION

based on the analysis & available resources

Source: UNICEF, Triple-A Cycle

ANALYSIS

of the causes of the problem

NutritionNutritionNutritionNutrition impacts onimpacts onimpacts onimpacts on

→→→→ human growth & developmenthuman growth & developmenthuman growth & developmenthuman growth & development

..requires accurate assessment of ..requires accurate assessment of ..requires accurate assessment of ..requires accurate assessment of

A B C D (E)A B C D (E)A B C D (E)A B C D (E)

→→→→ standardized methodsstandardized methodsstandardized methodsstandardized methods

Two outcomes of NA

� The purpose of nutrition assessment is to collect and interpret relevant patient/client information to identify nutrition-related problems and their causes. � It is the first step in the Nutrition Care Process

� Used in nutrition monitoring and evaluation where similar or same data may be used to determine changes in client behavior or nutrition status and the efficacy of nutrition intervention

Levels of Nutritional AssessmentMinimal Minimal Minimal Minimal Screening MidMidMidMid----LevelLevelLevelLevelComprehensiveComprehensiveComprehensiveComprehensive

In-depth evaluation with multiple tools – any setting

Individual Clinical/

Community Setting

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Explore the importance of

Nutritional Assessment in...

� Public health� Nutritional monitoring & surveillance of populations for dietary adequacy or

risk

� Public policy decisions ~ e.g. food assistance programs� Fortification, safety & labeling,

� Development of public health recommendations for dietary intake

� Clinical or hospital settings � determination of dietary adequacy or risk for treatment / counseling

� Data can be used to characterize patient populations

� Community settings � Wellness/rehabilitation centers � Long-term care

� Research activities� Epidemiological studies on dietary intake and disease risk / group

comparisons e.g. intervention vs. control group or randomized control trials

Nutrition Assessment Involves

Critical Thinking

� Determine appropriate data to collect

� Select valid and reliable tools

� Distinguish relevant from irrelevant data

� Select appropriate norms and standards for

comparing the data

� Organize and categorize data in a meaningful

way that relates to nutrition problems

Progression of Nutritional Deficiencies

OptimalInadequate intake, impaired absorption or increased need

Marginal Depletion of tissue levels (at risk) and body stores (gradual)

Altered biologic, cellular and physiologic functions (subclinical)

Deficits Clinical or overt signs

Morbidity Mortality

Dietary

Anthro-pometric

Bioche-mical

Clinical &

Functional

Vital Stats

TOOLS

Stages in the Development

of a Nutrient Deficiency

Assessment Measurements

� Anthropometry� Measurements of changes in:

� physical dimensions (growth & development) and

� body composition

� Include height, weight, body mass index, growth chart percentile, growth rate, and rate of weight change.

� Biochemistry (biomarkers)� Measurements of nutrients and metabolites in body fluids and tissues� Reflects either nutrient intake or impact of nutrient intake.

Assessment Measurements (cont.)

� Clinical/Physical

� Ascertains clinical consequences of imbalances

nutrient intakes

� Subjective evaluation of overt signs and

symptoms of malnutrition

� Include oral health, general physical appearance, muscle and subcutaneous fat wasting

� Includes medical history.

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Assessment Measurements (cont.)

� Dietary

� Estimate food and / or nutrient intakes

� Measurements of food consumption (observed or

reported).

� Functional

� Measurements of physiologic performance and

activities.

Nutr Ass : A = Anthropometry

� Anthropos = human; metron = measure

� Purposes:� Evaluate progress in growth (women, children, adolescents)� The measured values reflects the current nutritional status

� don’t differentiate between acute & chronic changes.

� Detect malnutrition (over & under) (all ages)� Measure changes in body composition over time

� Compare measurements taken on an individual with:� population standards specific for gender & age (to reveal level) or � with previous measures (to reveal changes)

� Specific measures are used for specific situations:� Head circumference - brain growth� Abdominal girth measurement – abdominal fluid retention in liver disease or CVD risk

Variation in Anthropometry

Genetic

� Paternal and maternal genetic effects

� Effects linked to X or Y

chromosome

� Sex limited effect

� Pleiotropism

Non-genetic

� Nutritional status

� Disease state

� Nutrition X infection

� Age or maturity

� Psychological stress

� Measurement error

� Other environmental factors (e.g. altitude, pollution)

Nutr Ass : A = Anthropometry� Measures of growth and development

� Length (recumbent length / crown-heel), stature (or height), or knee height /armspan

� Weight – Hamwi (% IBW) / Devine equations

� Head circumference

� Chest circumference

� Elbow breadth (frame size)

� Analysis of measures (reference data)

� Infants & children - attained size vs. growth (growth charts), BMI standards (Cole)

� Adults – relative weight-for-height standards e.g. BMI

Nutr Ass : A = AnthropometryWeight Status as a Predictor of

Morbidity and Mortality

� In young to middle aged adults, morbidity/

mortality is highest in the highest quintile of

BMI

� In the elderly, morbidity/mortality is highest in

the lowest quintile of BMI

� In most populations, there is a J-shaped

relationship between mortality and BMI

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Body Mass Index and Mortality Risk

(Adapted from Bray GA. Gray DS, Obesity, part 1: Pathogenesis. West J Med 149:429, 1988; and Lew EA, Garfinkle L; Variations in mortality by weight among 750,000 men and women. J Clin Epidemiol 32:563, 1979.)

� Strong evidence from RCTs and epidemiological studies demonstrating relationship between BMI classification and risk for morbidity and mortality

� Analysis from 57 prospective studies shown that with every 5kg/m2 BMI increase above 22.5-25kg/m2 there is an 30% increase in overall mortality� DM, Renal, Hepatic D – 60-120% ↑ risk

� Vascular D – 40% ↑risk

� Respiratory D & all other D – 20% ↑risk

� Inverse association with BMI<22.5-25kg/m2 & overall mortality due to respiratory D & lung C

� Excess mortality at BMI>40kg/m2 ≡ smoking

Weight Status as a Predictor of

Morbidity and Mortality

Anthropometrics in Pediatrics

� Rate of length or height gain reflects long-term

nutritional adequacy

� Head circumference: used to evaluate growth in

children <3 years of age; usually detects non-

nutritional abnormalities

� A more sensitive measure of nutritional adequacy

than height, and reflects recent nutritional intake


� Measures of body fat and lean tissue

� Significant weight changes can reflect over/under nutrition with respect to energy & protein

� To estimate the degree to which fat stores or lean tissues are affected by nutrition

� Measures include:� Skinfolds

� Waist circumference

� Waist-to-hip ratio

� Hydrodensitometry

� Bioelectric impedance

� Arm circumferences

Nutr Ass : A = Anthropometry� Measures of body fat and lean tissue

� Skinfolds

� Triceps, biceps, subscapular (below shoulder blade), suprailiac (above hip bone), abdomen, upper thigh

� Good estimation of total body fat

� Fair assessment of the fat’s location


� Waist circumference predicts mortality better

than any other anthropometric measurement.

� It has been proposed that WC alone can be

used to assess obesityMALE FEMALE

LEVEL 1 > 94cm > 80cm

LEVEL 2 > 102cm > 88cm

� L 1 = maximum acceptable WC irrespective of adult age;

there should be no further weight gain.

� L 2 = obesity; requires weight management to reduce the

risk of type 2 diabetes & CVS complications.

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Higher health risk Lower health risk

Male (apple) Female (pear)


� Measures of body fat and lean tissue

� Waist circumference

� Smallest area below the ribcage and above the umbilicus

� Indicator of fat distribution; abdominal visceral obesity

� WHR

� Measure the waist (abdominal) circumference

and the hip (gluteal) circumference

Nutr Ass : A = Anthropometry� Measures of body fat and lean tissue

� Hydrodensitometry

� Weighed on land & submerged in water (body fat estimate)

� Bioelectric impedance

� Measure body fat using very-low-intensity electrical current

� Mid-Upper-Arm Circumference (MUAC)

� Correlated with total muscle mass - in combination with TSF can determine arm muscle area (lean body mass).

� A useful index of protein status.

� Mid-Upper-Arm Muscle Circumference (MAMC)

� MAMC corrects for the contribution of subcutaneous fat

MAMC=MUAC cm – (TSF mm X 0.314)


� Other measures of body composition

� Body density: under water weighing, BodPod

� Isotope dilution (total body water)

� DEXA - dual-energy x-ray absorptiometry; bone

mineral density and fat and boneless lean tissue

� Total body electrical conductivity

� Magnetic resonance imaging (MRI): size of skeleton

and internal organs; abdominal fat

ADVANTAGES OF ANTHROPOMETRY

� Objective with high specificity & sensitivity

� Measures many variables of nutritional significance

(Ht, Wt, MAC, HC, skin fold thickness, waist & hip

ratio & BMI).

� Readings are numerical & gradable on standard

growth charts

� Readings are reproducible.

� Non-expensive & need minimal training

LIMITATIONS OF

ANTHROPOMETRY

� Inter-observers errors in measurement

� Limited nutritional diagnosis

� Problems with reference standards, i.e. local versus international standards.

� Arbitrary statistical cut-off levels for what considered as abnormal values.

Nutr Ass : B = Biochemical

� Determine what happens to the body internally to:� detect sub clinical or marginal deficiencies

� enhance or support other nutritional data

� Typical tests include:� analysis of blood or urine for nutrients, enzymes and metabolites that reflects nutritional status

� other tests to help pinpoint disease-related problems with nutrition related implications e.g. organ function

� biopsy of tissues

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Nutr Ass : B = Biochemical

� Interpretation of biochemical data requires skill

� No single test can reveal nutrition status due to the various factors influencing the results

� Best approach to combine with other parameters / assessment data e.g.

vitamin/mineral analyses + diet histories + physical findings� Many nutrients interact

� Diseases influence biochemical measures

� Exceptionally useful in detecting subclinical malnutrition

Nutritional AssessmentBODY COMPARTMENTS

ADIPOSE TISSUE 25%

ASSESSED BY

Triceps Skinfold

Body Weight

SOMATIC PROTEINS 30%

Arm Muscle Circumference

Body Weight

Creatinine Height Index

VISCERAL PROTEINS 8% Serum Albumin, Transferrin

PLASMA PROTEIN 3%

EXTRACELLULAR 20%

Serum electrolyte levels

SKELETON 10% DEXA

Advantages of Biochemical Methods

It is useful in detecting early changes in body

metabolism & nutrition before the appearance of

overt clinical signs.

It is precise, accurate and reproducible.

Useful to validate data obtained from dietary

methods e.g. comparing salt intake with 24-hour

urinary excretion.

Limitations of Biochemical Method

Time consuming

Expensive

They cannot be applied on large scale

Needs trained personnel & facilities

Nutr Ass : C = Clinical

� Detect signs and symptoms of malnutrition –deficiency or toxicity

� Medical history: previous illness, duration

� Physical assessment: hair, skin, nails, eyes, mouth (gums,

teeth, tongue), glands, bones, muscle

� Physiological Tests: Immune competence, taste acuity, night blindness, muscle function, cognitive function

� Requires trained observer – inter observer variability

� Deficiency usually severe before clinically evident

� Symptoms may be caused by non-nutritional factors

� Symptoms may relate to several nutrients

Clinical signs of nutritional deficiency

HAIRProtein, zinc, biotin

deficiency

Sparse & thin

Protein deficiencyEasy to pull out

Vit C & Vit A

deficiency

Corkscrew

Coiled hair

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MOUTHRiboflavin, niacin, folic acid, B12 , pr.

Glossitis

Vit. C,A, K, folic acid & niacinBleeding & spongy gums

B 2,6,& niacinAngular stomatitis, cheilosis& fissured tongue

Vit.A,B12, B-complex, folic acid & niacin

leukoplakia

Vit B12,6,c, niacin ,folic acid & iron

Sore mouth & tongue


EYES

Vitamin A deficiencyNight blindness, exophthalmia

Vit B2 & vit A

deficiencies

Photophobia-blurring,

conjunctivalinflammation


NAILS

Iron deficiencySpooning

Protein deficiencyTransverse lines


SKIN

Folic acid, iron, B12Pallor

Vitamin B & Vitamin CFollicular hyperkeratosis

PEM, Vit B2, Vitamin A, Zinc & Niacin

Flaking dermatitis

Niacin & PEMPigmentation, desquamation

Vit K ,Vit C & folic acidBruising, purpura

CLINICAL ASSESSMENT

� ADVANTAGES

� Fast & Easy to perform

� Inexpensive

�Non-invasive

� LIMITATIONS

�Did not detect early cases

Why do we need to know what people eat?Why do we need to know what people eat?

� Link with health measures (eg. saturated fat intake and blood cholesterol)

� Population trends in food intake over time

� Evaluation of public health campaigns

� Evaluation of population risk

� Identifying at-risk populations

� Economic reasons

Nutr Ass : D = Dietary Assessment

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Methods of Obtaining Intake Data?Methods of Obtaining Intake Data?

� Retrospective

� Prospective

� Qualitative

� Quantitative


Measurement of Food Intake

� 24 hr recall

� Estimated food record

� Weighed food record

� Dietary history

� Food frequency questionnaire

� Apparent consumption


24 Hour Recall24 Hour Recall

� Subject recalls food intake past 24 hours

� Quantities estimated with household measures

� Food models may be used as memory aids or to help

quantify serving sizes

� Intake calculated using food composition data


Estimated Food RecordEstimated Food Record

� Record food & beverage in a food diary – 1 to 7

days

� 3-4 day diaries usually include one week-end day

� Number of days depends on nutrients of

interest

� Quantities estimated in household measures



Weighed Food Record

� Used to assess actual or usual intake of individuals – depending on days recorded

� All food and plate waste is weighed

� Food samples may be saved for analysis

� Number of days depends on nutrients of interest


� GOLD STANDARD


Dietary HistoryDietary History

� Retrospective, with extensive interview

� 24 hr recall of actual intake + usual intake followed

by food frequency questions to verify & clarify

� Skilled interviewer (dietitian)

� Collects dietary intake over past 1-3 mo’s (usually)

� Info on intake patterns, beliefs and habits

� Used in diet assessment in clinical practice

� Intakes calculated using food composition data


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Food Frequency QuestionnaireFood Frequency Questionnaire

� Extensive questionnaire/list of specific food items

� Records intake over given period (day, week, month, year)

� Asks about a wide range of foods

� Self administered or interview

� Can be designed for nutrient specific questions

� Intakes calculated using food composition data


1.On average, how many servings of breakfast cereal do you consume per

week? (Please mark one only)

(A ‘serving’ = 1 cup porridge or cornflakes or ½ cup muesli or 2 weetbix).

E.g. 1 cup of porridge 3 times per week + 2 weetbix 4 times a week = 7 servings per week

Per Week

€None €< 4 servings

€4–6 servings€7–9 servings€10–12 servings

€13–15 servings

€≥ 16 servings

1.How often do you usually consume these foods?

FFQ - example

Breakfast Cereals

Please fill in one category foreach food Never

Less than

once a

month

1-3 times

per

month

Once per

week

2-4 times

per

week

5-6 times per

week

Once per day

2 or more times per

day

Porridge, rolled oats, oat bran,oat meal

Muesli (all varieties)

Weetbix (all varieties)

Cornflakes or rice bubbles

Bran based cereals (all varietiese.g. All Bran, Sultana Bran)

Light and fruity cereals (e.g.Special K, Light and Tasty)

Chocolate based cereals (e.g.Milo cereal, Coco Pops)

Sweetened cereals (e.g.Nutrigrain, Fruit Loops, HoneyPuffs, Frosties)

Breakfast drinks (e.g. Up & Go)

FFQ - example

Apparent Consumption /

qualitative assessment

Apparent Consumption /

qualitative assessment� Obtained from supermarkets, industry turnover

� Does not account for waste

� Rough estimate only

� Does not reveal who is eating what

� Impossible to determine individuals at risk

� In-depth descriptive content

� Supplementary to other techniques


Documents

Introduction - Nutrition Assessment July 2015