Nutrition Assessment

The science of determining nutrition status

1

Determine Your Nutritional Health

The warning signs of poor nutritional health are often overlooked. Use this checklist

to find out if you or someone you know is at nutritional risk.

I have an illness or condition that made me change the kind and/or

amount of food I eat.

2

I eat fewer than 2 meals per day. 3

I eat few fruits or vegetables, or milk products. 2

I have 3 or more drinks of beer, liquor or wine almost every day. 2

I have tooth or mouth problems that make it hard for me to eat. 2

2

I don't always have enough money to buy the food I need. 4

I eat alone most of the time. 1

I take 3 or more different prescribed or over-the-counter drugs a day. 1

Without wanting to, I have lost or gained 10 pounds in the last 6 months. 2

I am not always physically able to shop, cook and/or feed myself. 2

SCORES: 0–2 = good; 3–5 = moderate nutritional risk; 6 or more = high nutritional risk.

The Determine checklistThe Determine checklist, is based on these warning signs of poor nutrition:

Disease

Eating poorly

Tooth loss, mouth pain

Economic hardship

Reduced social contact

Multiple medicines

Involuntary weight loss or gain

Need for assistance in self-care

Elderly (age > 80)

The Nutrition Screening Initiative, a project of the American Academy of Family Physicians, the American Dietetic Association and the National Council on Aging, Inc., and funded in part by a grant from Ross Products Division, Abbott Laboratories.

is a comprehensive approach completed by a registered

dietitian for defining nutritional status using medical, social,

nutritional and medication histories, physical examination,

anthropometric measurements and laboratory data.

The American Dietetic Association,

Council on Practice, 1994

Nutrition Assessment

How To Assess Nutritional Status?Stages of deficiency

Inadequate food intake

Impaired absorption, utilization or transport

Decreased tissue levels

Altered physiology/biochemical functions

Signs & Symptoms of deficiency

Dietary evaluation

Biochemical & Anthropometry evaluation

Clinical evaluation

Biochemical evaluation

Assessment method

Increased requirement, destruction or excretion

Methods of Nutrition Assessment

A

B

C

D

nthropometric methods

iochemical methods

linical methods

ietary methods

Can be used alone, but more effectively in combination to provide an accurate picture of an individual’s nutrition status;Not based on a single determination but on a group or series of measurements & observations.

Nutritional Anthropometry

MeasureMeasure

1. 1. variations of the physical dimensions variations of the physical dimensions (length, weight,

proportions)

2. 2. gross composition gross composition (fat mass, fat-free mass)

of the human body at different age levels and degrees of of the human body at different age levels and degrees of

nutrition.nutrition.

Jelliffe,1966

Constructed from 2 or more raw anthropometric measurements & are ratios.

E.g. • Head circumference-for-age• Height-for-age• Weight-for-age• Weight-for-height• Weight changes

A very widely used height -weight index is body mass index (BMI)

Nutritional Assessment Indices

Body Mass Index

• For adults >20 yrs (not for pregnant / lactating )

• high correlation with estimates of body fatness, a reliable indicator of obesity (adjusted by sex, race and age)

• At the same BMI, female tend to have more body fat than male.

• At the same BMI, older people, on average, tend to have more body fat than younger adults.

• Does not distinguish excess fat from muscularity as the source of excessive body weight, so

• Highly trained athletes may have a high BMI because of ↑ muscularity rather than ↑ body fatness.

• For children 2-20 years, use BMI for age

Weight (in kilogrammes)(Height)2 (in metres)

BMI =

Body Mass Index

BMI (WHO)

BMI (Asian)

BMI (China)

Underweight <18.5 <18.5 <18.5

Normal 18.5 – 24.9 18.5 – 22.9 18.5 – 23.9

Overweight 25 – 29.9 23 – 27.4 24 – 27.9

Obesity >30 >27.5 >28

Evaluating Indices & Data Of Nutritional Assessment

Classification: “at risk” or “not at risk”

E.g. disease risk for type 2 diabetes, hypertension & CVDWaist Circumference (NIH): high risk in adult males > 102 cm adult females > 88 cm (NIH)

Systems available1. Reference limits from appropriate reference data: “at risk” of

malnutrition

• 2 SD above & below median reference data• below 3rd / 5th percentiles or above 97th / 95th percentiles (e.g.

growth charts)

2. Cut-off points E.g. WHO cutoff points for anemia (Hb < 120 g/L)

AnthropometryAdvantages Procedure

• Simple, safe, non-invasive

• Applicable to large sample size

Equipment – portable, inexpensive

Unskilled personnel/minimal training

Evaluate changes in nutritional status over time

Limitations

Insensitive – cannot detect

disturbance over short

periods of time

Unable to distinguish

between specific nutrient

deficiencies

Lack of appropriate

standards to compare

results

Biochemical Assessment

Lab measurements done on available body tissues, usually blood or urine

Measures

Nutrients

Nutrients metabolites

Substances that contain the nutrient (e.g. Hb for iron)

Enzymes that require the nutrient (e.g. transketolase for thiamin)

Substances that result from abnormal metabolism from a deficiency of the nutrient (e.g. elevated pyruvate levels in thiamin deficiency)

Biochemical Assessment

Provide the most objective and quantitative data on nutritional status

Can detect sub-clinical deficiency = uncovers early signs of malnutrition before alterations in anthropometric measures or clinical signs/symptoms of a deficiency disease appear

Sufficiently accurate to use as a validation method in dietary surveys

May be influenced by non-nutrition factors like disease or medication use

Clinical Assessment

Clinical Assessment

Consists of a routine medical history + nutrition-focused

physical examination

to detect signs and symptoms associated with malnutrition

Most useful during advanced stages of nutritional depletion,

usually when overt signs already present

Many physical signs are non-specific

need to interpret together with laboratory, anthropometric

and dietary data to identify the specific nutritional deficiency

☻ Non specificity of the physical signs

some may be produced by >1 nutrient deficiency or by non-nutritional factors

☻ Multiple physical signs

may exhibit multiple physical signs due to co-existing nutrient deficiencies confusion

☻ Signs may be two-directional

occur during the development of a deficiency and/or recovery

☻ Examiner inconsistencies

bias

Limitations Of Physical Examination

Dietary Assessment

To determine an individual or population’s usual dietary intake

To identify potential dietary inadequacies

To provide data on intake of nutrients or specific classes of food

Involves surveys:

measures quantity of individual foods consumed in one to several days

assesses the pattern of food used during the previous several months

Assessment methods provide qualitative or

quantitative information from food consumption

surveys

Data collected at:

National level

Household level

Individual level

Measuring Food Consumption

Methods Of Dietary Assessment Of Individuals

24-hour recall method

Estimated food records

Weighed food records

Diet history

Food Frequency Questionnaire

Subjects (their parents or caregivers) are asked to recall exact food intake

during the previous 24 hour period

Detailed description of all foods & beverages consumed, including cooking

methods and brand names (if possible) are recorded

Quantities of foods consumed are usually estimated in household measures

Photographs, food models & utensils of various types can be used as

memory aids and/or to assist in assessing portion size

The interviewer records the information for later coding and analysis

24-hour Recall Method

Conducted in 4 stages using a standardised protocol

1) recall of foods and drinks consumed

2) description of foods and drinks consumed

3) estimation of amounts – food models

4) review of interview data

24-hour Recall Method

Success depends on:

subject’s memory

ability of the respondent to convey accurate estimates

of portion size consumed

degree of motivation of the respondent

persistence of the interviewer

low respondent burden, high compliance

low cost

ease and speed of use

its administration does not alter the usual diet

can provide detailed information on types of food consumed

ideal for illiterate respondents

can be used to estimate nutrient intake of groups

reliance on memory difficult for the elderly and young children

estimation errors of food portion sizes occur (can be reduced by using graduated food models)

one recall is seldom representative of a person’s usual intake

over-report low intakes & under-report high intakes

withold/alter information because of embarrassment

data entry can be labour intensive

Advantages Limitations

The respondent records, at the time of consumption, the

identity and amounts of all foods and liquids consumed

Period of time usually 3 - 7 days

Includes information on time, place and situation of eating

Food Record / Diary

Record - time of consumption for each food

Detail description - brand names, method of preparation

Composite dish - raw ingredients, final weight of dish

Portion size – in household measurement

Convert to gram for analysis

EstimatedEstimated food recordsfood records

Most precise – requires weighing scale

Weigh all foods and beverages consumed by the subject

Details - preparation, brand names

Method is same as estimated food records except the weighing

Weighed food recordsWeighed food records

Does not depend on memory

Provides detailed intake data

Provides data about eating

habits

Multiple-day data is more

representative of usual

intake

Requires lots of co-operation

Respondent burden low

response rates

Subject must be literate

Time-consuming

Analysis is labor-intensive &

expensive

Act of recording may alter

diet

Advantages Limitations

A detailed dietary assessment

Assess individual’s usual dietary intake over extended period of time

(past month or year)

Burke’s original method involved 4 steps:

General info about health habits – smoking, exercise, appetite, use

of supplements, food dislikes, intolerances, weight history etc

24 hr recall - actual intake and general information on the overall

eating pattern

Cross check on data with specific questions about

preferences/habits e.g. diet changes

3-day food record (additional means to check the usual intake,

many omit this step)

Diet History

Assesses usual nutrient

intake

Can detect seasonal

changes

Data on all nutrients

obtained

Correlates well with

biochemical measures

Lengthy interview

Requires trained

interviewers

Difficult & expensive to

analyse

May over-estimate

nutrient intake

Requires respondent’s co-

operation

Advantages Limitations

Assesses energy/nutrient intake by determining how frequently a

person consumes a limited number of foods that are major sources

of the nutrient in question

Questionnaire consist of a list of individual food/good groups that are

important contributors to the population’s intake of energy and

nutrients

Respondents indicate how many times a day/week/month/year they

consume the foods

Food Frequency Questionnaire

Simple/non-quantitative formatSimple/non-quantitative format

• Choice of portion sizes not given, generally use ‘standard’ portion sizes –

the amount customarily eaten per serving for various age/sex groups

• E.g. how many times one eats dark bread or ice cream

Semi-quantitative formatSemi-quantitative format

• Gives respondent an idea of portion sizes

• E.g. how many times one eats a slice of dark bread or ½ cup serving of ice

cream

Quantitative formatQuantitative format

• The respondent needs to describe the size of his/her usual serving as small,

medium or large relative to a standard serving

• The information is then entered into a database which multiples the

nutrients content and arrives at an estimated nutrient intake

FFQs known as screenersscreeners have been developed to assess intake of

calcium, dietary fiber, fruits and vegetable, and percent energy

from fat.

Useful in situations that do not require assessment of the total diet

or quantitative accuracy in dietary estimates or when financial

resources are limited

Commonly used in epidemiologic research investigating the

relationship between diet and such conditions as cancer or CVD

Can be self-administered and machine readable – cost effective for

measuring diet in large epidemiologic studies

can be self-administered

machine readable

modest demand on respondents

inexpensive for large sample sizes

more representative of usual intake

than a few days of diet records

design can be based on large

population data

Considered by some to be the method

of choice for research on diet-disease

relationships

may not represent usual foods or

portion sizes chosen by

respondents

intake data can be compromised

when multiple foods are grouped

with single listings

depends on ability of subject to

describe diet

Advantages Limitations

Food Consumption Data

To calculate nutrient intakes of individuals or population

groups if quantitative methods were used to collect data

Calculation of nutrient intakes:

Manual calculations using food composition tables

Computer calculation using nutrient databases stored in

computer

Nutrient data banks or computer-stored nutrient databases are

from food composition tables transferred to and maintained on

a computer

Food Composition Tables

Printed tables contain lists of thousands of foods with the

quantities of each nutrient (values) in a standard amount

(e.g. 100g) for each food

Nutrient values are based on a quantitative analysis of

samples of each food

Data is representative of the average composition of a

particular foodstuff on a year-round, nationwide basis

Values expressed in terms of the nutrient content of the

edible portion of the food per 100g and /or per common

household measures

To compare the nutritive value of one food with another

To calculate nutritive value of any diet so as to compare that

diet with the RDA

To plan diets that must meet specific requirements e.g.

250mg sodium or 100g protein, etc

To provide a ready reference to answer questions that

people ask about foods. Proper use of

the tables can counteract much nutritional

misinformation

Uses Of Food Composition Tables

Errors in data

- random e.g. due to natural variability in the composition of the foods / processing techniques

-systematic e.g. sampling procedures or method of analysis of the foods

Limited range of foods covered Recipe variations Effect of storage on nutrient content Incorrect/ambiguous description of individual food item e.g.

prawn paste, flat bread Inconsistencies in terminology used to express certain

nutrients

Limitations Of Food Composition Tables

select appropriate food composition table

record each type of food listed during the recall

calculate the edible portion : grams or household

measures

convert into decimal fraction

multiply the nutrient values from food

composition table

total

Nutrient Analysisa) Manual calculationsa) Manual calculations

Completeness depends on range of listed food &

availability of nutrient values

Steps

• select appropriate database / nutrient

• calculate edible portion consumed

• enter data

• check input data for transcription errors

• total, averages & comparisons to RDAs can be

displayed

b) Computer calculationsb) Computer calculations

Reference values that are quantitative estimates of

nutrient intakes to be used for planning and assessing

diets for apparently healthy people

The Dietary Reference Intakes (DRIs)

The Dietary Reference Intakes (DRIs)

Include 4 reference intakes

EAR

NRI

AI = adequate intake, an observational standard that is used when

insufficient data is available to determine RDA

UL = tolerable upper intake level, highest level of daily nutrient intake that

is likely to pose no risk of adverse healthy effects to almost all apparently

healthy individuals in the general population

EARRNI

UL

Safe range of intake

USES FOR AN INDIVIDUAL FOR A GROUP

ASSESSING

INTAKES

OF APPARENTLY HEALTHY INDIVIDUALS &

GROUPS

EAR : use to examine the probability that usual intake is inadequate

RDA & AI : usual intake at or above this level has a low probability of inadequacy

UL : usual intake above this level may place an individual at risk of adverse effects from excessive nutrient intake

EAR : use to estimate prevalence of inadequate intakes within a group

RDA : do not use to assess intakes of groups

AI : mean usual intake at or above this level implies a low prevalence of inadequate intakes

UL : use to estimate the % of the population at potential risk of adverse effects from excessive nutrient intake

Indices of Diet Quality

• Refers to a food’s vitamin & mineral content relative to its energy content i.e. a nutrient dense food is one that is a good source of vitamins & minerals but relatively low in energy

• Expressed as the amount of a nutrient per 1000kcal• E.g. the deep fried broccoli will have many of the same vitamins & minerals

as the steamed one but the sauces & oil will add extra calories

• Nutrient density allows easy & quick evaluation of quality of foods & diets independently of serving size

Nutrient densityNutrient density

High nutrient dense foods Low nutrient dense foods

Broccoli, steamed, served with lemon wedges

Broccoli, batter-dipped, deep fried served with cheese sauce

Milk, nonfat, plain Milk, whole, plain

Potato, baked Potato, French fried

represents an index of adequacy for a nutrient based on the corresponding RDA for that nutrientNAR = subject’s daily intake of a nutrient

age-specific RDA of that nutrient

Example: Sally, a 15 year old teenager, has an average daily intake of 12 mg iron. The RNI for iron for teenage girls (14-16 years) is 18 mg/day.NAR = 12/18 = 0.67

Mean adequacy ratio = sum of NARs for all evaluated nutrients divided by the number of nutrients evaluated. A composite indicator for micronutrient adequacy, allows evaluation of overall adequacy of selected nutrients in the diet. Nutrient intake considered adequate if NAR > 0.67

Nutrient Adequacy Ratio (NAR)Nutrient Adequacy Ratio (NAR)

a measure of an individual’s nutrient intake in relation to the distribution of nutrient intakes of the group

does not evaluate nutrient intakes in relation to the recommended nutrient intakes

useful in longitudinal studies

Standard deviation or Z scoreStandard deviation or Z score

Average intake for nutrient X

+2 SD-2 SD

Intake values for nutrient X

• INQ = nutrient per 100 g food / RDA for the nutrient

energy per 100 g food / energy requirement

Example: Is egg or cheddar cheese a better source of protein?

Data: 100 g cheddar cheese has 25 g protein, 403 kcal

100 g eggs has 12.4 g protein, 141 kcal

For ♂ 18-30 years, NRI for protein = 65g, energy = 2100 kcal/day)

INQ (egg) = 12.4/65 INQ (c cheese) = 25/65

141/2100 403/2100

= 2.84 = 2.00

Index of Nutritional Quality (INQ)Index of Nutritional Quality (INQ)

INQ = 1 indicates that the food is an adequate source of the nutrient

INQ = 2-6 indicates that the food is a good source of the nutrient

INQ > 6 indicates that the food is an excellent source of the nutrient

→Both are good sources of protein, with eggs first, second cheddar

cheese

• Excellent rating for a single nutrient does not reflect equivalent

rating for other nutrient

Diet Quality Index (DQI)Diet Quality Index (DQI)10 indicators of quality Scoring Criteria

Total fat < 30% energy intake < 30% = 10 points, 31-40% = 5 points, > 40% = 0 points

Sat fat < 10% energy intake < 10% = 10 points, 11-13% = 5 points, > 13% = 0 points

Dietary cholesterol < 300 mg/day

< 300 mg = 10 points, 300-400 mg = 5 points, > 400 mg = 0 points

2-4 servings of fruit/day 10-0 points, proportional to % of recommended servings

3-5 servings of vegie/day

6-11 servings of grains/day

Calcium intake as % of AI 10-0 points, proportional to % of AI or RDA

Iron intake as % NRI

Dietary diversity score 10-0 points, proportional to consumption of food across 23 food group categories

Dietary moderation score 10-0 points, based on intake of added sugars, discretionary fat, sodium & alcohol in excess of recommended levels of intake

Evaluates intake of various nutrients & food components, assesses consumption of foods & food groups

Overall Evaluation

comparison of individual intakes with tables of

recommended nutrient intakes

comparison of individual food habits in relation to the

nutrition guidelines

Dietary data alone can estimate the risk for nutrient

inadequacies

Anthropometric, biochemical and clinical assessments

carried out with dietary investigation to identify

nutrient deficiency

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