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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
2
amount of food I eat.
 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 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.
Nutrition Assessment
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
How To Assess Nutritional Status?
Stages of deficiency
Inadequate food intake
Assessment method
Dietary evaluation
Impaired absorption, utilization or transport
Increased requirement, destruction or excretion
Decreased tissue levels
Biochemical &
Anthropometry evaluation
Altered physiology/biochemical functions
Biochemical evaluation
Signs & Symptoms of deficiency
Clinical evaluation
Methods of Nutrition Assessment
Anthropometric methods
Biochemical methods
Clinical methods
Dietary 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
Measure
1. variations of the physical dimensions (length, weight,
proportions)
2. gross composition (fat mass, fat-free mass)
of the human body at different age levels and degrees of
nutrition.
Jelliffe,1966
Nutritional Assessment Indices
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)
Body Mass Index
BMI =
Weight (in kilogrammes)
(Height)2 (in metres)
• 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
Body Mass Index
Underweight
Normal
Overweight
Obesity
BMI
(WHO)
BMI
(Asian)
BMI
(China)
<18.5
<18.5
<18.5
18.5 – 24.9
18.5 – 22.9
18.5 – 23.9
25 – 29.9
23 – 27.4
24 – 27.9
>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 & CVD
Waist Circumference (NIH): high risk in adult males > 102 cm
adult females > 88 cm (NIH)
Systems available
1. 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)
Anthropometry
Advantages
 Procedure
• Simple, safe, noninvasive
• 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
Limitations Of Physical Examination
☻ Non specificity of the physical signs
some may be produced by >1 nutrient deficiency or by nonnutritional 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
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
Measuring Food Consumption

Assessment methods provide qualitative or
quantitative information from food consumption
surveys

Data collected at:

National level

Household level

Individual level
Methods Of Dietary Assessment Of Individuals

24-hour recall method

Estimated food records

Weighed food records

Diet history

Food Frequency Questionnaire
24-hour Recall Method
 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
 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
Advantages
Limitations
 low respondent burden, high  reliance on memory  difficult
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


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
Food Record / Diary
 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
Estimated food records

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
Weighed food 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
Limitations
Advantages
 Does not depend on memory

Requires lots of co-operation
 Provides detailed intake data

Respondent burden  low
response rates

Subject must be literate
 Multiple-day data is more

Time-consuming
representative of usual
intake

Analysis is labor-intensive &
expensive

Act of recording may alter
diet
 Provides data about eating
habits
Diet History

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)
Advantages
 Assesses usual nutrient
intake
Limitations

Lengthy interview

Requires trained
interviewers

Difficult & expensive to
analyse

May over-estimate
nutrient intake

Requires respondent’s cooperation
 Can detect seasonal
changes
 Data on all nutrients
obtained
 Correlates well with
biochemical measures
Food Frequency Questionnaire
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
Simple/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 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 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 screeners 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
Limitations
Advantages
 can be self-administered
 may not represent usual foods or
portion sizes chosen by
respondents
 machine readable
 modest demand on respondents
 intake data can be compromised
 inexpensive for large sample sizes
when multiple foods are grouped
with single listings
 more representative of usual intake
than a few days of diet records
 depends on ability of subject to
 design can be based on large
population data
 Considered by some to be the method
of choice for research on diet-disease
relationships
describe diet
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
Uses Of Food Composition Tables

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
Limitations 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
Nutrient Analysis
a) Manual calculations
 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
composition table
 total
food
b) Computer 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
The Dietary Reference Intakes (DRIs)
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)
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
EAR
UL
RNI
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
Nutrient density
• 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
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
Nutrient Adequacy Ratio (NAR)
represents an index of adequacy for a nutrient based
on the corresponding RDA for that nutrient
NAR = 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
Standard deviation or Z score

a measure of an individual’s nutrient intake in
relation to the distribution of nutrient intakes of the
group
Average intake for

does not evaluate nutrient
intakes in relation to the
recommended nutrient
intakes

useful in longitudinal
studies
nutrient X
-2 SD
+2 SD
Intake values for nutrient X
Index of Nutritional Quality (INQ)
• 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
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
Evaluates intake of
various nutrients & food
components, assesses
consumption of foods &
food groups
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
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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