Transcript Assessing Nutritional status

Assessing Nutritional status
Dr. Shivananda Nayak
Faculty of Medical Sciences
The University of The West Indies
•The nutritional status of an individual is the result of many
interrelated factors
• It is influenced by food intake, quality, quantity and physical
health
• The spectrum of nutritional status spread from obesity to
malnutrition
1
Why Nutritional assessment required
It is required to:
 Develop health care programs which meet the
community needs which are defined by the
assessment
 Measure the effectiveness of the nutritional
programs and intervention once initiated
Methods of nutritional assessment
It is assessed by direct and indirect methods
2
The direct method
Deal with the individual and measure objective criteria
Summarized as ABCD
 Anthropometric methods
 Biochemical and laboratory methods
 Clinical methods
 Dietary evaluation methods
Indirect methods of nutritional assessments
 Uses community health indices that reflects nutritional
influences
These include
 Ecological variables including crop production
 Economic factors e.g. per capita income, population density
and social habits
 Vital health statistics particularly infant under 5 mortality and
fertility index
3
Clinical assessment method
 It is an essential feature of all nutritional
surveys
 Simplest and most practical method of
ascertaining the nutritional status of a group
of individuals
 It utilizes a number of physical signs that
are known to be associated with
malnutrition & deficiency of vitamins &
micronutrients
4
General clinical examinations, with special
attention to organs, like hair, nails, skin, gums,
eyes, muscles, tongue, angles of mouth and
thyroid gland
 Detection of relevant signs helps in
establishing the nutritional diagnosis

Advantages of Clinical assessment
 Fast and easy to perform
 Inexpensive
 Non-invasive
Limitations
 May not detect the early stages
5
Anthropometric measurements
•Anthropometry is the measurement of body weight
and proportions
•It is an essential part of clinical examination of
infants, children and pregnant woman
•It is also used to evaluate both under and over
nutrition
•The measured values reflect the current nutritional
status.
6
Other anthropometric measurements:
 Mid-upper arm circumference
 Head circumference
 Skin fold thickness
 Head/chest ratio
 Hip/waist ratio
Anthropometry for children
Accurate measurement of height and weight is necessary to
evaluate the physical growth of the child
Ht/Age:
 Height of index child compared with the expected weight of
a healthy child of the same age
 Measure of long term nutritional status or stunting
Wt/Ht:
Measure of wasting ie. Appropriate weight for given height 7
Mid Upper Arm Circumference:
 Measured half-way between the acromion process of
the scapula and the tip of the elbow (ulnar) with the
arm hanging vertically and forearm supinated
 Provides an estimate of Arm Muscle Area: reflect
skeletal protein reserves lean body mass useful in
monitoring vulnerable groups, especially children
Head Circumference:
 Useful in children under the age of 3 and is an
indicator of non-nutritional abnormalities. Under
nutrition must be severe to affect head circumference
8
Anthropometry for adults
Height measurement

The subject stands erect and bare footed on a stadiometer
with a movable head piece is leveled with skull vault and
height is recorded to the nearest 0.5 cm
Weight measurement



Use of regularly calibrated electronic or balanced-beam scale
is suggested to measure the weight.
During weight measurement wearing light clothes without
shoes is suggested
Read to the nearest 100 gm.
Skin folds
 Triceps, Biceps, Sub-scapular, Supra-iliac used in combination
to obtain body fat
9
Nutritional Indices in adults
 The international standard for assessing body size in
adults is the body mass index (BMI)
 BMI is computed using the following formula
BMI =
Weight (kg) kg/m2
Height (m2)
<18.5
= Underweight
18.5-24.9 = Normal Weight
25-29.9
= Overweight
30-34.9
= Moderate Obese
(Class 1)
35-39.9
= Severely Obese
(Class 2)

40
= Extreme Obesity
10
BMI = Weight (lbs) x 703
Height (in2)
<18.5
= Underweight
18.5-24.9 = Normal Weight
25-29.9
= Overweight
30-34.9
= Moderate Obese (Class 1)
35-39.9
= Severely Obese (Class 2)
40
= Extreme Obesity (Class 3)
High BMI (obesity level) is associated with type 2 diabetes and
high risk of cardiovascular morbidity and mortality
Waist/Hip ratio
 Waist circumference is measured at the level of the umbilicus to
the nearest 0.5 cm
 The subject stands erect with relaxed abdominal muscles, arms
at the side, and feet together
 The measurement should be taken at the end of a normal
expiration
11
Waist circumference
 Waist circumference predicts mortality better than
any other anthropometric measurement
 It has been waist circumference alone can be used to
assess obesity and two levels of risks have been
identified
Males
Females
Level 1
>94 cm
>80 cm
Level 2
>102 cm >88 cm
 Level 1 is the maximum acceptable waist
circumference irrespective of the adult age and there
should be no further weight gain
 Level 2 detects the obesity and requires weight
management to reduce the risk of type 2 diabetes
and cardiovascular complications
12
Hip circumference
 It is measured at the point of greatest circumference
around hips and buttocks to the nearest 0.5 cm
 The subject should be standing and the measurer
should squat beside him
 Both measurement should be taken with a flexible,
non-stretchable tape in close contact with the skin,
but without indenting the soft tissue
Interpretation of Waist/Hip Ratio (WHR)
 High risk WHR = >0.80 for females and >0.95 for
males i.e. waist measurement > 80% of hip
measurement for women and 95% for men indicates
central obesity and is considered high risk for
diabetes and cardiovascular disorders
13
A WHR below these cut-off levels considered low risk
Advantages of Anthropometry
 Simple, non-invasive.
 Equipment is inexpensive, portable.
 Relatively unskilled personnel can perform
measurements.
 Methods are reproducible.
 Measures long term nutritional history.
 Quickly identifies mild to moderate malnutrition.
 Measures many variable of nutritional significance
like height weight, skin fold thickness, head
circumference waist and hip ratio and BMI
14
Disadvantages of Anthropometry
 Relatively insensitive to short term nutritional status
 Cannot identify specific nutrient deficiencies
 Measurements: e.g.. Skin-folds difficult to carry out in obese
people
 Ethnic differences in fat deposition
Dietary assessment
 Nutritional intake of humans is assessed by five different
methods
 24 hour dietary recall
 Food frequency questionnaire
 Dietary history from the beginning
 Food dairy technique
 Observed food consumption
15
24 hour dietary recall
 A trained interviewer asks the subject to recall all
food and drink taken in the previous 24 hours
 It is quick, easy, and depends on short term
memory, but may not be truly representative of the
person’s usual intake
Food frequency questionnaire
 The subject is given a list of around 100 food items
to indicate his or her intake (frequency and
quantity) per day, per week and per month
 It is inexpensive, more representative and easy to
use
16
Dietary history
 It is an accurate method for assessing the nutritional
status
 The information should be collected by a trained
interviewer
 Details about the usual intake, types, amount,
frequency and timing needs to be obtained
 Cross-checking to verify data is very important
Food dairy
 Food intake should be recorded by the subject at
the time of consumption
 The length of the collection period range between 17 days
 It is reliable but difficult to maintain
17
Observed food consumption
 The most unused method in clinical practice (must
for research)
 The meal eaten by the individual is weighed and
contents are to be calculated exactly
 High degree of accuracy but expensive and needs
more time and efforts
Interpretation of dietary data
1.Qualitative method
 Using the food pyramid and the basic food groups
method
 Different nutrients are classified into 5 groups (fats
and oils, bread and cereals, milk products, meat-fishpoultry, vegetables and fruits
18
Determine the number of serving from each group and
compare it with minimum requirement
2. Quantitative method
 The amount of energy and specific nutrients in each food
consumed can be calculated using food composition tables
and then compare it with the recommended daily intake
 Evaluation by this method is expensive and time consuming,
unless computing facilities are available
Laboratory measurements
 Blood: accessible, relatively non-invasive reflect recent
dietary intakes but influenced by: diet; drugs; infection;
stress
19







Haemoglobin is the most important test and useful
index of the overall state of nutrition. Beside anaemia
it also gives idea about protein and trace element
nutrition
Stool examination: to detect the presence of ova and
intestinal parasites
Urine examination for albumin, sugar and blood
RBC vs WBC: gives idea about long/short term
nutrient status
Analysais of hair nails and skin for micronutrients
(Cu, Se, Zn, Hg,etc)
Detection of abnormal amount of metabolites in the
urine (creatinine/hydroxyproline ratio)
Functional tests done to study about the metabolic
pathways
20
Advantages of Biochemical Measurements
 It is useful in detecting early changes in body metabolism and
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
Disadvantages of Biochemical Measurements
 Expensive
 Time consuming
 Needs trained personal and facilities
Reference: Essentials of Biochemistry by
Dr S Nayak
21