Nutritional Assessment METHOD POWER POINT.ppt

HEALTH DOING

1. Nutritional
Assessment
For MPH students
Haile.B

2. Definition
Nutritionalassessmentisaninterpretationof
anthropometric,biochemical(laboratory),clinical
anddietarysurveydatatotellwhetheraperson/
groupofpeopleiswellnourishedormalnourished
(Overnourishedorundernourished).
Therearedirectandindirectmethods of
assessingNutritionalstatus.

3. DIRECT METHODS
Thedirectinvolvethedirectmeasurementof
body dimensions and proportions,
determinationoftissueorbodyfluid
concentrationsofnutrients,dietaryintake,
appearanceoftheclinicalsymptomsand
signsrelatedtoaspecificnutrient
dependent functional impairment
abbreviatedastheABCDs
A=Anthropometry
B=biochemical/Biophysical,
C=Clinical,
D=Dietary

4. The indirect methods #1
Indirectmethods includeassessmentof
indicatorsofthefoodandnutritionsituations
inthearea/regionofinterestbylookingat
certaindatathatarecloselyrelatedto
malnutritionorwhichareaggravatedby
malnutrition.Theseinclude:
Causespecificmortalityrates
Agespecificmortalityrates
Healthservicestatistics
Rateofnutritionallyrelevantinfections

5. The indirect methods #2
 Meteorologicaldata(rainfalldata)
 Productionpatternanddistribution
pattern
 Incomelevels
 Marketpriceoffoods
 Predominanceofcashcrops

6. A. ANTHROPOMETRIC
ASSESSMENTS #1
Anthropometry comes from two Greek
words: Anthropo = Human, and
Metry/metron = measurement.
Definition: -Anthropometry refers to
measurement of variations of physical
dimension and gross composition of
human body at different levels and
degrees of nutrition (Jelliff, 1966).

7. ANTHROPOMETRIC ASSESSMENTS
#2
Anthropometric measurements could be used
both in the clinical and field set-ups. In the
clinical set-ups they are used to assess the
nutritional status of:
post-operative patient,
post traumatic patient (after acute trauma
or surgery),
chronically sick medical patient,
patient preparing for operation,
severely malnourished patient to assess the
impact of nutritional intervention.

8. Purposes of Anthropometric
measurements
Anthropometric measurements are
performed with two major purposes in
mind:
IN CHILDREN : to assess physical
growth
IN ADULTS: to assess changes in
body composition or weight

9. ANTHROPOMETRIC
MEASUREMENTS OF GROWTH #1
Growthperformanceofchildrenis
anexcellentreflectionoftheir
underlyingnutritionalstatus.
Childrenadapttothechronic
nutritionalinsultbyeitherreducing
theirrateofgrowthorbytotally
failingtogrow.

10. ANTHROPOMETRIC
MEASUREMENTS OF GROWTH #2
•Therefore,assessmentofgrowth
performanceofchildrenisonevery
importantpurposeofanthropometric
measurements.
•Thefollowingbodymeasurements
aregoodindicatorsofgrowth
performanceofchildrenatdifferent
ageswhencombinedwiththecut-off
points.

11. HEAD CIRCUMFERENCE
(HC):
Measuredusingflexiblemeasuringtape
around0.6cmwidetothenearest1mm.
Itisthecircumferenceoftheheadalong
thesupraorbitalridgeanteriorlyand
occipitalprominenceposteriorly.
HCisusefulinassessingchronicnutritional
problemsinundertwochildren.
Butafter2yearsasthegrowthofthebrain
issluggishitisnotuseful.

12. LENGTH
Awoodenmeasuringboard(alsocalled
slidingboard)isusedformeasuring
length.
Itismeasuredinrecumbentpositionin
children<2yrsoldtothenearest1mm.
Itisalways>heightby1-2cm.
Oneassistantisneededintakingthe
measurement
Measurementisreadtothenearestmm

13. Length…

14. HEIGHT
Ismeasuredinchildren>2yrsandaadultsin
standingpositiontothenearest0.1cm.
TheheadshouldbeintheFrankfurtplaneduring
measurement,kneesshouldbestraightandtheheels
buttocksandtheshouldersblades,shouldtouchthe
verticalsurfaceofthestadiometer(anthropometer)
orwall.
Stadiometerorportableanthropometercanbeused
formeasuring.
Thereisalsoaplasticinstrumentcalledacustat
Stadiometerthatischeaperthantheconventional
Stadiometer.

15. Height…

16. WEIGHT
Weighingsling(springbalance)also
calledsalterscaleisusedfor
measurementofweightinchildren<2
years.
Inchildrenthemeasurement is
performedtothenearest10g.
Inadultsandchildren>2years,beam
balanceisusedandthemeasurementis
performedtothenearest0.1kg.

17. Weight…

18. Improvising Weight measurement…

19. INDICES DERIVED FROM THESE
MEASUREMENTS
What isanindex? Itisa
combinationoftwomeasurements
orameasurementplusage.The
followingarefewofthem:-
Headcircumference-forage
Weight-for-age
Height-forage
Weightforheight

20. MEANINGS OF THE INDICES DERIVED
FROM GROWTH MEASUREMENTSWeight for Age = Weight of the child x 100
Weight the normal child of
the same age

Weigh for height = Weight of the child x 100
Weight of the normal child of
the same height


Height for age = Height of the child . X 100
Height of the normal child of
the same age

21. both weigh for age and weight for height
are indices sensitive to acute changes to
nutritional status
Height for age of children in a given
population indicates their nutritional status
in the long run.
The best example is change in the average
height of children in the industrialized
countries towards higher values following
improvements in nutrition, control of
infectious problems etc.
This is called Secular change (trend) in
Height

22. Indicator
An indicator is an index + a cut-off
point.
E.g.
W F A < 60% = is indicator of severe
malnutrition
MBI < 16 kg/m2 = indicator of severe
chronic energy deficiency
W F H < 70% = is indicator of severe
wasting

23. EXPRESSING ANTHROPOMETRIC
MEASUREMENTS #1 A. Z- score which is expressed as,
Z = median of the reference population---subject’s value X100
Standard deviation of the reference
-2 Z is a cut-off point for under nutrition

B. Standard deviation score which could be expressed as,
SD =(subject’s value -- the mean of the group)
2

Number of subjects—1
- 2 SD if a cut-off point for under nutrition

24. EXPRESSING ANTHROPOMETRIC
MEASUREMENTS #2C. Percent of the median expressed as,
P = Weight or height Value of the subject X 100
(Median height or weight value of the reference of the same age)
80 % of the median is a cut-off point for under nutrition

D. Centiles, Expressed according to the value of the subject in reference to
the NCHS’s 3
rd
,
5tyh, 10
th
and 90
th
centiles
Usually the 3
rd
centiles is taken as a cut off point for labeling
malnourished
subject.

25. Relationship of conventional cut -off points for
diagnosing moderate malnutritionType of
standard
Height for
age
Weight for
height
Weight for
age
Z-score -2 -2 -2
Standard
deviation
-2 -2 -2
Centile 3
rd
3
rd
3
rd

Percent of the
median
90% 80% 80%

26. We use SD in Ethiopia

27. Using appropriate methods
for different setups #1
•Percentiles are not recommended for
evaluating anthropometric measurements
from less developed countries when
reference data from industrialized
countries such as NCHS are used
•Because many of the study population may
have indices below the extreme percentiles
of the reference population making it
difficult for accurately classifying large
number of individuals

28. Using appropriate methods
for different setups #1
•Standard deviation score is recommended by
waterlow et al(1977) for evaluating
anthropometric data from less industrialized
countries.
•This is because the deviations scores can be
defined beyond the limits of original reference
data.
•This allows accurate classification of individuals
below the extreme percentiles of the reference
data.

29. CLASSIFICATION OF
NUTRITIONAL STATUS
BASED ANTHROPOMETRIC
INDICES

30. I. Gomez classification (weight-for-age)
(Gomez et al, 1956)
Percentage (%) of
NCHS reference
Levelofmalnutrition
90-109 Normal
75-89 Mild(grade I)
60-74 Moderate(Grade
II)
< 60 Severe (grade III)

31. Disadvantages of Gomez
classification
Thecutoffpoint90%maybetoohighasmany
well-nourishedchildrenarebelowthisvalue,
edemaisignoredandyetitcontributestoweight
and
Itdoesnotindicatethedurationofmalnutrition
ageisdifficulttoknowindevelopingcountries
(agrariansociety).
Itdoesnotalsodifferentiatebetweenkwashiorkor
andmarasmus

32. Well-come classification (weight-for-
age)
(Welcome trust working party 1970 )Level of malnutrition Percentage (%) of NCHS
Reference Edema No edema
60-80% Kwashiorkor Undernourished
< 60% Marasmic- kwashiorkor Marasmus

33. Disadvantages
This method does not differentiate :
Acute malnutrition (for emergency
planning
Chronic malnutrition( for food security
planning)
Depends on knowledge of the child’s
age
Does not take height differences in to
account

34. Waterlow Classification
( Waterlow JC,1972)

35. ASSESSMENT BODY COMPOSITION
#1
Linear growth ceases at around the age
of 25-30 years.
Therefore, the main purpose of
nutritional assessment of adults using
Anthropometry is determination of the
changes of body weight and body
composition.

36. Five levels of body
composition Assessment
1.Atomic level(C, H, N, P, Ca, O)
2.Molecular level(fat, Water, protein)
3.Cellular level(body cell mass,
intra/extra cellular water,
intracellular solids)
4.Tissue level(adipose tissue, muscle,
bone)
5.Whole body level(Weight, height,
skin folds)
wang et al

37. Some of the main components at the first
four body composition levels

38. Body composition levels & relevant
measurement methods

39. Pea Pod

40. Bod Pod

41. Bod Pod

42. Bioelectrical Impedance

43. ASSESSMENT BODY COMPOSITION
Using Anthropometry
Wholebodylevelassessmentisused
Inassessingbodycompositionwe
considerthebodytomadeupoftwo
compartments:
Thefatmassandthefatfreemass.Total
bodymass=Fatmass+fatfreeMass.
Thereforedifferentmeasurements are
usedtoassessthesetwocompartments:

44. Measurements used for assessing
fat free mass:
Midupperarmcircumference***
MidupperarmMusclearea
Midthighcircumference
Midthighmusclearea
Midcalfcircumference
Midcalfmusclearea

45. Mid upper arm circumference
(MUAC)
Isusedforscreeningpurposesespeciallyin
emergency situationswherethereshortageof
humanresource,timeandotherresourcesasitis
lesssensitiveascomparedtotheotherindices.
Itismeasuredhalfwaybetweentheolecranon
processandacromionprocessusingnonstretchable
tap
Inchildrenthecut-offpointsare:
Normal>13.5cm
Mildtomoderatemalnutrition12.5-13.5cm
Severemalnutrition<12.5cm
***Thesecut-offscouldbearbitrarily
modifiedbasedonavailableresources

46. The following cut-offs are used In community
Based Nutrition (CBN) programs of Ethiopia
Target
Groups
MUAC
Malnutrition
Under five
years old
children
11-11.9 cm
Moderate acute
malnutrition (MAM)
<11 cm
Severe acute
malnutrition (SAM)
Pregnant
women/
Adults
17 to <21cm
Moderate
malnutrition
18 to < 21 cm with recent
weight loss
< 17 cm
Severe malnutrition<18 cm with recent weight
loss

47. MUAC…
Itisasensitiveindicatorofrisk
ofmortality
Usefulforscreeningofchildren
forcommunitybasednutrition
interventions
Usefulfortheassessmentof
nutritionalstatusofpregnant
women

48. MUAC..

49. Measurements used to assess fat
mass :
Bodymassindex
WaisttoHipcircumferenceratio
Skinfoldthickness

50. Indices derived from the
measurements
Different indices could be derived by
measuring the weight and height of
an adult
Bodymassindex(Quetelet’sindex)
=Wt/(Heightinmeters)
2
Weight/heightratio(Benn’sindex)
P
Ponderalindex=Wt/(ht)
3

51. Body mass Index(BMI)
Body mass index the best method
for assessing adult nutritional status
as the index is not affected by the
height of the person
Therefore, it is most frequently used
for assessing adult nutritional status

52. Cut-off points for BMI
> 40 kg/m2 = very obese
30-40 kg/m2 = obese
26-30 kg/m2 = overweight
18.5-25kg/m2 = Normal
17-17.9 kg/m2 = mild chronic energy
deficiency
16-16.9kg/m2 = Moderate chronic
energy deficiency
< 16 kg/m2 = severe chronic energy
deficiency

53. This classification is based on the
mortalities and morbidities associated
with either extremities









The
Safe zone

Chronic diseases
(hypertension,
diabetes, cancer,
coronary heart
disease
Malnutrition
related
infections and
deficiency
diseases

Mortality
And
Morbidity
In %
16


18.5

25


30

40

Body mass index KG/M
2

54. Arm span and Demi-span
and Knee height #1
When it is not possible to measure
height as in the case of :
Elderly people
Kiphosis / Scoliosis
People unable to assume erect position
Height can be estimated from arm
span or demi-span

55. Arm span and Demi-span
and Knee height #2
•Arm span is the distance between the two
tallest fingers when a person stretches
his/her arm on straight line
•Demi-span is the distance between the
roots of the two tallest fingers when a
person stretches his/her arm on straight
line
•Knee height is the distance measured
from the heel to the top of the knee

56. Arm span and Demi-span
and Knee height # 3
Using a correlation equation it is
possible to estimate the height from
the measurements of arm span,
demi-span or knee height.
Y= a + Bx
Height = a + b(arm span) or
Height = a + b(Demi -span) or
Height = a + b(knee height)

57. Height(men)= 64.19 -(0.4Xage) + (2.02 X knee height)
Height(women)=84.88 -(0.24Xage) +(1.83 x knee height)
Estimating height from
knee height

58. SKIN FOLD THICKNESSES
#1
Skin fold thickness is a double foldof skin
and subcutaneous tissue done at the
following anatomical sights:
Biceps skin fold
Triceps skin fold
Subscapular skin fold
Suprailliac skin fold
Mid axillary skin fold
Thigh skin fold
Calf skin fold

59. SKIN FOLD THICKNESSES
# 2
•The measurement should be performed using
precision SFT calipers, which have a constant
and defined pressure of 10g/sq.mm
through out the range of measured skin folds.
•Other ordinary SFT calipers result in
underestimation of the subcutaneous fat as a
result of compression.

60. SKIN FOLD THICKNESSES
# 3
Skin fold should be read to the
nearest 0.5 mm after 2-3 seconds of
caliper application
Measurements are made in triplicate
until readings agree within ±1.0 mm
All the measurements should be made
on the left side

61. Precision skin fold
calibers
Someofprecisionskinfoldcalipers
are:
Lange(USA)measurestothe
nearest0.5mm
Holitain,Harpenden(UK)measures
tothenearest0.2mm
LowcostplasticMcgawcalipers
arealsoavailable

62. Calculating Body fat % from Skin fold
Thickness
The calculation of body fat % involves:
•Measuring four skinfold sites, triceps, biceps, subscapular and
suprailiac
•substitute the log of their sum into one of the following
equations, Where D = predicted density of the body (g/ml),
•L = log of the total of the 4 skinfolds (mm). The density value
can then converted toPercent bodyfat(%BF) using theSiri
Equation.
•We can also use body fat calculators
–http://www.health-calc.com/body-composition/skinfold-d-and-w

63. Body density calculations
age (years)equations for males
equations for
females
< 17 D = 1.1533 -(0.0643 X L)D = 1.1369 -(0.0598 X L)
17-19 D = 1.1620 -(0.0630 X L)D = 1.1549 -(0.0678 X L)
20-29 D = 1.1631 -(0.0632 X L)D = 1.1599 -(0.0717 X L)
30-39 D = 1.1422 -(0.0544 X L)D = 1.1423 -(0.0632 X L)
40 -49 D = 1.1620 -(0.0700 X L)D = 1.1333 -(0.0612 X L)
> 50 D = 1.1715 -(0.0779 X L)D = 1.1339 -(0.0645 X L)
L= log (sum of the skin fold thicknesses)

64. •Siri’s equation
% Body Fat = (495 / Body Density) -450

65. Cut-off for percentage of body fat
Description Women Men
Essential fat 10–13% 2–5%
Athletes 14–20% 6–13%
Fitness 21–24% 14–17%
"Average" 25–31% 18–24%
Obese 32%+ 25%+
Source: American Council on Exercise

66. WAIST TO HIP
CIRCUMFERENCE RATIO
Itisthecircumferenceofthewaist
measuredmid-waybetweenthelowest
ribcageandanteriorsuperioriliacspine
dividedbythecircumferenceofthehip
measuredatthelevelofthegreater
trochantoroffthefumer(bothare
measuredtothenearest0.5cm)
Iftheratiois>1inmale,and>0.87
infemalethereishighriskofcoronary
heartdisease.

67. Evaluation of nutritional
assessment induces
Nutritional assessment indices can be
evaluated by comparison with a distribution
of reference values or with the reference
limits drawn from the reference distribution
•Reference distribution( obtained from the distribution of
values of healthy reference sample group)
•Reference limits( The interval between and including them
being termed the reference interval eg. 5
th
and 95
th
, 3
rd
and 97
th)
•Cut-off points(based on the relationship between nutritional
assessment results and functional impairment and/ or clinical signs of
deficiency)

68. The concept of reference values
and relationship of recommended
termsReference individuals

Compose a

Reference population

From which is selected a

Reference sample group

On which are determined

Reference values

On which is observed

Reference distribution

From which are calculated

Reference limits

That may define

Reference intervals

69. Indicesbased on the WHO standards for preschool
children and the WHO reference for the older and
adolescents children

70. QUALITY CONTROL MEASURES IN
ANTHROPOMETRIC SURVEYS #1
The following issues need to be considered in
carrying out anthropometric surveys to ensure
the quality of data:
Calibration of the instrument after each
measurement and after moving the instrument
from one room to another.
Standardization of procedures.
Making subjects wear a uniform gown before
measuring weight or measuring their weight
nude if they are children.

71. QUALITY CONTROL MEASURES IN
ANTHROPOMETRIC SURVEYS #2
Verification of at least 10 % of the data by
the main investigator.
Training of the data collectors and limiting
the coefficient of variation to be less than
3%
(CV = standard /mean X 100).
Train observers by skilled professionals

72. QUALITY CONTROL MEASURES IN
ANTHROPOMETRIC SURVEYS #3
Use one rather than multiple observer for the
same subject over time.
Mark anatomic sites of measurement with
indelible ink when repeatedly measuring the
same subject over a short time span.
Periodically assess inter observer and
between-day measurement differences of
the staff.

73. Advantages and disadvantages of
Anthropometric measurements
Advantages Disadvantages
 Quick  Difficulty Of Selecting
Appropriate Cut-Off Points
 Cheap  Have Limited Diagnostic
Relevance (Only For Diagnosing
PEM)
 Objective  Need Reasonably Precise
Age In Children
 Gives Gradable
Results
 More Accepted By
The Community
 Non Invasive

74. Practical for Anthropometric
exercise
1.Each of you measure
•Height
•Weight
•Waist
•Heap
•Skin fold Thicknesses in triplicate and take the mean ( at
biceps, triceps, supra illiac, Sub scapular and mid maxillary
areas)
1. Calculate the waist to hip circumference ratio for yourselves
and evaluate it
2. Calculate the BMI for yourselves and evaluate it
3. Determine as to which measurement has resulted in higher
inter-observer variation and suggest quality control measures
2. Using a data set Calculate HAZ, WAZ, WFH, BAZ

75. B. BIOCHEMICAL/ BIOPHYSICAL
(LABORATORY) METHODS
•This involves measurement of either total amount of
the nutrient in the body, or its concentration in a
particular storage site (organ) in the body or in the
body fluids.
•This group includes those that are indicative of
defect in intermediary metabolism in other words
they occur when there is a biochemical lesion
(Depletion). The depletion could be detected
•by biochemical tests and/or by tests that measure
physiological or behavioral functions dependent on
specific nutrient.

76. 1) Static biochemical tests:-
Thisinvolvesmeasurementanutrientorits
metabolitesinpre-Selectedbiological
material(blood,bodyfluids,urine,hair,
fingernailsetc.)
Example, E.g. Biochemical Tests (laboratory)
1.Serum ferritin level
2.Serum HDL
3.Erythrocyte Folate
4.Tissue stores of Vit. A, Vit D,

77. Factors affecting the validity
of static biochemical tests
•Physiological factors(pregnancy, diurnal variation,
homeostatic regulation, physical exercise, age, sex, recent dietary
intake)
•Pathological(inflammatory stress, infection, weight
loss)
•Analytical(sample collection, sensitivity & specificity of the
test, hemolysis, sample contamination, acuracy and precision of
the method)

78. Functional biochemical tests
•These are diagnostic tests used to
determine the sufficiency of host
nutriture to permit cells, tissues, organs
or the host to perform optimally the
intended nutrient dependent biological
function
•Thesefunctionalbiochemicaltestsare
alsousefulfor:-
•Sub-clinicaldeficiencystates
•Basedonmeasurement offunctional
impairment

79. •Have greater biological value and
significance than static tests,
because they measure the extent of
functional consequence of a specific
nutrient deficiency.

80. Types of Functional Tests
•1.Abnormal metabolic products in
urine/blood: -vitamins and minerals act as
co-enzymes/prosthetic groups for enzyme
systems
•E.g. Vitamin B6 is a co-enzyme for
Kynureninase in the tryptophan -niacin
pathway.
•B6 def. decreased Kynureninase activity
Increased formation and excretion of
xanthuremic and kynuremic acids
•

81. Changes in enzyme
activities in the blood
2. This involves measuring a change in
the enzyme that is dependent on a
given nutrient.
•E.g. Lysl oxidase for copper
•Glutathion reductase for riboflavin
•Transketolase for thiamin

82. 3. Load and Tolerance Tests
Load Test #1
Load Test: This test is usually performed for
water-soluble vitamins.
The principle is that after loading a person
with a dose of the nutrient (vitamin) orally,
IM or IV. Then a timed sample of urine is
collected and excretion/retention level
assessed.
In carrying out this test it is assumed that
there will be increased retention of the
nutrient if the person is deficient of it and
vice versa.

83. 3. Load and Tolerance Tests
Load Test #2
Tolerance Test: This is also called plasma
appearance testand is performed based
on the assumption that there will be
increased absorption of the nutrient if the
person is deficient of it.
•E.g.: absorption of nutrients (Zn, Fe, and
Manganese) is increased in the deficiency
states.

84. 4. Invitro tests of in vivo function
E.g. Immunocompetence (cell
mediated immunity

85. 5. Spontaneous in vivo responses
This includes impairment of some body
functions resulting from deficiency of
a particular nutrient, E.g.
Capillary fragility in Vitamin C
deficiency
•Dark adaptation in Vitamin A
deficiency
•Taste acuity in zinc deficiency
•Muscle function in PEM

86. 6. Growth or developmental
responses
•Bothphysicalgrowthandmental
developmentareadverselyaffected
bythedeficiencyofmanynutrients.
•Thisismanifestedbyeitherfailing
to thrive or poor school
performances,laggingmilestonesof
developmentetc.
•E.g.Cognitivefunction=IRON

87. Others (Biophysical methods)
include: -
•Bone X-ray = calcium
deficiency
•Corneal impression cytology= Vit. A
•Buccal smear cytology = Vit.A
•Hair root morphology

88. Biomarkers Of Nutrients
(Laboratory Tests For Nutrients And Metabolites) #1Nutirient Most sensitive Less
sensitive
Least
sensitive
Protein
Plasma aminoacids,
transferrin, free alkaline
Rnase, urine 3-
methylhistidine

Serum
albumin,
urine
hydroxyproli
ne, urea,
creatinine
Total
serum
protein
Lipids
Serum high density
lipoproteins
Serum
cholestrol,
triglycerides
-
Vitamin A -
Serum
vitamin A,
retinol
binding
protein
-
Vitamin D
Serum25(OH)D 3,1,25(OH)2D3 Serum
alkaline
phosphatase
Seru
calcium
and
phospho
rus

89. Biomarkers Of Nutrients(Laboratory
Tests For Nutrients And Metabolites)
#2Nutirient Most sensitive Less sensitive Least
sensitive
Vitamin E
Serum
Tocoferol, H2O2
erythrocyte
fragility

Vitamin K
Serum
prothrombin
Bleeding and
coagulation
times

Vitamin c
Whole blood
ascorbic acid
Serum
ascorbic
acid
Thiamine
Erythrocyte
transketolase
and TTP effect
Urine thiamine Blood
pyruvate

Riboflavine
Erythrocyte
glutathion
reductase

Urine
riboflavine

90. Biomarkers Of Nutrients(Laboratory
Tests For Nutrients And Metabolites)
#3Nutirient Most
sensitive
Less sensitive Least
sensitive
NIacine

Urine N1 methyl
nicotinamide
and its
pyridone

Folic acid
Erythrocyte
folate
Serum folate Bone marrow
film, thin
blood film
Pyridoxine
Tryptophan
load test and
urine
thanturemic
acid, plasma
and urine
pyridoxine

Erythrocyte
glutamic,
puruvate and
oxalate
transaminase

91. Biomarkers Of Nutrients(Laboratory
Tests For Nutrients And Metabolites)
#4Nutirient Most
sensitive
Less sensitive Least
sensitive
Cyanocobalamin
Serum
vitamin B12,
Thymidylate
synthetase
Urine
methylmaloni
c acid
Bone
marrow
film, thin
blood
film

Iron
Serum
ferritin, iron
in bone
marrow
Serum iron
saturation,
transferrin

Blood
film
Iodine

T3, T4 Serum protein
bound iodine
Urine
iodine

92. ADVANTAGES AND
DISADVANTAGES OF BIOCHEMICAL
TESTS
Advantages
•Detect sub-clinical
Malnutrition
•Give gradable
nutritional
Information
•Are more objective
Disadvantages
•No ideal specimen or storage
site
•Many quality control problems
during sampletaking, carrying
out the test, analysis. Etc
•Some times low values may not
have any health Implication
•No ideal biomarker for each
nutrient
•Need sophisticated instruments
•Need highly trained staff
•Involve invasive procedures

93. C.CLINICAL METHODS #1
•This are detection of deviations from
the normal state of nutrition just by
observing and interpreting clinical
signs and symptoms of deficiency or
under intake, for instance, see the
following

94. CLINICAL METHODS #2Sign/ symptom Nutritional abnormality
Inability to see during the evening or dim
light (Night blindness also called nyctalopia)
Bitot’s spots
Vitamin A deficiency:
Easy bruising of skin
Spongy bleeding gums
Scurvy (vitamin C deficiency)
Pale: palms, conjunctiva, tongue
Easy fatigability, loss of appetite shortness
of breath
Anemia: Which may herald,
deficiency of: Iron, Vitamin
B12, Folic acid, copper,
protein (main causes of
nutritional anemia)

95. ii. DIETARY METHODS
•These methods include assessment of
past or current intakes of nutrients
from food by individuals or a group in
order to know their nutritional status.
•Atnationallevel:-
•FoodbalanceSheet
–alsocalledNationalfooddisappearance
dataor
–foodgoingintoconsumption
•Marketdatabases(forfortifiedfoods
byFDA)

96. Methods used to assess current intake
(at a group or individual level)
I.Weighedrecordmethod:Inthismethodthe
subjectwillbeaskedtoweighwhateverhe/she
consumesincludingdrinksbothbeforecooking
andaftercookingandtheportionsizeshe
consumedandtheleftover.
Advantages:
Itismoreaccurate
Thereisnorespondentmemoryloss
Disadvantages
Highrespondentburden
Changeofthedietaryhabitduringthesurveydue
fearofburden
Needsliterateandnumeraterespondents
Costly

97. ii. Observed weighed method
Inthismethodtheinvestigatorhim/herself
recordstheamountandtypeoffood
consumed bythestudysubjectsover
specifiedperiodoftime.
Thismethodisusuallyappliedfordisabled
people,infantsandsmallchildren,
mentallyillpeopleorinstitutionalized
elderlypeopleorpatientsadmittedtoa
hospital.
AdvantageVSdisadvantages
The same as the observed weighed

98. Food Diary method
•Inthismethodthesubject/sareaskedto
recordwhatevertheyeatincluding
beveragesforspecifiedperiodoftimewith
estimationoftheportionsizesconsumed.
•Advantage
–Maygiverelativelyaccurateestimateothe
nutrientintakeifdoneproperly
•Disadvantage
–Highrespondentburden
–Literacyandnumeracyofsubjectsneeded
–Highcodingburden

99. II. Methods Used to assess past
intake
24hoursdietaryrecall
•Inthismethod,thesubjectsarerequestedto
rememberwhatevertheyconsumedwithinthelast
24hours.
•Thisinvolvesallbeverages,snacksdesertsetc.That
havebeeningestedfromxtimeyesterdaytoxtime
today.
•Theportionsizesconsumedduringthistimeshould
alsobedeterminedbytherespondentsbyassessing
themtouseeitherphotographsorthecommonfood
beingconsumedatdifferentsizesorbyusingaline
graphetc.
•Currently-Multipass 24 hours is used to improve
the quality

100. Multiple-pass-24 hour recall
First Pass:Quick List
Second Pass:Detailed Description
Third Pass:amount consumed
Fourth pass: review

101. Repeated 24 hour dietary
recall #1
The number of days the recall has to be repeated is
determined by Nelson’s formula
D= r
2
x Sw
2
1-r
2
Sb
2
Where,
D = # of days of dietary data collection required
Sw= is within person variances of dietary intake
Sb = Between person variation of dietary intakes
r= correlation between the observed and true
mean
intake of individuals

102. Repeated 24 hour dietary
recall #2
For example, for poly unsaturated fatty acids the
Sw
2
/sb
2
= 3.5, If we want to get correlation of
between measured intake and true intake of 0.9,
how many days of data collection are needed?
D= r
2
x Sw
2
1-r
2
Sb
2
D= (0.9 x 0.9) X 3.5 = 14.9 =15 days
1-(0.9 x 0.9)

103. Reasons why a single day assessment
does not give the true mean intake
•Day of the week effect
•Seasonal effects
•Consecutive /nonconsecutive days
•Random within person variance
•Holiday effects(feasts and fasts)

104. Advantages and disadvantages
of 24 hrs dietary recall method
Advantages
Relativelycheap
Quick
Lessrespondentburden
No chance for the
respondentstochangetheir
dietaryhabit
Theusualintakeofagroup
canbedeterminedfroma
single24hrsrecall
Disadvantages
•Asingleday24hrsrecall
doesnotindicatetheusual
intakeofindividuals
•Respondentmemorylaps
•Socialdesirabilitybias(the
flatslopsyndrome)
•Has less precision
•Accuracy depends on the
respondent’s ability to
estimate portion sizes

105. Dietary history
Thismethodisusedtoassessthe
nutrientintakeofanindividualora
groupfromfoodoveralongerperiod
oftime,usuallytoseetheassociation
betweendietanddisease.

106. Advantages and
disadvantages of Dietary
history
Advantages
Itgivesthedietary
habitsofanindividualor
agroupofpeopleovera
longerperiodsoftime
Itispossibletotarget
thedietaryquestionsto
specificdietaryhabitsor
intake of specific
nutrientsofinterest
Lessrespondentburden
Disadvantages
Itoveremphasizesthe
regularityof the
dietarypattern
Itisverydifficultto
validate
Itneedsaveryhighly
trainedinterviewer
Itgivesjustarelative
ifnotanabsolute
information

107. Food frequency
questionnaire
•Thismethodisbasedonthepreparationofafood
frequencyquestionnaire,whichisbasedonthelocal
staplediettodeterminethefrequencyofconsumption
ofaparticularnutrient.
•Thiscouldbeachievedthroughselforinterviewer
administrationofthequestionnaire.
•Sometimes thequantitiesconsumed couldbe
included,insuchcircumstances,theFFQiscalled
semiquantitativeFFQ.
•Thefollowingtableindicatestheframeofafood
frequencyquestionnaire.

108. Example of semi quantitative FFQ
for Vitamin A friendly foodsFrequency of consumption
Food list
Daily
Every
other
day
Once
per
week
Once
per
month
Portion size
consumed
Carrot
Cabbage
Papaya
Mango
Cod liver oil
Liver

109. Advantages and
Disadvantages of FFQ
Advantages
•It is usually used for
areas where there is a
geographically widely
scattered study
population
•Itislesscostly
especially if self
administered
•Lessrespondentburden
Disadvantages
Itisverydifficultto
developespeciallyin
multi-culturalsociety
where different
staplefoodsare
consumed
Itneedsliterateand
numeratesubjects

110. Errors in dietary surveys
result from
•Interviewer bias
•Food tables
•Coding and computation errors
•Reporting errors
•Wrong weight of foods
•Wrong frequency of consumption
•Response bias( the flat slop syndrome or
memory laps)
•Sampling bias
•Change in dietary habit

111. Evaluation of Nutrient
intake data #1
•Foods can be converted into
nutrients using food composition
tablesor nutrient data banks
•Then the nutrient intake will be
compared to the RDAs(RNI) to
determine the adequacy of intake

112. Evaluation of Nutrient
intake data #2
•Calculating Nutrient adequacy
ratio(NAR) and Mean adequacy
ratio(MAR)
•NAR = Subjects daily intake of a nutrient
RDA of that nutrient
MAR = Sum of the NARs for X nutrients
X
NAR-represents an index of adequacy for a nutrient
MAR-Reflects an index of the overall quality of the diet

113. Stages of development of nutritional
deficiency
STAGE
DEPLETION STATUS METHOD OF
ASSESSMENT
One:
Dietaryinadequacy Dietary
Two:
Decreased levelin
thetissuereserves
Biochemical
Three:
Decreased levelin
thebodyfluids
Biochemical
Four:
Decreased
functionallevelin
thetissues
Biochemical
Five:
Decreasedactivityof
nutrientdependent
enzymes
Biochemical/Biophysi
cal
Six:
Functionalchanges Clinical/biophysical/
Anthropometric
Seven:
Clinicalsymptoms Clinical
Eight
Anatomicalsigns Clinical

114. Practical activity on Dietary
methods #1
•Determine your intake of the following nutrients over
the last 24 hours(protein, energy, calcium, Zinc,
magnesium, Iron, Vitamin A, Thiamin, Pyridoxine,
vitamin B12, ascorbic acid, folic acid and riboflavin)
•Compare each nutrient intake with your own RDAs
•Calculate :
–Nutrient Adequacy ratio for each of the above
nutrients for your 24 hours intake.
–Calculate the mean adequacy ratio of using the
above nutrients.

115. Practical activity on Dietary
methods #2
How many days of dietary data collection are required to get a
correlation of 0.9 between the true and and measured
intake using the following Sw
2
/sb
2
for males and females
?
Sw
2
/sb
2
Nutrient Male Female
•Iron 2.35 2.14
•Retinol 4.6 4.9
•Zinc 2.8 2.2
•Protein 1.3 1.7
•Energy 0.9 1.4
•Fat 1.3 1.5

116. Thank you !