2. WHAT IS NUTRITION ASSESSMENT?
The first step before planning and evaluating the
nutritional care of individuals or groups
Determined on the basis of multiple kinds of
information
A systematic method for obtaining, verifying &
interpreting information
3. Individual
Nutrition Assessment
Biochemistry
Energy
Anthropometry (Laboratory Clinical Dietary
Requirements
analysis)
Population
Assessment & Monitoring
Birth Monitoring
Food Household Mortality &
Food Anthropom wt, infant &
Supply & Dietary Morbidity
Prices etric Data feeding & Surveillanc
Data Surveys Data
mortality e System
5. ANTHROPOMETRY
Study of physical dimensions of the body
Standardised equipment & procedures essential
Body size
direct measurements
height, weight, circumferences
derived values
Body shape
Waist hip ratio, body weight distribution
Body composition
size of lean tissue and fat compartments
6. BODY MASS INDEX (BMI)
One of the most commonly used measurements for
assessing nutritional status
Ratio of weight to height
Caution – BMI not ideal for determining health risk
as it does not reflect amount of muscle compared to
fat
7. CLASSIFICATION OF OBESITY IN CAUCASIAN ADULTS
Classification # BMI (kg/m2) IBW % * Risk of Chronic
Disease
Underweight <18.5 >10% below* Low (but other
risks)
Normal range 18.5-24.9 desirable Average
Overweight >25
pre-obese 25.0-29.9 (10-19% above*) Increased
obese class I 30.0-34.9 (>20% above*) Moderate
obese class II 35.0-39.9 Severe
obese class III >40 Very severe
# WHO 2000, AIHW (2004)
* Ideal body wt (IBW) or desirable wt for ht (US Metropolitan Life Insurance data)
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8. OBESITY CLASSIFICATION - OTHER ETHNIC GPS
BMI classification in kg/m2
Asian Pacific Is.
<18.5 <19.9 Underweight
18.5-23.9 20.0 - 26.9 Normal
weight
24.0-26.0 27.0-32.9 Overweight
27.0-39.0 33.0-39.9 Obesity
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9. ANTHROPOMETRY - CIRCUMFERENCES
1. Waist circumference (AIHW, 2005) > 18 y
>94 cm (M) >80 cm (F) – abdominal
overweight
>102 cm (M) >88 cm (F) – abdominal
obesity
2. Waist: hip ratio
visceral fat around organs vs.
subcutaneous fat on hips
optimal WHR is < 1 (M) or < 0.8 (F)
varies with: genes, age, ethnicity, sex
increased by 'stress', smoking, alcohol
decreased by physical activity
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10. BIOCHEMISTRY
Blood tests
Readily obtained (so often used)
Vary little (homeostatic control)
Should be used in conjunction with nutrient and
supplementation history
Tissue testing
May include hair & nails for information about trace
elements
Other tissues only acceptable under exceptional
circumstances (invasive)
Urine testing
Varies between nutrients and influenced by variety
of factors (including volume of urine)
Multiple samples required
Functional tests
Ability to perform specific functions (e.g. muscle
response, immunological response)
11. BIOCHEMISTRY
Advantages:
Provide the earliest indications
of some nutrient deficiencies &
excesses
Relatively accurate & unbiased
(although not perfect)
Can provide evidence for a
nutritional diagnosis made on
the basis of signs & symptoms
Can be used to assess the
effect of some nutritional
therapy
12. CLINICAL
Information obtained includes:
Socio-demographic details (age, gender, occupation)
Medical history (including family history)
Medications
Physical functioning/activity
To help identify patients at risk of nutritional
deficiency, excess or requiring specialised nutrition
therapy
Signs & symptoms important
14. DIETARY INTAKE
Usual intake more informative than one day snapshot
Methods of measuring dietary intake include
Diet History
24hr recall
Food frequency questionnaire
Food diaries
Duplicate meals
Covered in week 3 lecture (last week)
Used to investigate quality of diet (core-foods) and energy
intake
15. ESTIMATING ENERGY - UNITS OF ENERGY
Unit of energy = the Calorie OR the Joule
Calorie is older unit of measurement
One calorie = the heat energy required to:
the temperature of 1g of H2O by 1 C
in Australia, we use kilojoules (kJ)
1 calorie = 4.18 kilojoules
http://www.youtube.com/watch?v=AA1mBek0gsQ
16. WHERE DOES ENERGY COME FROM?
Macronutrients in food
Carbohydrates (found in
breads, cereals, fruits, vegetables, dairy and snack
foods)
Protein (meat, eggs and dairy)
Fat (meat, full-cream dairy, snack foods)
Alcohol
Each macronutrient provides a different amount
of energy per gram (the value of energy
provided is termed the ‘Atwater factor’)
18. WHAT IS ENERGY DENSITY
To compare products we can calculate energy
density
Energy density = the amount of energy per
gram of food
Foods that have higher fat contents tend to
have higher energy density (e.g. take-away/
snack foods, fatty meats, fats & oils)
Foods that are low in fat but have a high water
content have lower energy densities (there are
no kJ in water) (e.g. fruits and vegetables)
19.
20. ENERGY DENSITY OF COMMON FOODS
Food Energy (kJ/g) Why?
pure fat e.g. oil 37 100% fat
butter, margarine 30 83% fat
chocolate 23
cheese 17 50% fat
bread 10 50% H2O
steak 9 > 50% H2O
soft drink 2 mainly H2O
celery 0.2 >90% H2O
21. ENERGY EXPENDITURE
Basal Metabolic Rate (BMR)
Min amount of energy required to maintain vital functions
60-70% of total energy exp.
dependent on
body size
body composition
Gender
Age
other factors
BMR lowest when resting
Increases steeply as energy is used by muscles (i.e. during
exercise)
22. ESTIMATING ENERGY REQUIREMENTS
Estimating BMR
Prediction equations used
Based on:
age
sex
height
Weight
Commonly used in Australia are the Schofield equations
although there are many others
23. SCHOFIELD EQUATIONS
Males 10-18 (0.074 x wt) + 2.754
18-30 (0.063 x wt) + 2.896
30-60 (0.048 x wt) + 3.653
Over 60 (0.049 x wt) + 2.459
Females 10-18 (0.056 x wt) + 2.898
18-30 (0.062 x wt) + 2.036
30-60 (0.034 x wt) + 3.538
Over 60 (0.038 x wt) + 2.755
Important – These are estimations only. There is considerable
variation between individuals & even within individuals over time
24. ENERGY EXPENDITURE
Calculating total energy expenditure
Need to take into account minimum amount required (BMR) and
multiply by a factor to take daily activities and exercise into
account
BMR estimated multiply by activity factor
Range of activity factors (resting very heavy activity)
Resting Very heavy
Activity factor continuum activity
1.2
6 - 12
TEE = BMR x av. activity factor across the 24-hr day
25. SCHOFIELD ACTIVITY FACTORS
Activity Level Males Females
Bed rest 1.2 1.2
Very sedentary 1.3 1.3
Sedentary/Maintenance 1.4 1.4
Light 1.5 1.5
Light/Moderate 1.7 1.6
Moderate 1.8 1.7
Heavy 2.1 1.8
Very heavy 2.3 2.0
29. INTEGRATING INFORMATION ON
NUTRITIONAL STATUS
Nutrition Assessment involves integrating
information from a number of different sources to
define the specific problem & also how it might be
addressed
30.
31. FOOD SUPPLY DATA
Provide information on:
Long-term trends in the availability of the major commodity groups
(grain, dairy, meat, F & V)
The types of nutritional problems that are likely in different
countries
e.g. where energy supply available is:
≥ 12000kJ/person/day obesity & heart disease are common
< 8000kJ/person/day under-nutrition is likely
The types of foods that supply energy
32. MORTALITY & MORBIDITY DATA
Provide information on:
diseases & conditions that are reported as causes of
death/hospital admissions
possibly on chronic conditions such as cancer &
diabetes
Reflect:
the major social & health problems of the community
And can be used as:
clues to the most likely causes of mortality &
morbidity
measures of the prevalence of specific nutrition
related conditions
33. MORTALITY & MORBIDITY DATA
Only provide information on:
Indirect measures of the kinds of nutritional
problems most likely to be encountered in a
population
Multi-factorial aetiology of conditions in
developed countries
Current burden of disease statistics available
from the AIHW
Disability adjusted life years (DALYs) are the years of life lost
due to premature mortality & disability & measure the number
of healthy years of life lost as a consequence of death or
newly diagnosed disease or injury in the population.
34. ANTHROPOMETRIC DATA
Weight & height are used in population studies as they:
provide an overall measure of nutritional status
are non-invasive
are quick to carry out
use minimal (& cheap) equipment
Provide information on:
the growth of children
the prevalence of obesity or underweight
35. DATA FOR CHILDREN
Infant birth weight
Provides information on:
maternal health & nutritional status
risk of infant mortality
Is influenced by:
maternal body size, infection, smoking, alcohol consumption, maternal
nutrition during pregnancy
Also
affects
Infant mortality data
% related to prevalence of low birth weight (populations with
high rates of low birth weight usually have high rates of infant
mortality) e.g. Indigenous Australians
36. INFANT FEEDING PRACTICES
Inappropriate infant feeding practices influences growth &
development esp. in the 1st 4 to 6 months
Decrease in breastfeeding at 3 months since 1945 (21% 1971,
above 50% since 1985)
Breastfeeding or correctly prepared infant formula infant
morbidity & mortality
37. MONITORING & SURVEILLANCE SYSTEM
A National Food & Nutrition Monitoring & Surveillance System
needs to collect data on:
Food supply & expenditure
Mortality & morbidity
Weight & height
Plus extra information on
Nutritional issues of particular
concern via specific nutrition
surveys (see week 3 lecture)
38. MONITORING & SURVEILLANCE SYSTEM DATA
NEEDS TO
be relevant to the major nutritional problems
encountered
be available to decision-makers within a
reasonable timeframe
be available on a regular basis
be collected by standard methods to enable
trends over time to be established
be presented appropriately
contain information relevant for changes to be
made
Hinweis der Redaktion
Because fats are the macronutrient providing the highest amount of energy per gram, foods that are high in fats have higher energy densities. Where as foods that are high in water content, like fruits, vegetables and milks, have low energy densities, because water contains no kilojoules.