NUTRITION ASSESSMENT
I. Importance
A. Identify problems so corrective action can be taken to improve nutritional status.
B. Determine if a person is well nourished enough to survive surgery or other treatments.
II. Components
A. Historical information
B. Anthropometric data
C. Biochemical (laboratory) data
D. Physical exam
III. Historical information
A. Health history - may impact nutritional status
1. Previous or present alcoholism
2. Previous or present disease conditions
a. diabetes
b. cancer
c. renal disease
d. thyroid disorders
3. Previous or present eating disorders
4. Family history of obesity
5. Previous surgeries
6. Mental impairment
7. Weight changes
8. Dentition
9. Exercise habits
B. Socioeconomic history - personal, environmental, financial influences onfood intake
1. Eating alone
2. Lack of money
3. Inadequate food preparation facilities
4. Poor education (eg, reading)
5. No transportation
6. Family problems that may result in low self esteem (eg. Excessive value of
appearance in the family of a patient with eating disorders)
7. Drug history
a. antidepressants - increase or decrease appetite
b. diuretics - may waste potassium
c. antacids (baking soda may contribute to sodium intake)
d. vitamin/mineral supplements
C. Diet history - provides a record of a person's food intake so that nutrient intake can be
estimated and provides information so dietitian can predict how well the client
will accept diet changes (in general, the fewest changes from usual diet, the better
the compliance)
1. Information obtained
a. types of foods consumed
b. quantity of foods consumed (food models help client estimate)
c. how foods are prepared
d. dining out frequency
e. beverage consumption (including alcohol)
f. supplement consumption
2. Accuracy of data collected
a. NON-JUDGMENTAL - some people are very sensitive about
eating habits and weight
b. technique of asking questions (avoid leading questions)
3. Tools
a. 24-hour recall - record everything eaten in the last 24 hours
1. memory problem
2. may not be typical day
3. can do computerized diet analysis
b. Usual intake (probably used most for diet histories)
1. good for people who have regular eating habits
2. sometimes used in combination with 24 hour recall
3. can give overall impression of diet, snacking patterns,
consumption of sweets, etc.
c. Food frequency checklist - how often the person eats food on
a list (several times a day, daily, weekly, monthly)
1. not extremely precise
2. list of foods must be extensive
3. can give general impression of eating habits
4. sometimes used in combination with 24 hour recall
d. Food diary - prospective record of foods eaten over a period
of time (usually 3 days or 7 days). Average daily intake
is calculated for each nutrient.
1. 3 days is pretty accurate if you have 2 weekdays and
1 weekend day
2. Can get info on time, place, with whom, and hunger
and emotional state
3. Just keeping a record may change a person's food
intake and therefore affect accuracy
4. Can compare overall food habits to guidelines (pyramid) for general
impression of dietary adequacy
5. If computerized analysis is done, can compare individual nutrients to RDAs
a. RDAs are designed for healthy people
b. computer analysis implies more accuracy than reality
a. substitutions
b. incomplete data on some nutrients
c. nutrient levels in food composition tables are averages
d. accuracy of portion sizes
6. Caveats
a. Adequate intake doesn't guarantee adequate nutritional status (may not
absorb)
b. Inadequate intake doesn't always indicate deficiency
7. Bottom line - diet history gives the dietitian a rough estimate of food intake so that
problems or potential problems can be identified. Ultimate nutritional status can
only be determined when diet history information is considered along with other
components of nutritional assessment
II. Anthropometrics
A. In general
1. Gives information on body composition
a. initial measurement provides baseline to monitor changes in
nutritional status
b. monitors progress of growth in pregnant women and
infants and growing children
c. detects undernutrition and obesity
2. Measures are compared to standards from population studies
a. problem - population data may not apply to a
particular individual
b. use a variety of anthropometric measures for most
accurate anthropometric assessment
B. Anthropometric measures
1. Height and weight - most common
a. Height
1. special equipment needed for kids under age 3
- lie kid down on special table with head at head board,
straighten out legs and take length measurement at heel
2. adult - use stadiometer
a. without shoes, heels together
b. inflexible object on top of head
c. use a stool if you are shorter than person
d. can be estimated by 2X measurement from sternal notch
to fingertips
e. can be estimated from knee height
b. Weight - beam balance, electronic most accurate
1. infants - weigh in balance scale that allows kid
to lie (naked without diapers)
2. adults
a. for repeated measures, same scale, same time of day,
after voiding, in same weight clothing, without
shoes, morning before breakfast is probably best
3. Scales have upper limits - can add weights to
beam balance to increase limit
4. Remember that a lot of people are sensitive about their weight,
so don't show judgment
c. Interpretation
1. infants to age 20 use CDC growth charts
a. get percentile for height and weight for age
1. 50th percentile is average
2. height and weight should be within 2
percentile ranges
3. there are charts for weight for height BMI, and
head circumference
b. Low percentiles may not de due to
undernutrition or poor health, may be due to
genetics (are parents short?, is weight for height
OK?)
c. Types of malnutrition indicated
1. acute (recent poor intake)
a. height normal, low weight
b. weight is affected by malnutrition
before height (lose body stores
first, then linear growth slows)
2. acute on chronic - continuing long term
poor intake
a. low weight and height percentiles
b. weight for height low
c. length of time undernourished has
affected linear growth as well
as body stores
3. past chronic
a. low height, OK weight
b. weight for height may be OK
c. past long term undernutrition has
affected linear growth,but body
stores have been repleted (it
takes longer for linear growth
to catch up than body stores)
Note: if growth plates on bones
have closed, catch up growth
will not occur
d. Look for trends in growth curve,sudden slows in
growth are a concern
e. Obese - try to have weight gain slow and let height "catch
up" to weight
2. Adults
a. Height-weight tables (Metropolitan,1983)
1. based on mortality rates of insured
population (mostly white)
a. Divided into frame size categories
1. ht(cm)/wrist circ. (cm) = r =
small
medium
large
men
>10.4
9.6 - 10.4
<9.6
women
>11.0
10.1 - 11.0
<10.1
2. elbow breadth
b. other countries use other
standards (FAO/WHO),
Indonesia has own h-w tables
b. Calculation of ideal body weight (IBW)
1. Traditional
a. women
1. 100 # for 1st 60 in
2. add 5 # for each in, over 60
3. large frame, add 10%; small
frame,subtract 10%
4. eg
b. men
1. 106# for 1st 60 in.
2. add 5 # for each in. over 60
3. add or subtract 10%
depending on frame size
2. Newer (closer to Ins. Tables)
a. Women: 119+3# for every
in. over 60 in. (frame size adj)
b. Men 135+3# for every in.
over 63 in. (frame size adj)
c.
d.
e.
f.
g.
Can add 10% for those over 50
Subtract 5-10% for paraplegic; 10-15% for quadraplegic
Range of weights may be best
Problem - can be overweight without being over fat.
What to use in calculations
1. Adjusted body weight (for obese)
a. useful for equations to calculate
energy and protein needs
b. .25(Current BW - IBW) + IBW
2. Actual body weight for those within
normal weight range
3. Desirable body weight if underweight
i. Clinical interpretation
% IBW
>200
>120 or 130
110 - 120
80 - 90
% UBW
85-95
Nutritional status
morbidly obese
obese
overweight
mildly undernourished
70-79
<70
75-84
<75
mod. undernourished
severely undernourished
2. BMI (Body Mass Index)
a. weight (kg)/ht2 (m)
b. 20 - 25 - least risk of death
c. BMI > 25 is associated with obesity and greater risk of
death
d. Grades of obesity according to BMI
I 25 - 29.9
II 30 - 40
III 40+
3. Circumferences
a. Head - used in children, estimates brain growth
b. measure at largest part of head
c. compare value to NCHS chart
4. Waist-to-hip ratio
a. waist - measure at umbilicus (controversial)
b. hip - measure at largest circumference
c. divide waist by hip
d. interpretation
1. women > .8, apple (android)
2. men > 1.0, apple (android)
e. android body fat distribution is associated with a greater risk for some chronic
diseases compared to gynoid or peripheral distribution
5. Body composition
a. percent body fat
1. methods
a. multiple site skinfold
b. bioelectrical impedance
c. dual energy x-ray absorptiometry
d. body fat wand
e. estimation by circumferences
f. bod pod - air displacement
2. interpretation
a. appropriate levels not well defined – need to collect a lot
more data over many years to correlate % body fat
to longevity
b. average
< 30 y/o men
> 30 y/o men
< 30 y/o women
> 30 y/o women
12 - 15%
18 - 27%
22 - 29%
25 - 34%
In general, over 25% in men and 33% in
women is considered overfat; under 3% in
men and 12% in women is underfat
b. Somatic protein measures
1. hand grip strength - new, not widely used - strength
is correlated with malnutrition
2. Mid-arm muscle circumference (MAMC) circumference of biceps muscle declines with
malnutrition as protein reserves are depleted
3. measurement
a. Measure triceps skinfold
b. Measure midarm circumference
c. calculation MAMC = Midarm circumference (cm)
- (.314 triceps fatfold (mm))
III. Biochemical indices - tells what's going on internally
A. useful in assessing protein, vitamin, mineral status
B. Sensitivity - ability of a test to indicate abnormality when abnormality exists
1. some tests will not catch a problem in early stages, other, more sensitive tests
will
2. eg., hb/hct are less sensitive than ferritin for determining iron deficiency, so
hb/hct does not diagnose until anemia is advanced
C. Specificity - ability of a test to indicate normal when no abnormality is present
1. Some tests of nutritional status can be abnormal for reasons other than
nutritional problems
2. eg., Albumin could be low due to liver disease, not deficient protein intake
D. blood
1. serum (blood minus cells and clot forming materials)
2. plasma (blood minus cells)
3. tests
a. SMA - simultaneous multiple analysis
b. CBC - complete blood count
4. dehydration concentrated blood and can falsely elevate values
5. hemodilution can falsely lower values
6. deficiency can be in progress before lab values reflect because stores may be
released into blood
7. metabolites with short half-lives reflect recent nutritional status, metabolites
with long half lives reflect long term status
a. albumin - half life 23 days
b. pre-albumin - half life 3 days (detects quick changes in nutritional
status)
D. Urine
1. specific gravity - hydration status
2. nitrogen balance
3. creatinine excretion
E. Common tests related to nutritional state
1. Protein nutrition
a. albumin
1. low values indicate prolonged protein malnutrition (long halflife and albumin can shift out of the cells into blood to slow
decline)
2. slow to respond to nutrition therapy so not good
indicator of improvement of status
3. disease states may affect albumin levels
b. prealbumin – shorter half life – tells recent changes in protein status
c. transferrin (protein that transports iron)
1. short half life, small body pool
2. not accurate indicator of protein status if iron status is poor
d. retinol binding protein (carries vitamin A) and prealbumin are sensitive
indicators
e. total lymphocyte count (TLC) - protein malnutrition depresses the
immune system
1. run with CBC
2. Calculation - WBC (mm3) X % lymph
f. Antigen skin testing (delayed hypersensitivity (DH)- antigens to which
most people are immune are injected just under the skin. After 48
hours site is checked for induration (hard raised area), and is scored
from 0-2. If little or no induration - impaired immune status.(Other
factors can affect this test, so it should not be the sole biochemical
test for malnutrition)
g. Nitrogen balance - assesses rate of depletion or repletion
1. Nitrogen input = protein intake (g)/6.25
2. Nitrogen output = amount of nitrogen in a 24 hour urine
collection
(UUN) plus 4 (skin, fecal, etc losses)
3. nitrogen bal = input - output
h. Urinary creatinine excretion
1. creatinine is a breakdown product of phosphocreatine an energy
source in skeletal muscle
2. amount excreted in urine is proportional to skeletal muscle mass
3. as muscles atrophy, excretion decreases
4. protein intake, menstrual cycle can affect
2. Cholesterol and lipoproteins
3. Hemoglobin/hematocrit - iron, hydration status
IV. Physical exam - physical signs are last to appear in the progression of malnutrition
A. Steps of malnutrition
1. Lack in diet (historical information)
2. Stores decline (anthropometric and biochem)
3. Body functions abnormally (biochemical)
4. Physical signs appear
Note: Some physical signs have low specificity, eg, dry, scaly skin
B. Some physical signs associated with malnutrition
Sign
Dull, thin, dry
hair that is easy
to pluck
Possible nutrient deficiency
Scaly skin around
nostrils, cheilosis
riboflavin
Swollen face
Kwashiorkor
Pallor
Iron
Dullness, dryness
of cornea
Bitot's spots
Vitamin A
Fissuring of eye corners
Riboflavin, B-6
Magenta tongue
Atrophy or hypertrophy
of taste buds
Riboflavin
Mottled tooth enamel
Protein
Folic acid, niacin
Fluoride excess
Spongy, bleeding
receeding gums
Vitamin C
Thyroid enlarged
Iodine
V. Estimation of nutrient needs
A. energy maintenance needs- Harris-Benedict equation (BEE) times activity and stress
factors most commonly used
1. BEE
a. (women) = 665 + (9.6 X wt (kg)) + (1.7 X ht(cm))
- (4.7 X age (years))
b. (men) = 66 + (13.7 X wt (kg)) + (5 X ht (cm))
- (6.8 X age (years))
Note: use adjusted BW if person is >125% IBW
2. multiply by each factor that applies
a. Activity
1. very light/sedentary 1.2 -1.3
2. Light (no plnned activity, mostly officework) 1.5-1.6
3. Moderate (walking, stairclimbing during day) 1.6-1.7
4. Heavy (planned vigorous activities) 1.9-2.1
b. Stress
1. uncomplicated surgery 1.1 - 1.5
2. complicated surgery or fractures 1.2 - 1.4
3. Major burn 1.5 - 2.0
c. Fever 1.3 for each degree C above nrml
f. Anabolism
1. 0.5 if pt experienced moderate weight loss
2. 1.1 - 1.5 if pt experienced severe weight loss
3. example
4. Alternative to Harris Benedict times factors: kcal X kg body wt
Overweight
Normal
Underweight
Sedentary
Moderate
Active
20-25
30
30
30
25
40
35
40
45-50
Athlete (90 min/d): 45-50 kcal/kg
Hospitalized patients in stress: 40 - 45 kcal/kg
Most other hospitalized patients: 30-35 kcal/kg
5. Equations provide a place to start - adjustment may be made for individual
variation
B. Protein
1. Nitrogen balance - Nitrogen in - Nitrogen out
2. Equations
Person
Protein needs per kg body wt
Healthy
.8 - 1
Fever, fracture, infection
1.5 - 2.0
Protein depleted
1.5 - 2.0
Extensive burns
1.5 - 3.0
Endurance athlete
1.2 – 1.4
Strength
1.6-1.7
VI. Special Considerations
A. Pregnancy
1. blood volume expands, hemodilution (H/H low)
2. cholesterol increases
B. Amputations - subtract according to % of body missing
C. Deformed - may be impossible to measure accurately
D. Elderly
1. naturally lose lean body mass and increase in proportion of fat as
age, then very old tend to lose fat stores
2. Probably good to have some reserves
3. H/H tend to be low - may be a normal process of aging - less lean tissue, don't
need as much hemoglobin (less tissue to oxygenate)
4. More prone to malnutrition
a. lack of appetite
b. presence of chronic diseases
c. GI function declines
d. many drugs
e. mental problems
Overall Macronutrient:
Carbs
General 60-65% kcal
Endurance 65-70% kcal or 7-10 g/kg
Protein
General .8g/kg or 12-15% kcal
Endurance 1.2-1.4 g/kg
Strength 1.6-1.7
Fat
Max of 30%