Lecture 4 - Anthropometry and Body Composition

Advantages of anthropometry and body composition data

- many are easy to determine and obtain

- many are quick to determine and non-invasive

Anthropometry and body composition data is useful to

- estimate nutritional status

- evaluate growth

- determine response to treatment

- track changes over time

Main limitation of anthropometry and body composition data

- overestimation of height

- underestimation of weight

= overestimation of BMI

What do we compare anthropometric measurements to

- indicators

- reference data

- standards of growth and development (growth charts/curves)

Comparisons of anthropometry allows to see

Change (ex. Rate of growth)

Anthropometry is helpful to predict

Trends

Ex. Pattern of weight change

Anthropometry is helpful to estimate

Nutritional adequacy

Ex. Growth pattern

Crossing the ___nd percentile is considered failure to thrive

2nd

Growth stunting percentile

Length/stature-for-age below 3rd percentile on growth charts, but appropriate weight for ht

What may stunting/height reflect

Long-term malnutrition in infants, children, and teenagers

Wasting percentile

Wt-for-length/stature below 3rd percentile OR BMI-for-age below 5th percentile on growth charts

What may wasting reflect

Recent, short-term malnutrition or dehydration in infants, children, and teenagers

______ is a more sensitive measure of nutritional status than _____ in children

Weight

Height

Weight reflects

Recent nutritional intake

Weight provides gross estimation of

Muscle and fat stores

Limitation of UBW

Relies on memory

Height and length measurement requires a

Statiometer (measuring rod)

Stature

- standing height

- starting when toddler can stand straight (2-3 y.o.)

Standing height procedure

- remove shoes

- stand straight

- spine against measuring surface

- shoulders relaxed, arms at side

- heels together, feet flat

- heels, buttocks and shoulder blades touching measuring surface

- head and eyes looking forward "Frankfort horizontal plane"

- compress hair

Indirect measurements of height and length to be calculated if pt is

- bed/chair bound

- not able to stand or stand straight

Knee height procedure (RED)

- Bend both left knee and ankle at 90 degrees

- put fixed blade of a large, sliding caliper under heel

- put moveable blade of caliper over anterior surface of the thigh, proximal to patella

- measure distance with caliper shaft parallel to tibia and fibula

What position gives more accuracy than sitting for knee height measurement

Supine position (lying face up)

knee height calculations white male (18-60 yrs)

male:

Ht(cm) = 71.85 + (1.88 x knee ht(cm))

Knee height calculations white female (18-60 yrs)

female:

Ht(cm) = 70.25 + (1.87 x knee ht(cm)) - (0.06 x age)

recumbent length

Measurement of length while the child is lying down. Recumbent length is used to measure toddlers <24 months of age.

- measured with pt lying flat on bed

When is recumbent length not accurate

If pt has musculoskeletal-skeletal deformities

Arm span procedure

- stretch arms out from body at 90 degrees

- measure distance from tip of middle finger on right hand to tip of middle finger on left hand

Arm span reflects _________ _________ in adults

Maximal height

Who might arm span not be accurate for

African Americans and asians

Body weight is determined using

- standing scale

- chair scale

- bed scale

- pediatric scale (wt lying)

Types of scales

Electronic

Balance beam

What type of scale is used for paediatric

Pan type

What scales are not recommended

Spring-type bathroom scales

Procedure for standing scale

- make sure scale is calibrated

- zero scale

- remove shoes and heavy clothing

- Stand still in center of scale w/o assistance

- account for amputations

Body weight can be calculated using which measurements

- knee ht

- mid upper arm circumference (MAC)

- calf circumference

- sub scapular skinfold thickness (SSF)

Wt (kg) in males using KH, MAC, CC, and SSF

= (MAC X 1.73) = (CC X 0.98) + (SSF X 0.37) + (KH X 1.16) - 81.69

When would weight not be able to be obtained, therefore using KH, MAC, CC, and SSF

ICU patient attached to life support equipment

Waist circumference correlates with

Visceral fat stores

Waist circumference helps to predict

Risk of diseases associated with obesity

Waist circumference may not be accurate if

BMI > 35

Ht < 5 feet (1.52 m)

Android obesity

- apple shaped

- fat carried abdominally

- more vulnerable to disease than those who are gynoid or pear shaped

waist circumference procedure

- stand straight, abdomen relax, feet together, arms at side

- measure distance around smallest area of body, above umbilicus and below rib cage when pt breathes out

Asian and Chinese ethnic specific values for waist circumference: high risk for CVD (RED)

Men: >90

Women: > 80

Hip circumference procedure

- stand straight, abdomen relax, feet together

- measure distance around largest area of hips with tape measure (point of greatest circumference)

Mid upper arm (MAC) circumference reflects

Skeletal muscle + bone + subcutaneous fat

Mid upper arm (MAC) circumference procedure

- stand or sit and ensure easy access to right arm and shoulder

- bend arm to 90C

- measure distance between acromion process of scapula and tip of elbow (olecranon)

- determine and mark the mid-upper arm point

- use tape measure to determine arm circumference at that halfway point (tape perpendicular to long axis of arm)

What is the wrist circumference useful for (RED)

To determine the bone frame size

Wrist circumference procedure

- measure around smallest area of wrist, distal to styloid process (of the ulna and radius) and towards the fingers

Calf procedure

- stand or sit

- heels on floor, 20 cm apart

- measure around largest part of calf at +- 0.1cm, tape measure perpendicular to long axis of leg

- if sitting, bend knee at 90 degrees

Elbow breadth procedure

- flex elbow to 90 degrees

- point sliding caliper blades upward

- measure distance between epicondyles of humerus (widest part of elbow)

- compare to standards

Indexes

Combination of measurements

Waist-to-hip ratio evaluates

The distribution of fat (subcutaneous and intra abdominal) and muscle tissue

Waist to hip ratio =

waist circumference / hip circumference

Hip Circumference Measurement

- around the max circumference of the buttocks

- for women, usually at groin level

- for men, usually about 2-4 inches below the naval

%UBW =

CBW/UBW X 100

%UBW: mild malnutrition

85-95%

%UBW moderate malnutrition (RED)

75-84%

%UBW severe malnutrition

< 74% UBW

What %UBW is necessary for survival

48-55%

% weight change =

UBW-CBW/UBW X 100

Significant weight loss in 7 days

1-2%

Severe wt loss in 7 days

>2%

Significant weight loss in 1 month

5%

Severe wt loss in 1 month

> 5%

Significant wt loss in 3 months

7.5%

Severe wt loss in 3 months

> 7.5%

Significant weight loss in 6 months

10%

Severe weight loss in 6 months

> 10%

Significant wt loss in unlimited time

10-20%

Severe weight loss in unlimited time

>20%

1 kg = ? lbs

2.2 lbs

1 inch = ? cm

2.54 cm

1 foot = ____ inches

12 inches

Underweight BMI and risk of comorbidities

<18.5

- low (but risk of other clinical problems is increased)

Normal weight BMI and risk of comorbidities

18.5-25

- average

Overweight BMI and risk of comorbidities

25-29.9

- increased

Class 1 Obesity BMI and risk of comorbidities

30-34.9

- moderate risk

Class 2 Obesity BMI and risk of comorbidities

35-39.9

- severe risk

Class 3 Obesity BMI and risk of comorbidities

> 40

- very severe risk

Comoribidity

the presence of more than one disorder

%IBW =

CBW/IBW x 100

%IBW in adults: class 3 obesity

> 200%

%IBW in adults: obese

130-199%

%IBW in adults: overweight

110-129%

%IBW in adults: mild malnutrition

80-90%

%IBW in adults: moderate malnutrition

70-79%

%IBW in adults: severe malnutrition

< 69%

Mild underweight BMI

17-18.4

Moderate underweight BMI

16-16.9

Severe underweight BMI

< 16

Waist to hip ratio: men (increased risk of morbidity and mortality) RED

> 1.0 in men

Waist to hip ratio: women (increased risk of morbidity and mortality) RED

> 0.8

Waist circumference in Europids: men (increased risk chronic disease)

> 94cm

Waist circumference in europids: women (increased risk chronic disease)

> 80cm

IBW normal range in percentile

Between 5th and 95th percentile

3 ways of determining IBW

- quick way

- hamwai

- BMI method

Quick way of determining IBW (RED)

Ht in cm-105 = IBW in KG (lower end)

Ht in cm-100 = IBW in KG (highest end)

Calculation IBW using BMI method

Desirable BMI = IBW/ht in m2

Desirable BMI x ht2 = IBW (kg)

Goal BMI = 18.5+24.9 = 43.4/2

Goal BMI = 21.7kg/m2

Ht 1.6m2 = 2.56m

21.7 x 2.56 = 55.6 kg

Body composition is the evaluation of

Body content (muscle, fat, water, bone, etc.)

Body composition is determined using

- circumference and areas

- skinfold thickness

- bioelectrical impedance analysis (BIA)

- dual energy x-ray absorption entry (DEXA)

- air displacement plethysmography (bod pod)