Assessment of Nutritional Status - Anthropometry Flashcards
Describe ‘anthropometry’.
The study of body measurements
including:
- taking, recording and analysing body measurements
The breakdown of your body’s make up:
- lean mass
- fat mass
- bone
- water %
Why is anthropometry important?
- Understand fat distribution
- Identify and understand wasting
- Estimate energy requirements of individuals
- Predict the effects of weight loss/gain on body tissues
List some factors that affect body composition
- Gender
- genetics
- diet
- Age
- level of physical activity
- health status
describe the two compartmental model
body is made up of
- lean body mass LBM (or fat free mass FFM)
- fat mass
describe lean body mass
the weight of all components of the body except fat (e.g., bone, muscle, water).
describe fat mass.
the fat compartment in the body
20% water and 80% adipose tissue
What are the body fat ranges for a female aged 20-39?
underfat = 0-21% healthy = 21-33% overfat = 33- 39% obese = 39%+
what are the body fat ranges for a male aged 20-39%
underfat = 0-8% healthy = 8-19% overfat = 19-25% obese = 25%+
List the main methods of measuring body composition
Anthropometry bio-electrical impedance densitometry total body water total body potassium MRI DEXA
Why can total potassium content be used to measure body composition?
Fat free mass has a constant proportion of potassium.
What does densitometry measure and how?
Fat mass and fat free mass
Requires measure of total body mass as whilst the weight of FM is relatively constant, the mass of LBM varies according to composition.
What does densitometry measure and how?
Fat mass and fat free mass
Requires measure of total body mass as whilst the weight of FM is relatively constant, the mass of LBM varies according to composition.
Describe ‘BMI’
Body mass index
Weight (Kg)/Height^2 (m)
predicts fatness and health status
aims to correct individuals weight, in relation to their height
Describe the BMI categories for adults
underweight - less than 18.5 healthy/normal - 18.5-24.9 overweight - 25-29.9 obese class 1 - 30-34.9 obese class 2 - 35-39.9 obese class 3 - 40+
Why is BMI so widely used?
crude indicator of weight judgement (WHO)
BMI highly correlates to fat mass for most individuals e.g., not athletes
good predictor for body fat %
Describe the relationship between BMI and mortality rate
‘U-shaped curve’
underweight - high risk lower healthy range - low risk healthy - minimal risk higher healthy range - low risk overweight - moderate risk obese - high risk upper limit of obese - extremely high risk
How is ‘waist circumference’ measured?
tape measure on bare skin
measure of girth at the midpoint between the lower rib and iliac crest
What are some pros and cons of waist circumference?
Pros
- quick, inexpensive and easy
- effective at assessing risk in ppl with BMI between 25-34.9
Cons
- cultural insensitivity
- room for error = low reliability
What body components does waist circumference measure?
both abdominal subcutaneous and visceral adipose tissue
Why is Waist Circumference an effect marker of disease?
high WC = high central adiposity i.e., fat around central organs
excess amount of fat around abdomen that is disproportionate to total body fat is a marker of diseases associated with obesity, and metabolic syndrome
even with healthy BMI, high WC indicates disease risk
What is the desirable WC for males and females?
Males - less than 94cm
females - less than 88cm
Describe ‘Waist to hip circumference ratio’§
A measure used to describe the distribution of subcutaneous and intra-abdominal adipose tissue