Antropometry Flashcards
What is anthropometry?
The measurement of human body composition
Why is body composition measured?
- Establish physical growth, maturation and development
- Monitoring health status
- Screening to determine ‘at risk’ individuals –> over or undernutrition
- Assess response to interventions –> medications
- Medication response
- Sports performance
What are some indirect methods of estimation?
Portable methods
- Skinfold measurements
- BIA
- Ultrasound
Laboratory methods
- Hydrostatic/ underwater weight –> body density
- Isotope dilution –> total body water estimate
What amount of weight loss can decrease risks?
5-10% of body weight
- even if the person still has an obese BMI
What is the Frankfurt plane?
Measurement of stature when measuring height
How is the rate of change measured?
Weight loss
Actual weight- usual weight / days between measurement
What is android obesity?
Adipose tissue stored around the abdominal area
Cause an increase in W:H
What is gynoid obesity?
Adipose tissue stored mainly around hips and thighs
Can decrease W:H
What do skinfold measurements do?
Measures double the thickness of subcutaneous fat and 2 layers of skin
8 different sites where skinfold measurement can be done
Different equations for different types of people
Cheap, fast, portable
Measures variation in fat distribution
A good tool for comparison to track changes in a individual
What does BIA do/ show?
Types?
Assess how the body conducts electrical current
- measures impendence (resistance of tissue to flow_
- fat free mass - good conductor
- fat mass - poor conductor (high impedance, blocks current)
Estimates FM, FFM, TBW, BF%, BMI
Easy and quick to use
Equations take into account gender, race and age
Hydration levels to be consistent for every measurement
Single frequency
- Hand to foot
- Hand to hand
- Foot to foot
Dual or multi-frequency BIA
- Estimates body composition at arms, legs, and trunk as well as total body
Discuss hydrostatic weighing
Estimates body composition from body density
Density = mass/volume
Mass is measured on a regular scare
Volume based of Archimede’s Principle
Subject must exhale all water as the head is lowered into the water, may be some air remaining in lungs or GI tract
What is Air Displacement Plethysmography?
BodPod
- Air displaced = body volume
- High validity when compared to hydrostatic weighing
- Takes 3-5 minutes
- Must wear tight ‘swimwear’
- Expensive
- Can calculate TDEE for the individual
PeaPod
- For babies
- Take approx. 7 minutes
- Safe, non-invasive evaluation of babies body composition
What is DEXA?
Dual energy x-ray absorptiometry
- Measures difference in absorption of 2 different low x-ray energies to estimate bone mass and mineral density
- Low error
- Ability to estimate composition in defined regions
- Exposure to radiation
- Expensive
- Less accurate in obese and tall - measures in certain segments
- Test risk of osteoporosis
What is the Multi-compartment model?
Involves 4 compartments
- BMC by DEXA
- TBW by isotope dilution
- Body volume by Air Displacement Plethysmography
- Body weight (kg)
Calculates fat
What is an Isotope Dilution?
Determines TBW by introducing a marker fluid that moves freely through the body, but is not metabolised.
Body fluid sampled pre-dose and 4 hour post dose
Conversion formula applied to TBW
FM = BW - (TBW/0.732)
