Body Composition and Obesity Part 1 Flashcards
Most common measure of obesity?
BMI = kg/ m squared
BMI of a normal weight
18.5 - 24.9
What is body composition divided into (2)
Fat and fat free-mass
What is fat free mass
Everything that is not fat
What does the 3 compartment model consist of in imaging?
Fat mass, bone mass, lean mass (fat and bone free)
3 ways to get more detailed description of body composition
CT, MRI and dexa
What does the 4C model consist of?
Fat, skeletal muscle, organs and remaining soft tissues, minerals (all fat free mass)
Eight techniques of assessing body fat ( ABCCDTMs)
- Age, height and weight tables and weight prediction equations
- Cadaver analysis
- Densitometry
- Bioelectric impedance analysis (bia)
- Skinfold measurements
- Computed tomography. (CT scan)
- Magnetic resonance imaging (MRI)
- Total body density (dxa)
Most accurate body composition measurement
Cadaveric analysis, however it is very impractical. it takes direct measure of body tissues
Densotimotery
Density is proportional to our fat free mass. We are put into water or air compartments with known volume
BIA ( bioelectrical impedance analysis )
Electrical currents through the body works by how fast current travels, slower means more fat. Type we used in lab. Requires equations
What type of fat does skin folds measure
Subcutaneous
Sites of skinfold measures
Biceps, triceps, subscapular and supra-iliac, thigh, calf, andomen
CT scans (computed tomography )
( 4C model) gives off radiation. Expensive and time consuming. High density tissues (bone ) show up white and darker grey for low density (fat)
MRI (Magnetic Resonance Imaging)
4C model. Magnetic fields instead of radiation and is loud. Reverse shading than CT scan and is expensive and time consuming
DXA (dual energy X-ray absorptiometry)
3c model. Low radiation and costs less than MRI and CT. Lean mass and abdominal fat not muscle mass and visceral fat. Originally for bone density. Whole body scan but can also do regional analysis.
Six factors influencing body composition analysis
- Perform in morning
- Before breakfast
- Ensure hydration
- Same time of day
- Same technician
- Same equipment
Anthropometry
Waist and hip circumference
What is Gynoid
Fat on hips and butt (not associated with health risk factors)
What is android
Fat at waist. Enhanced risk for high BP, CVD, diabetes, and abnormal blood lipids
What is android
Fat at waist. Enhanced risk for high BP, CVD, diabetes, and abnormal blood lipids
How does fat determine health
Not only amount, but also location
Visceral vs. Subcutaneous fat
Visceral is more “bad for you” because it’s deeper in tissue. it affects organs
