Lecture 6 - Body Composition Flashcards
1
Q
What are three reasons to assess body composition?
A
- Classify disease risk
- Sport performance
- Weight management
2
Q
What are 2 methods of measuring body composition CSEP uses?
A
- BMI
2. Waist circumference
3
Q
What are 4 methods to measure % body fat?
A
- Densitometry
- Dual-Energy X-Ray Absorptiometry (DEXA)
- Bioelectrical impedance
- Skinfold measurements
4
Q
BMI does not account for _______ of fat mass vs FFM
A
composition
5
Q
r = 0.70 in correlation with ________ _______.
A
hydrostatic weighing
6
Q
BMI < 18.5
A
Underweight; increased risk
7
Q
BMI 18.5-24.9
A
Normal weight; least risk
8
Q
BMI 25-29.9
A
Overweight; increased risk
9
Q
BMI 30-34.9
A
Obese class I; high risk
10
Q
BMI 35-39.9
A
Obese class II; very high risk
11
Q
BMI >40
A
Obese class II; extremely high risk
12
Q
______ _______ is an indirect assessment of abdominal adiposity.
A
waist circumference
13
Q
WC for men > or equal to 90
A
high risk
14
Q
WC for men > or equal to 100
A
very high risk
15
Q
WC for men > or equal to 110
A
extremely high risk
16
Q
WC for men > or equal to 125
A
extremely high risk
17
Q
WC for women > or equal to 80
A
high risk
18
Q
WC for women > or equal to 90
A
very high risk
19
Q
WC for women > or equal to 105
A
extremely high risk
20
Q
WC for women > or equal to 115
A
extremely high risk
21
Q
WC for women > or equal to 125
A
extremely high risk
22
Q
Resistance trained clients who have a BMI in the overweight category but a WC below the cutoffs are (likely/unlikely) to be at increased health risk.
A
unlikely
23
Q
___________ = measurement of the size and proportion of the human body
A
anthropometry
24
Q
What is the healthy range for men?
A
teens
25
What is the obese rage for men?
> 22-25%
26
What is the healthy range for women?
twenties
27
What is the obese range for women?
> 35-38%
28
_________ estimates body density by determining the ratio of body mass to body volume.
densitometry
29
What is the equation for body density?
BD = BM/BV
30
What are the two methods of densitometry?
1. Hydrostatic weighing (hydrodensitometry)
| 2. Air displacement plethysmography (bod pod)
31
________ _______ is the criterion measure used for development of %BF prediction equations and validation of field measurements.
hydrostatic weighing
32
A leaner person is going to have a (higher/lower) underwater weight compared to a person weighting the same but with a different body comp.
higher
33
What is the equation for BV for hydrostatic weighing?
[(dry wt - underwater wt)/(density of water)] - (RV + 100mL)
34
What is the equation for BD for hydrostatic weighing?
dry weight/BV
35
____-_______ model is the foundation for many techniques to measure % body fat.
two component
36
Body mass = ?
fat mass (FM) + fat-free mass (FFM)
37
What is the density of FM?
0.901 g/cc
38
What is the density of FFM?
1.100 g/cc
39
Individuals differ from the reference body only in the amount of ___, and the proportional contribution of FFM components are constant
fat
40
Water = __%
73.8
41
Minerals = ___%
6.8
42
Protein = ___%
19.4
43
FFM ______ can vary substantially according to age, gender, physical activity level, ethnicity, relative proportion of water and mineral, and level of fatness.
density
44
When do 2C models work well when?
If underlying assumptions about FFM are met.
45
_________ models improve estimation of %BF by replacing the 'reference body' with a population specific body that takes into account age, gender, ethnicity and level of physical activity.
multicomponent
46
Air displacement _______ compares column and ______ of front chamber with the reference chamber to determine the volume of the individual.
plethysmography; pressure
47
Dual Energy X-Ray absorptiometry uses X-rays and a ___ _____ model of assessment.
3-component
48
Total body weight = ?
Bone mineral mass + bone free lean tissue + fat mass
49
Attentuation of X-rays is dependent on what 3 things
1. Thickness
2. Density
3. Composition of tissues
50
What is the reliability measure of DEXA?
r > 0.95
51
______ _______ measures resistance to electric current to estimate %BF.
bioelectrical impedance
52
Water reduces resistance and current moves easily in a (lean/fatty) tissue.
lean!
53
Dehydration or adipose tissue _____ current = fatter tissue.
slows
54
________ level determines resistance of tissues to flow or electrical current.
hydration
55
How variable is BIA?
3-8%! (high)
56
Skinfold measurements (SKF) correlated with body density for hydrostatic weighing ( r = ____).
0.76
57
SKF ________ measure thickness of subcutaneous adipose tissue.
indirectly
58
What are 4 assumptions of SKF measurements?
1. SKF is a good measure of subcutaneous fat
2. Fat distribution (subcutaneous vs. internal) is similar for all individuals within each gender
3. There is a relationship between sum of SKF and body density
4. The sum of several SKFs can be used to estimate total body fat
59
Estimated that ____ of body fat is subcutaneous.
1/3
60
What is a major source of error in test administration of the SKF procedure?
Landmark sites
61
What 6 things can FFM density vary with?
1. Age
2. Gender
3. Physical activity level
4. Ethnicity
5. Relative proportion of water and mineral
6. Level of fatness
62
________ measurements are correlated with body density from hydrostatic weighing (r = 0.76)
SKF
63
What are 3 key limitations to SKF measures?
1. Client sensitivity to having SKF measured
2. Substantial intra and inter-tester variability in SKF thickness
3. Time required for training, practice and accurate administration
64
For multicomponent models, the reference body used has a population specific body that takes into account what 4 things?
1. Age
2. Gender
3. Ethnicity
4. Level of physical activity
65
What is the reliability of the bod pod?
r = 0.9 - 0.96
66
How reliable is the DEXA?
> 0.95
67
Muscle cell = ____% water, fat cell = __ - __ % water
75; 5-13
68
What are 4 pre test guidelines for BIA?
1. No eating or drinking within 4 hours of test
2. No exercise within 12 hours
3. No alcohol within 48 hours
4. Urinate within 30 minutes of test
69
There is a strong correlation between ___ site SKF and ___.
12; MRI
70
Leaner individuals have a (higher/lower) proportion of internal fat.
HIGHER
71
What are 4 pros of SKF?
1. Relatively inexpensive
2. Easily administered by trained individuals
3. Can esteem the % BF
4. Reliable (r=0.9) with experienced testers
72
What are 3 cons of SKF?
1. Requires practice
2. Limited population (overeat, fascia etc.)
3. Variability in equations
73
What are 3 pros of BIA?
1. Fairly inexpensive
2. Easily administered and minimal training required
3. Quick - provides results instantly
74
What are 3 cons of BIA?
1. Variable
2. Pre-test guidelines
3. Electrical pathway (anklet ankle, ankle to hand)?
75
What are 5 pros of DEXA?
1. Gaining recognition as a criterion measure
2. Safe - low radiation
3. Quick (20 mins)
4. Requires minimal client cooperation
5. Estimates other components not obtained bu densitometry and provides regional and segmental composition
76
What are 4 cons of DEXA?
1. Each manufacturer comes with own model and software version
2. May require licensed technician to run scan
3. Not recommended for pregnant women
4. Some clients might not fit dimensions of bed
77
What are 5 pros of the bod pod?
1. Quick (5-10mins)
2. Requires less technician skill
3. Requires minimal client cooperation
4. Reliable (0.9-0.96)
5. Appropriate with hydrophobic clients
78
What are 4 cons of the bod pod?
1. Size restriction because of chamber size
2. May be more suitable in clinical settings
3. Must have approved clothing and swim cap
4. No beards
