9 - Body comp field methods

Question 1

describe the skinfold caliper measurement

Answer 1

• measure thickness of subcutaneous adipose tissue
• predictions equations have been developmd
• skill required (locations landmarked properly and properly pulling away skin from tissues)
• not for use with obese clients
• done on specific body locations/sites

Question 2

what happens if you leave the caliper on for too long?

Answer 2

• pushed fluids out of the aera, can change the width of the skinfold you’re trying to measure

Question 3

in skinfold caliper measurements, what are the assumptions?

Answer 3

• SKF is a good measure of subcutaneous fat
• distribution of fat subcutaneously and internall y is similar for all individuals within each sex
• sum of several skinfolds can be used to estimate total body fat: there is a relationship between sum of SKF and Db

Question 4

bmi greater than _ is indicative of being in obese category

Answer 4

30

Question 5

it;s not recommended to conduct skinfold measurement when obese, especially when WC is high. What are the male/female cutoffs?

Answer 5

males > 102 cm
females > 88 cm

Question 6

describe BIA

Answer 6

• simple non-invasive technique: estimate total body water
• low level electrical current passes through the bodt and measures of impedance or resistance to the current
• use some predictive equations to use FFM to calculate fat mass
• fat free tissue (more water) provides less resistance to electrical current: lower R = lower % body fat

Question 7

what are methodological errors of BIA?

Answer 7

level of hydration
- setting it up properly, don’t want hand touching torso or current will jump through skin and skip parts of body for an invalid measure

Question 8

define BIA

Answer 8

bioelectrical impedance analysis

Question 9

how does BIA work?

Answer 9

• electrodes placed on hand and foot, low electrical current passes through the body
• measures impedance/resistance to current
• current moves faster through lean mass (fastest through water) and fat will be slower
• use these results to estimate %BF

Question 10

list the 2 measures used in BIA

Answer 10

resistance and reactance

Question 11

define resistance (R) as a bia measure

Answer 11

resistance (R): opposition to current flow
*better predictor of FFM
*aka how slow the curent is moving based on tissues it’s trying to get through

Question 12

define reactance (Xc) as a BIA measure

Answer 12

reactance (Xc): opposition to current flow caused by capacitance produced by cell membrane
*cell membranes are polarized and have electrical charge, going to impede the flow of electrical signal as it moves through body

Question 13

what other BIA methods beside electrodes can measure the same things?

Answer 13

scale (lower body), handheld device (upper body), stand with metal on feet and handheld with hand

Question 14

how accurate is BIA?

Answer 14

similar to skin fold caliper

Question 15

define BMI

Answer 15

mody mass index: the ratio of body weight divided by height squared (kg/m2)
*for pounds divide by 2.2
*easy, done at clinical places and research

Question 16

define waist circumference

Answer 16

measure focuses on the centralized vs. a general pattern of fat distribution
*carrying fat mass around waist - more risk

Question 17

what’s a downside of BMI?

Answer 17

muscle weighs more than fat, so someone with lots of muscle might look more obese
*does not account for composition of BW

• just an estimate but still useful cause correlated to health outcomes

Question 18

how can we more accurately assess body composition?

Answer 18

bmi in combination with WC

Question 19

what are the classification categories of BMI

Answer 19

obese, overweight and underweight

Question 20

what factors affect BMI?

Answer 20

age, ethnicity, body build, and frame size

Question 21

how does abdominal fatness affect health outcomes?

Answer 21

individuals with increased WC values are mmore likely to have hypertension, t2d, dislipidemia, and metabolic syndrome than individuals with normal WC values regardless of weight status

Question 22

what other health measures are affected by high WC?

Answer 22

individuals with a WC above specific thresholds for men and women are at further elevated risk of coronary events and diabetes in each BMI category (exception is obese classes 2 and 3 where risk is already very high)

• a higher wc is also a marker for high risk among people with normal weight