describe the skinfold caliper measurement
- 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
what happens if you leave the caliper on for too long?
- pushed fluids out of the aera, can change the width of the skinfold you’re trying to measure
in skinfold caliper measurements, what are the assumptions?
- 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
bmi greater than _ is indicative of being in obese category
30
it;s not recommended to conduct skinfold measurement when obese, especially when WC is high. What are the male/female cutoffs?
males > 102 cm
females > 88 cm
describe BIA
- 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
what are methodological errors of BIA?
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
define BIA
bioelectrical impedance analysis
how does BIA work?
- 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
list the 2 measures used in BIA
resistance and reactance
define resistance (R) as a bia measure
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
define reactance (Xc) as a BIA measure
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
what other BIA methods beside electrodes can measure the same things?
scale (lower body), handheld device (upper body), stand with metal on feet and handheld with hand
how accurate is BIA?
similar to skin fold caliper
define BMI
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
define waist circumference
measure focuses on the centralized vs. a general pattern of fat distribution
*carrying fat mass around waist - more risk
what’s a downside of BMI?
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
how can we more accurately assess body composition?
bmi in combination with WC
what are the classification categories of BMI
obese, overweight and underweight
what factors affect BMI?
age, ethnicity, body build, and frame size
how does abdominal fatness affect health outcomes?
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
what other health measures are affected by high WC?
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
