Lab 7 Flashcards
What is obesity
complex multifactorial disease involving the interaction of physiological, metabolic, genetic, social, cultural, behavioral factors
Explain what body composition refers to
the makeup of the body – valuable to health and exercise science professionals
- risk assessment, individualization of exercise prescriptions and interventional progress
what is anthropometry
measure of the body
what does anthropometry measure
measure: body weight, height, and waist circumference
How is BMI calculated
calculated as weight (kg) / height (m^2)
* measure of ratio of body weight to height
What is one problem associated with BMI
no way to determine composition of the weight
Is BMI an adeqate measurement of disease risk
NO not an adequate measurement of disease risk for some individuals (ie. weight training individuals)
What is the importance of waist circumference in measuring central obesity
- extremely valuable
- fat located in absominal region (viceral fat) associated with greater health risk than peripheral fat == independent risk preictor when BMI is not markedly increased
should waist circumference be utilized for assessment of obesity
YES
Is there a direct in vivo method to measure the different components of the body
NO direct in vivo method
What are the indirect or doubly indirect methods to determine body composiiton
indirect method: derived from direct methods involving cadavers
doubly indirect methods: derived from indirect methods
as methods become fruther away from the direct method what happens to the error in the estimate
greater error in the estimate
What are generalizable equations
developed from diverse heterogenous samples –> account for differences in age, gender, race/ethnicity…
What is the Siri equation used for
predict percent body fat – generalizable equation
What is the equation for body fat (%)
(495/body density) - 450
what is a skinfold measurement
using skinfold caliper – assess % body fat with standard error estimate (SEE) of 3.5%
Skinfold measurements are based on what two primary assumptions
- subcutaneous fat is directly proportional to total fat
- skinfold sites selected are representative of total body subcutaneous fat
What are the major limitations of the skinfold analysis
technician training, applicability of equations to individual being tested , skinfold site measurement accuracy, measurement technique
SEE = 3.5%
What is a bioelectrical impedance analysis (BIA)
simple inexpensive technique for measureing body composition
- based on principle that electrical current flows at different rates through the body depending on its compositions
- water ions = electrical current fow
- fat = no electrical flow
- body fat causes greater resistance than fat free mass
What is A DEXA scan
Dual energy x-ray absorptiometry = utilize X-ray to scan and quantify parameters of body composiition
- differentiate body wight into 3 components
1. lean soft tissue, fat soft tissue, and bone
Can measure not only subcutaneous, and visceral, retroperitoneal, and intramuscular fat
SE = +/- 1.8%
What is a t-score
compares bone density to the average bone density of young healthy adults of the same sex
What is a z-score
compares bone density to the average bone density of someone your same age, sex, race/ethnicity
are there accepted standards for body fat
NO Standards accepted for percent body fat –> all methods of measurement and include error
What is accuracy
how close a measured value is to the true value
