Body Composition Flashcards
What is anthropometry
The measurement of the body
How is body mass index calculated?
Weight (kg) / height (m^2)
What is the underweight BMI range?
<18.5
What is the normal weight BMI range?
18.5-24.9
What is the overweight BMI range?
25.0-29.9
What is the obese class 1 BMI range?
30.0-34.9
What is the obese class 2 BMI range?
35.0-39.9
What is the obese class 3 BMI range?
> 40.0
Why is BMI not an adequate measurement for some individuals
Weight-training individuals mass is made of more muscle rather than fat
Why is waist circumference important?
It assesses central obesity as visceral fat located in the abdominal region is associated with a greater health risk than peripheral fat.
What waist circumference is concerning in men
Greater than 102 cm or 40 inches
What waist circumference is concerning in women
Greater than 88 cm or 35 inches
How are indirect body measurement methods derived?
From direct methods involving cadavers
What happens as methods become further away from the direct method?
There is a greater chance of error in the estimate
How can the Population specific body composition method be inaccurate
Will be inaccurate if it is applied to individuals who differ in physical characteristics.
How are generalizable equations developed?
From diverse, heterogenous samples and account for differences in age, gender, race or ethnicity.
What is the purpose of the Siri equation
It predicts percent body fat though a generalizable equation. Individuals who are further away from the average physical characteristics can have inaccurate body fat percentages
What is the Siri equation
Body fat %= (495/body density)-450
Skinfold measurement
Predict body density from skin folds; Can assess % body fat with a standard error of estimate (SEE) of 3.5%
What kind of measurement is skinfold measurements and why?
Doubly indirect because it uses the indirect method of hydrostatic weighing to calculate water displacement and estimate fat mass
Bioelectrial impedance analysis
Simple, inexpensive, quick, non-invasive technique for measuring body composition that uses the principle that electrical currents flow at different rates through the body depending on composition. Adipose tissue/Fat slows the rate of conduction.
Dual energy x-ray absorptiometry (DEXA)
Utilizes X-ray scan to quantify the parameters of body composition. Separates the body into three chemical components: lean self tissue; fat soft tissue; bone. Results in the most accurate body fat percentage
T-score on DEXA
Compares your bone density to the average bone density of a young healthy adult of the same sex
Z score on DEXA
Compares your bone density to the average bone density of someone with the same age, sex, and race/ethnicity
How does bone density risk change?
The risk of fractures doubles with every standard deviation below normal
Accuracy definition
How close the measured value is to the true value
Precision
Represents how close measured values are to each other
Bias
Represents whether there are systemic differences between measured and true values
Athlete Triad
A syndrome of three interrelated conditions that include low energy availability, functional hypothalamic amenorrheal or hypogonadotropic hyogonadism, and osteoporosis.
Energy availability (kcal/kg)
(Dietary intake - exercise energy expenditure) / Fat free mass
Mean arterial pressure represents the ______ pressure in the arteries during a cardiac cycle
Average
