BMI, Skinfold test

Body Mass Index (BMI)
· Body Mass Index (BMI) is a number calculated from a person’s weight and height.
· BMI is a reliable indicator of body fatness for people.
· BMI does not measure body fat directly, but research has shown that BMI correlates to direct measures of body fat, such as underwater weighing and dual energy x-ray absorptiometry (DXA).
· BMI is an inexpensive and easy-to-perform method of screening for weight categories that may lead to health problems.
· At the same BMI, women tend to have more body fat than men.
· At the same BMI, older people, on average, tend to have more body fat than younger adults.
· Highly trained athletes may have a high BMI because of increased muscularity rather than increased body fatness.
· Formula: weight (kg) / [height (m)]2
· Adult:
BMI..........................Weight Status
Underweight...........Below 18.5
Normal.....................18.5 – 24.9
Overweight..............25.0 – 29.9
Obese.......................30.0 and Above
Child (refer to charts for percentiles)
Weight Status ......................Category Percentile Range
Underweight .......................Less than the 5th percentile
Healthy weight................... 5th percentile to less than the 85th percentile
At risk of overweight......... 85th to less than the 95th percentile
Overweight .........................Equal to or greater than the 95th percentile

http://www.cdc.gov/nchs/about/major/nhanes/growthcharts/charts.htm
http://www.cdc.gov/nccdphp/dnpa/bmi/index.htm

Skinfold test
· Estimation of body fat by skinfold thickness measurement
· Can use from 3 to 9 different standard anatomical sites around the body
· The tester pinches the skin at the appropriate site to raise a double layer of skin and the underlying adipose tissue, but not the muscle.
· The calipers are then applied 1 cm below and at right angles to the pinch, and a reading taken two seconds later. The mean of two measurements should be taken.
· is best to use the sum of several sites to monitor and compare body fat measures.
· Below is a table of general guidelines for using total sum of the seven main skinfold sites (tricep, bicep, subscap, supraspinale, abdominal, thigh, calf)

Rating for NORMAL...........Male ...............Female
excellent .............................60-80 .............70-90
good ....................................81-90...............91-100
average ..............................91-110 .............101-120
below average ...................111-150 ...........121-150
poor.................................... 150+ .................150+
(Athletic scores are about 20 lower)
· Example of equations for
Males: %BF = (0.1051 x sum of triceps, subscapular, supraspinale, abdominal, thigh, calf) + 2.585, based on a sample of college students.
Females: %BF = (0.1548 x sum of triceps, subscapular, supraspinale, abdominal, thigh, calf) + 3.580, based on a sample of college students.
http://www.topendsports.com/testing/tests/skinfolds.htm