NAME:   Fitting Percentage of Body Fat to Simple Body Measurements
TYPE:   Sample
SIZE:   252 observations, 19 variables

DESCRIPTIVE ABSTRACT:
Percentage of body fat, age, weight, height, and ten body circumference
measurements (e.g., abdomen) are recorded for 252 men.  Body fat, a
measure of health, is estimated through an underwater weighing
technique.  Fitting body fat to the other measurements using multiple
regression provides a convenient way of estimating body fat for men
using only a scale and a measuring tape.

SOURCE:
The data were generously supplied by Dr. A. Garth Fisher, Human
Performance Research Center, Brigham Young University, Provo, Utah
84602, who gave permission to freely distribute the data and use them
for non-commercial purposes.  Reference to the data is made in Penrose,
et al. (1985).

VARIABLE DESCRIPTIONS:
Columns
  3 -   5  Case Number
 10 -  13  Percent body fat using Brozek's equation, 
           457/Density - 414.2
 18 -  21  Percent body fat using Siri's equation, 
           495/Density - 450
 24 -  29  Density (gm/cm^3)
 36 -  37  Age (yrs)
 40 -  45  Weight (lbs)
 49 -  53  Height (inches)
 58 -  61  Adiposity index = Weight/Height^2 (kg/m^2)
 65 -  69  Fat Free Weight 
           = (1 - fraction of body fat) * Weight, 
           using Brozek's formula (lbs)
 74 -  77  Neck circumference (cm)
 81 -  85  Chest circumference (cm)
 89 -  93  Abdomen circumference (cm) "at the umbilicus 
           and level with the iliac crest"
 97 - 101  Hip circumference (cm)
106 - 109  Thigh circumference (cm)
114 - 117  Knee circumference (cm)
122 - 125  Ankle circumference (cm)
130 - 133  Extended biceps circumference (cm)
138 - 141  Forearm circumference (cm)
146 - 149  Wrist circumference (cm) "distal to the 
           styloid processes"

SPECIAL NOTES:
The data are as received from Dr. Fisher.  Note, however, that there
are a few errors.  The body densities for cases 48, 76, and 96, for
instance, each seem to have one digit in error as can be seen from the
two body fat percentage values.  Also note the presence of a man (case
42) over 200 pounds in weight who is less than 3 feet tall (the height
should presumably be 69.5 inches, not 29.5 inches)!  The percent body
fat estimates are truncated to zero when negative (case 182).

PEDAGOGICAL NOTES:
These data can be used to show the utility of multiple regression and
to provide practice in model building.

Additional information about these data can be found in the "Datasets
and Stories" article "Fitting Percentage of Body Fat to Simple Body
Measurements" in the _Journal of Statistics Education_ (Johnson 1996).

REFERENCE:
Penrose, K., Nelson, A., and Fisher, A. (1985), "Generalized Body
Composition Prediction Equation for Men Using Simple Measurement
Techniques" (abstract), _Medicine and Science in Sports and Exercise_,
17(2), 189.

SUBMITTED BY:
Roger W. Johnson
Department of Mathematics and Computer Science
Carleton College
Northfield, MN  55057-4001
rjohnson@carleton.edu