Wilmore and Behnke derived several equations to estimate the body density and lean body weight in young women.
Subjects: 128 healthy female students at the University of California in Berkeley with ages from 17.8 to 47.8 years
Measurements:
(1) All skin fold thickness were taken with the subject standing.
(2) All circumferences except for the upper extremity were measured with the subject standing.
(3) All diameters were taken with the person seated.
(4) Skin fold thickness was taken with a Lang skin-fold caliper with a caliper pressure of 10 grams per square mm.
(5) Diameters except for the wrist were measured with a broad-blade Bayer-Rue anthropometer. The wrist was measured with a vernier caliper.
Estimates of Body Density
Equation 1 (R value 0.676)
body density in grams per cubic cm =
= 1.06234 - (0.00068 * (scapula skin fold thickness in mm)) - (0.00039 * (triceps skin fold thickness in mm)) - (0.00025 * (thigh skin fold thickness in mm))
Equation 2 (R value 0.739)
body density in grams per cubic cm =
= 1.065551 + (0.0112 * (wrist diameter in cm)) - (0.00055 * (maximum abdominal circumference in cm)) - (0.00082 * (hip circumference in cm)) - (0.00159 * (extended biceps circumference in cm) + (0.00362 * (forearm circumference in cm))
Equation 3 (R value 0.755)
body density in grams per cubic cm =
= 1.07685 - (0.00063 * (scapula skin fold thickness in mm)) - (0.00336 * (knee diameter in cm)) + (0.00227 * (neck circumference in cm)) - (0.00049 * (minimum abdominal circumference in cm)) - (0.00043 * (maximum abdominal circumference in cm))
Estimates of Lean Body Weight
Equation 4 (R value 0.916)
lean body weight in kilograms =
= 8.629 + (0.680 * (body weight in kilograms)) - (0.163 * (scapula skin fold in mm)) - (0.1 * (triceps skin fold in mm)) - (0.054 * (thigh skin fold in mm))
Equation 5 (R value 0.922)
lean body weight in kilograms =
= 8.987 + (0.732 * (body weight in kilograms)) + (3.786 * (wrist diameter in cm)) - (0.157 * (maximum abdominal circumference in cm)) - (0.249 * (hip circumference in cm)) + (0.434 * (forearm circumference in cm))
Equation 6 (R value 0.929)
lean body weight in kilograms =
= 1.661 + (0.668 * (body weight in kilograms)) - (0.158 * (scapula skin fold in mm)) - (0.081 * (triceps skin fold in mm)) + (0.555 * (neck circumference in cm)) - (0.141 * (maximum abdominal circumference in cm))
Siri Equation
percent body fat =
= (((4.95 / (body density in grams per cubic cm)) - 4.5) * 100
