Overview :

The U.S. Air Force used equations derived by Brennan and Fuchs et al to estimate the fat free mass of its personnel using anthropometric measurements. This can be then used to calculate the percent body fat.

Parameters:

(1) gender

(2) circumference of the flexed biceps in centimeters

(3) height in centimeters

(4) forearm circumference in centimeters

(5) body weight in kilograms

Measurements:

(1) flexed biceps circumference: Clench the fists and bend the elbow to 90°. Measure the maximum circumference of the upper arm.

(2) forearm circumference: Bend the elbow to 90°. Mark a point on the forearm 0.25 inches from the skin fold. Extend the elbow straight. Measure the circumference of the forearm at the mark.

male fat free body mass in kilograms =

= (0.018 * ((circumference of flexed biceps)^2)) + (0.514 * (height)) - 49.67

female fat free body mass in kilograms =

= (1.619 * (forearm circumference)) + (0.311 * (height)) - 47.76

percent body fat =

= ((body weight) - (fat free mass)) / (body weight) * 100%

Performance:

• For males, R = 0.84, SEE = 2.95 kg

• For females, R = 0.84, SEE = 2.29 kg

Brennan EH. Development of a binomial involving anthropometric measurements for predicting lean mass in young women. Masters thesis. Incarnate Word College, San Antonio, Texas. 1974.

Fuchs RJ, Theis CF, Lancaster MC. A nomogram to predict lean body mass in men. Am J Clin Nutrition. 1978; 31: 673-678.

Hodgdon CA. Chapter 4: Body composition in the military services: Standards and methods. pages 57-70 (Table 4-5a, page 65). IN: Marriott BM, Grumstrup-Scott J (editors). Body Composition and Physical Performance. Applications for the Military Services. National Academy Press. Washington, DC. 1992.