Brozek

Brozek is a surname of Polish origin and may refer to various individuals bearing the name. In scientific literature, the term is widely associated with the Brozek formula, a mathematical equation used to estimate body fat percentage from body density.

The Brozek formula was introduced in 1963 as part of two-component models of body composition. It provides a method to convert a measured body density into an estimate of fat mass and fat percentage. It is related to the Siri equation, but uses slightly different constants, reflecting a different underlying calibration.

The commonly cited form of the Brozek equation is: percent body fat = (4.57 / Db - 4.142) × 100, where Db is body density in grams per milliliter. It is used with body density values obtained from methods such as underwater weighing. A variant of the Siri equation is sometimes used interchangeably depending on conventions.

Limitations: The Brozek equation relies on a two-component model and assumes constant densities for fat and fat-free mass; accuracy declines for some populations or extremes of body composition. Modern body composition assessment increasingly uses methods such as dual-energy X-ray absorptiometry (DEXA), air displacement plethysmography, and multi-compartment models.

In addition to its scientific use, Brozek is also a family name found in records of Polish descent.