Assessing body fat levels in particular groups is crucial, because excess body fat plays a significant role in various metabolic disorders. The purpose of the present study is to recognize optimal sex-specific reference values of percent body fat (PBF) in a healthy Iranian population using a statistical approach to normality.

In this cross-sectional study, among the 7986 participants who had bioelectrical impedance analyzer (BIA) data, after considering the exclusion criteria, 212 healthy individuals with the age of 20–30 years old (89 men and 123 women), with the lowest PBF values, were selected from Tehran Lipid and Glucose Study (TLGS). Height, weight, waist circumference, and PBF were obtained. Data of blood tests, including the lipid and glucose profiles, were also gathered. PBF was measured using a BIA. The relation between PBF and age was evaluated using second-degree regression models. Reference values for males and females were established considering the 95th percentile values of PBF for young reference groups.

The lower values of body fat mass for men and women were 16.6 ± 4.9 and 31.1 ± 5.4 Kg, respectively and the age at the lower PBF was between 20 and 30 years. The cutoff points for PBF were 38.7% and 22.5% for women and men, respectively.

This study suggested specific PBF cutoff values for healthy Iranian adults of both sexes. More studies from different regions are required to obtain reference values for populations, enabling researchers to provide more reliable reports regarding obesity cutoff points.