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. 2025 Mar 17;110(4):e1103-e1107.
doi: 10.1210/clinem/dgae341.

Defining Overweight and Obesity by Percent Body Fat Instead of Body Mass Index

Adam W Potter  1 , Geoffrey C Chin  1 , David P Looney  2 , Karl E Friedl  3
Affiliations

Defining Overweight and Obesity by Percent Body Fat Instead of Body Mass Index

Adam W Potter et al. J Clin Endocrinol Metab. .

Abstract

Objective: Thresholds for overweight and obesity are currently defined by body mass index (BMI), a poor surrogate marker of actual adiposity (percent body fat [%BF]). Practical modern technologies provide estimates of %BF but medical providers need outcome-based %BF thresholds to guide patients. This analysis determines %BF thresholds based on key obesity-related comorbidities, exhibited as metabolic syndrome (MetSyn). These limits were compared to existing BMI thresholds of overweight and obesity.

Design: Correlational analysis of data from cross sectional sampling of 16 918 adults (8734 men and 8184 women) from the US population, accessed by the National Health and Nutrition Examination Survey public use datasets.

Results: Individuals measured by BMI as overweight (BMI > 25 kg/m2) and with obesity (BMI > 30 kg/m2) included 5% and 35% of individuals with MetSyn, respectively. For men, there were no cases of MetSyn below 18%BF, %BF equivalence to "overweight" (ie, 5% of MetSyn individuals) occurred at 25%BF, and "obesity" (ie, 35% of MetSyn individuals) corresponded to 30%BF. For women, there were no cases of MetSyn below 30%BF, "overweight" occurred at 36%BF, and "obesity" corresponded to 42%BF. Comparison of BMI to %BF illustrates the wide range of variability in BMI prediction of %BF, highlighting the potential importance of using more direct measures of adiposity to manage obesity-related disease.

Conclusion: Practical methods of body composition estimation can now replace the indirect BMI assessment for obesity management, using threshold values provided from this study. Clinically relevant "overweight" can be defined as 25% and 36% BF for men and women, respectively, and "obesity" is defined as 30% and 42% BF for men and women.

Keywords: BMI; body fat; body mass index; metabolic syndrome.

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Figures

Figure 1.
Figure 1.
CONSORT flow diagram for study participant data selection.
Figure 2.
Figure 2.
Prevalence of men and women in the NHANES data with ≥3 markers of metabolic syndrome by BMI.
Figure 3.
Figure 3.
Prevalence of men and women in the NHANES data with ≥3 markers of metabolic syndrome by relative %BF.
Figure 4.
Figure 4.
Comparison of BMI (kg/m2) to measured relative %BF for men and women in the NHANES data (1999-2018).
See this image and copyright information in PMC

Comment in

References

    1. Prentice AM, Jebb SA. Beyond body mass index. Obes Rev. 2001;2(3):141‐147. - PubMed
    1. Gallagher D, Heymsfield SB, Heo M, Jebb SA, Murgatroyd PR, Sakamoto Y. Healthy percentage body fat ranges: an approach for developing guidelines based on body mass index. Am J Clin Nutr. 2000;72(3):694‐701. - PubMed
    1. Heo M, Faith MS, Pietrobelli A, Heymsfield SB. Percentage of body fat cutoffs by sex, age, and race-ethnicity in the US adult population from NHANES 1999–2004. Am J Clin Nutr. 2012;95(3):594‐602. - PubMed
    1. Sakers A, De Siqueira MK, Seale P, Villanueva CJ. Adipose-tissue plasticity in health and diseases. Cell. 2022;185(3):419‐446. - PMC - PubMed
    1. Dwight EW, Rogers Oscar H, Root Edward K, et al. . Medico-actuarial mortality investigation. The association of life insurance medical directors and the actuarial society of America. 1913. Obes Res. 1995;3(1):100‐106. - PubMed