Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1996 May;20(5):496-8.

On estimating the minima of BMI-mortality curves

D B Allison  1 , M S Faith
Affiliations
  • PMID: 8696431

On estimating the minima of BMI-mortality curves

D B Allison et al. Int J Obes Relat Metab Disord. 1996 May.

Abstract

Objective: To identify the 'optimal' BMI, that is, the BMI associated with minimal mortality, researchers frequently fit a quadratic function to data and identify the nadir of the BMI-mortality curve. However, Waaler (1984)8 has argued that this approach systematically overestimates the optimal BMI because the true curve might not be quadratic. The purpose of this study was to test this proposition.

Design: We simulated 25 decidedly nonquadratic curves in which the true minimum corresponded to a BMI of 24.

Results: When fitting a quadratic model to this data and solving for the nadir of the curve, the estimated optimal BMI was 21.14 (SD = 0.586).

Conclusions: It is concluded that there is no way of knowing a priori whether the BMI associated with minimum mortality will systematically overestimate, underestimate, or estimate in an unbiased manner the true optimal BMI when the true model underlying the data is not known.

PubMed Disclaimer

Publication types