Concept: Obesity: Measuring Prevalence Using Body Mass Index (BMI)

Concept Description

Last Updated: 2015-05-25


Body Mass Index: A Measure of Obesity

Data Sources

Assessment of Weight in Adults

1. Lix et al. (2005)

2. Finalyson et al. (2007)

3. Fransoo et al. (2009)

4. Martens et al. (2010)

5. Fransoo et al. (2011)

BMI Corrections

    As self-reported data for height and weight are often inaccurate, Fransoo et al. (2011) derived formulae based on data and methodology from Statistics Canada to correct for this:
    Males: Corrected BMI = Self-reported BMI * 1.0531 - 0.4082
    Females: Corrected BMI = Self-reported BMI * 1.0505 + 0.0849
    These formulae were derived from simple linear regression models that predicted measured BMI values based on self-reported BMI, separately for males and females. Fransoo et al. (2011) utilized national unlinked survey data from the CCHS 3.1, subsample 2, which included both self-reported and measured height and weight. Fransoo et al. (2011) found that the resulting correction formulae increased BMI by 4% and 5% for males and females, respectively.

    Note: The corrected data reported in Fransoo et al. (2011) cannot be directly compared to non-corrected BMI values in other research.

    Fransoo et al. (2010) calculated BMI using corrected, self-reported values of height and weight from the following surveys:

    • CCHS 1.1 (2000-2001), CCHS 1.2 (2002), CCHS 2.1 (2003), CCHS 2.2 (2004), CCHS 3.1 (2005), CCHS 2007, and CCHS 2008
    • NPHS (1996-1997)
      • Only the cross-sectional survey was included.
    • HHS (1989-1990)

6. Chartier et al. (2012)

7. Martens et al. (2015)

BMI Corrections

    NPHS and CCHS:
    Males: Corrected BMI = Self-reported BMI x 1.0531 - 0.4082
    Females: Corrected BMI = Self-reported BMI x 1.0506 + 0.0850


    Males: Corrected BMI = Self-reported BMI x 0.9764 + 0.8411
    Females: Corrected BMI = Self-reported BMI x 1.0005 + 0.2095

Assessment of Weight in Youth

Brownell et al. (2001)

Brownell et al. (2008)

Fransoo et al. (2011)

More information on overweight and obesity in Manitoba children can be found in A Report on the Weight Status of Manitoba Children by Manitoba Health and Healthy Living (2007) . The same definitions of overweight and obese children from the International Obesity Task Force (Cole et al., 2000) are used by Manitoba Health as in Brownell et al. (2008) and Fransoo et al. (2011) .


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