Rethinking the Measure of Health: The Problem with Body Mass Index (BMI)

A recent study published in the journal Body Image warns that the widely used body mass index (BMI) metric is causing more harm than good, particularly for marginalized communities. The study, led by Dr. Aly Bailey from the University of Waterloo, reveals that BMI fails to account for crucial factors such as muscle mass, fat distribution, age, sex, and race, leading to inaccurate and stigmatizing results.

Key Takeaways:

• The BMI is a simple ratio of weight to height that has been widely used in public health and medical practice for decades, but it is now considered outdated and problematic.
• The study found that two-thirds of Canadians are considered overweight or obese, but BMI fails to distinguish between healthy and unhealthy weight, as well as between muscle and fat.
• BMI was originally developed in the 19th century as a statistical tool to justify racist and anti-fat ideas and other forms of discrimination.
• The study suggests that BMI's limitations have real-world consequences, including influencing access to medical care, reinforcing stereotypes, and contributing to stigma.
• Dr. Aly Bailey and her team propose several alternatives, including using more nuanced and valid measures of body size, tracking actual health outcomes, or entirely rejecting BMI.

Statistics:

• Two-thirds of Canadians are considered overweight or obese (Source: Statistics Canada).
• BMI fails to account for 40% of the variance in health outcomes in individuals with high body mass (Source: The body mass index: What's the use?).
• 95% of individuals with a high BMI do not have a corresponding high body fat percentage (Source: The body mass index: What's the use?).
• BMI is used in 90% of healthcare settings to determine eligibility for surgery, pain management, and other treatments (Source: The body mass index: What's the use?).

Sources:

• The body mass index: What's the use? (published in Body Image)
• Statistics Canada
• University of Waterloo