Sneaky Thief

Sneaky Bias in the Realm of Obesity

Sneaky bias has an annoyingly persistent way of creeping into obesity research. A case in point appears in Mayo Clinic Proceedings in a study that we reported last week. Though we mocked the proposition that only 3% of Americans have a healthy lifestyle, we did not call out the flaw in the study that led to this sensational claim.

The researchers defined body composition as a criteria for a healthy lifestyle.

It is no such thing. Body composition, measured in the study as body fat percentage, is a biological characteristic — not a lifestyle or behavior. The other three items lumped with with body fat percentage are indeed lifestyle behaviors: smoking, diet, and physical activity. Body composition is mostly an inherited characteristic, though it can be influenced by environment and behaviors. Did the authors intend to present us with that classic children’s game of guessing what doesn’t belong?

Probably not. More likely, they are used to mistakenly thinking that body composition (and thus obesity) is a lifestyle choice.

Body fat percentage belongs on the other side of their study’s equation — with the biomarkers they studied, like blood pressure, fasting glucose, and cholesterol.

Click here for the study, here, here, and here for more on body composition.

Sneaky Thief, photograph © Jim Bauer / flickr

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March 29, 2016

4 Responses to “Sneaky Bias in the Realm of Obesity”

  1. March 29, 2016 at 9:45 am, Stephen Phillips said:

    Unfortunately the public and the science community are often driven by social consensus and not empirical consensus. The tired stigma that an excess of adipose tissue equals an unhealthy lifestyle is a perfect example of the junk science of social consensus and obesity bias

    Stephen Phillips
    The American Association of Bariatric Counselors

    • March 29, 2016 at 10:08 am, Ted said:

      Well said, Stephen.

  2. March 29, 2016 at 1:33 pm, Carolyn said:

    Also the authors talk about normal ‘weight’ but actually used body fat percentage instead of weight, and the values that they used for normal body fat percentage were quite low, so very few people met those criteria.

    • March 29, 2016 at 5:32 pm, Ted said:

      Exactly right Carolyn. Thanks!