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.
Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.
March 29, 2016