Blind Leading the Blind

Ignorance About Obesity Is Common and Reversible

A colleague recently asked: How do you keep doing what you do in the face of so much awful stuff? By awful stuff, she meant flagrant examples of weight bias. Like the Guardian’s recent Op-Ed by Lizzie Cernik, proclaiming “It’s not fine to be fat.” The short answer to our friend’s question is this. Bias comes – at least in part – from ignorance. And when it comes to obesity, ignorance is both common and reversible.

Obesity: 100% Controllable?

The heritability of coronary artery disease is 50%. For obesity, the number is 70%. Responding to these facts, a friend recently told us:

I appreciate the Fun Facts, but there’s another difference. Excess body fat is 100% controllable by modifying behavior; not so for artery disease.

It was a sincere belief expressed by smart person. It’s undoubtedly a common belief. But it’s completely wrong. Modifying behavior can reliably produce a five percent reduction in weight. But only with intensive support and effort. Even with all that effort, after losing five percent of their weight, many people will still have excess weight or obesity. So clearly, excess body fat is not 100% controllable by modifying behavior.

In sharp contrast, coronary artery disease is much more manageable. Drugs for high cholesterol and high blood pressure do a fine job of preventing heart attacks. Stents, angioplasty, and coronary bypass procedures can help. And for people with health insurance, it’s not a huge hassle to get these drugs and procedures when you need them. CAD is not curable. But it’s very much controllable with many options.

Obesity Is a Behavior?

And this brings us to ignorance embedded in the the American Heart Association’s goals for cardiovascular health. Circulation yesterday published a commentary by Penny Gordon-Larson and Steven Heymsfield that pointed to a fine example of ignorance about obesity. In its 2020 impact goals, AHA defines a BMI less than 25 as an “ideal health behavior.”


We’re pretty sure BMI is a physical characteristic. It might be partly a result of behavior. But that’s all. Many other factors play a big role. These days, hair color is more of a direct result of behavior than BMI. The AHA is hardly alone in making an ignorant assumption about BMI. Such assumptions are so deeply entrenched in so many places that they persist. Until we call out false assumptions and help people cure their own ignorance.

That’s our goal.

Click here for the commentary by Gordon-Larson and Heymsfield.

Blind Leading the Blind, illustration © Frits Ahlefeldt / flickr

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April 11, 2018

2 Responses to “Ignorance About Obesity Is Common and Reversible”

  1. April 11, 2018 at 10:48 am, John DiTraglia said:

    The fallacy comes from the 1st law of thermodynamics that presumes everybody can lose weight. That is true but while it’s possible to walk through fire or hold you breath until you die it’s really not practically possible. The same is true for not eating.

  2. April 13, 2018 at 3:18 pm, Paul Ernsberger said:

    Thank you. The thermodynamic cliche provides no information or insight. We might ask “Why is Lake Erie so large?”. The trivial answer is “At some time, more water flowed into the lake than flowed out of it.” This non-answer leaves us no wiser.