Fast Food Art

Fast Food Cause and Effect

Why is cause and effect such a tough concept for health reporters? The Washington Post screamed in a headline Friday about finding “an alarming new side effect from eating fast food.” The reported side effect is exposure to phthalates – chemicals used in plastics and suspected to be endocrine disruptors.

The Post’s headline was wrong. After publication, the editors changed “alarming” to “striking,” but they missed the real problem. The real problem was describing an “effect” when none had been found. Ami Zota and colleagues said so plainly in their paper that stimulated this report:

We cannot infer a causal relationship between fast food consumption and urinary phthalate metabolites.

Their study examined NHANES data and found an association between self-reported fast food consumption and higher level of phthalates detected in urine. Phthalates are linked to an increased risk of obesity and other adverse health effects. FDA is currently reconsidering the safety of phthalates for use in food packaging and food handling.

But the Post and numerous other sources are misleading their readers when they suggest that fast food gives you “a side of  industrial chemicals with that hamburger.” Both phthalates and fast food are linked to obesity. So it’s not surprising to find them coincidentally together. And this observation tells us nothing about cause and effect.

The biggest problem with fast food is its poor nutritional quality. Phthalates are a separate concern.

In all fairness, George Washington University’s PR department bears responsibility, too. Eager to pimp the university’s research, they issued a press release that suggested a finding of cause and effect where none exists.

Claiming cause and effect when it has not been found is sensational, unprofessional, and profoundly misleading to the public seeking good health information.

Click here for the Washington Post story and here for the study that prompted it.

Fast Food Art, photograph © Philip Dygeus / flickr

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April 18, 2016

5 Responses to “Fast Food Cause and Effect”

  1. April 18, 2016 at 8:09 am, Allen F. Browne said:


    But it sells newspapers and airtime. It is “state of the art”.

    The challenge is how to report, teach, market in an honest, positive, effective way – like

    • April 18, 2016 at 8:21 am, Ted said:

      Thanks, Allen.

  2. April 18, 2016 at 10:33 am, Stephen Phillips said:

    “It is common error to infer that things which are consecutive in order of time have necessarily the relation of cause and effect.”

    Jacob Bigelow
    US botanist, author of the first American textbook on botany, 1787-1879

    Stephen Phillips
    American Association of Bariatric Counselors

  3. April 18, 2016 at 10:53 am, Joe Gitchell said:

    Ted – this sure seems like a slam-dunk for the folks….

    Lame. Not sure how we all dial this back, however — so prevalent to make these leaps. Our evolution of pattern-recognizers is not always a good thing!


  4. April 18, 2016 at 11:19 am, Charles Baker said:

    As you point out, a fundamental cause of health reporters misrepresenting statistical associations as causal originates with university – and similar – press releases. Too often, health reporters’ deadlines preclude expending the time to conduct the very investigation the reporting of such research requires. Misrepresentation of research results is a pervasive shortcoming.