Three Sources of Obesity Confusion

Delivering the 2015 Blackburn Lecture in obesity medicine Friday, David Allison presented an engaging description of three sources for obesity confusion in the application of evidence to policymaking. While describing considerable advancement in the evidence base for obesity, Allison pointed to persistent myths and presumptions that get in the way of making policies that reflect what is really known about obesity.

He zeroed in on three different sources for the confusion:

  1. Deception. A harsher description would be fraud. In one recent example, a science journalist concocted a study that purported to show chocolate could help in weight loss. He collected actual data in a flawed design, conducted a flawed analysis, and submitted the study to a journal that he expected would publish it without careful review. His point was that many flawed studies in nutrition and obesity can be and are being published. Writing in ScienceNews, Rachel Ehrenberg called his tactics an “ethically reprehensible con.” Regardless, it certainly serves as a relevant example of deception.
  2. Distortion. Amélie Yavchitz and colleagues documented a major source of this type of confusion in a PLOS Medicine publication regarding the use of press releases to distort the findings of scientific studies. They found such distortion in about half of all press releases and media reports. They also found that the seeds for such distortion were often present in the conclusions section of the study abstracts.
  3. Gross Errors. Complex statistical methods can frequently lead to gross errors that invalidate research conclusions entirely. One such example is a grossly flawed meta-analysis of glucomannan efficacy for weight loss. The original publication contained errors that led to a conclusion of efficacy that was, in fact, not supported by the data.

Allison made an important point about the need for more attention to formulating public health policy founded upon solid evidence. We have much opportunity for progress.

Click here to download Allison’s slides.

Confusion, photograph © Bex Ross / flickr

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