Lulu Learns Patience

Obesity and Nutrition: Learning Failures

A fascinating session on the closing day of ObesityWeek asked an important question. How can failed studies — studies with negative outcomes — become opportunities for learning from failures, instead of learning failures?

In an opening presentation, David Allison outlined the many opportunities and some failures to take the right learning away from nutrition and obesity research. Broadly, he spoke of deception, distortion, and gross errors. But he offered the most detail with examples of errors in measurement and analysis that lead to inaccurate or unwarranted conclusions. He pointed out that distortion is common. Even the New England Journal of Medicine has been seen misrepresenting research findings.

Following the presentation by Allison, Brian Elbel took a deep dive into an important example: the outcomes from years of studying the effects of adding calorie information to restaurant menus. The data are not providing the evidence that advocates have hoped for. Indeed at ObesityWeek, Jason Block and colleagues from Harvard presented a study that found no effect on calorie consumption in a controlled natural experiment over a period of four years.

In a paper just published in Health Affairs with Elbel as senior author, a team of public health experts from NYU examined the effects of five years of posting calorie counts on New York City fast-food restaurant menus. They concluded:

There were no statistically significant changes over time in levels of calories or other nutrients purchased or in the frequency of visits to fast-food restaurants. Menu labeling at fast-food chain restaurants, which the Affordable Care Act requires to be implemented nationwide in 2016, remains an unproven strategy for improving the nutritional quality of consumer food choices at the population level.

Many advocates continue to express deep faith in this strategy, despite the fact that research has shown little effect even after several years.

Faith, we are told, is the assurance of things hoped for, the conviction of things not seen. Sound health policy requires evidence in addition to faith.

Click here for Allison’s presentation.

Lulu Learns Patience, photograph © Fernando / flickr

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November 9, 2015

3 Responses to “Obesity and Nutrition: Learning Failures”

  1. November 15, 2015 at 7:42 am, Joe Gitchell said:

    Thanks, Ted, for this summary and for the pdf of Prof. Allison’s slides. Was the session recorded in any way? I still really want to get to see him present.

    And suffice to say, I would submit that the field of nicotine policy could use more of this kind of critical thinking and analysis. As just one example, but an exceptionally important one, here’s “one side” of an ongoing effort to get a research letter in NEJM retracted: . I’d welcome your thoughts on it, too—do you think Prof. Allison could be persuaded to at least skim through it?

    Keep up the good work and thank you again!


  2. November 15, 2015 at 8:21 am, Joe Gitchell said:

    Thanks, Ted–and that is a really cool offering from TOS (the on demand bit). I’m not sure I’m going to go all the way there, but it is reassuring to know that the possibility exists.