October 27, 2013

Fast-food outlets and obesity

Everyone knows that areas with more fast-food stores have more overweight people, and it certainly makes sense that fast food is bad for you. Like almost everything else, though, it gets more complicated when you start looking carefully.

Firstly, earlier this year Eric Crampton wrote in NBR about some research by an economics PhD student, Rachel Webb, who was trying to take advantage of this well-known relationship to unpick some aspects of correlation vs causation in the relationship between mother’s weight and infant’s birthweight. She found that, actually, areas in New Zealand with more fast-food outlets didn’t have more obesity to any useful and consistent extent.

Secondly, there’s new research on diet and fast food using data from the big NHANES surveys in the USA.  It confirms, as you might expect, that people who eat more fast food also eat less healthily at other times.




Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »


  • avatar
    megan pledger

    I didn’t get what was going on from the NBR report but…

    The TLA seems to large as a unit of measurement. IMO people would be willing to drive across a small suburb to get takeaways so an “area unit” seems a more useful unit of measurement.

    High fructose drinks (i.e. what are available with takeaways) are associated with diabetes and gestational diabestes is associated with high birthweight babies.

    And where did the data for mother’s weight, babies weight, age, ethnicity and place of residence come from – I don’t see the DHB’s giving that away – mainly because they don’t have the expertise to anonymise it.

    4 years ago