Before I begin my irate list, let me say thanks to Samantha for pointing out the great blog post by Yoni Freedhof about this just-published study, and of course thanks to Yoni Freedhof for writing said blog post, from which I’m drawing both info and inspiration for my list.
Also before I begin listing, here’s a brief blurb about a hot-off-the-presses study in the International Journal of Obesity, testing the relationship between an additional 15-minute-per-day walk/run (called The Daily Mile program) for kids and changes in their BMI (body mass index) after 12 months. The idea was this: schools in the intervention group would have teachers take their students outside to walk around the school grounds, maybe combining it with some other educational activity. The control group didn’t implement the Daily Mile program. Result: nothing. There wasn’t any statistically significant change in BMI in the intervention group. Which is entirely unsurprising, and also wasn’t the goal of the Daily Mile program to begin with. Here’s Yoni Freedhof on the subject:
It’s an odd study in that we’re talking about 15 minutes of running per day which literally no one should expect to have a marked effect on childhood obesity given both math (15 mins of children running, jogging, or walking a mile probably doesn’t even burn the calories of a single Oreo) and the fact that multiple meta-analyses have shown that even far more involved school based PE initiatives don’t have an impact on childhood obesity.
So, courtesy of Yoni, wrong thing #1:
Who thought an additional 15 minutes a day of traversing a mile would result in kids losing weight?
He goes on to make another important critical observation about the study:
And it’s a problematic study in that consequent to the wholly predictable non-exciting outcome, it’s the sort of study that might be used as a means to discourage the program’s continuation.
Thanks, Yoni, for giving us wrong thing #2:
So you’re telling me someone did a study to show how a perfectly nice school program like The Daily Mile is actually a failure at something it was never designed to succeed at? Great.
The researchers did have other plans for their study in addition to measuring effects of the Daily Mile on kid BMI. They also planned on measuring some quality of life outcomes, including “child-reported quality of life, child-wellbeing and teacher-rated academic attainment (overall attainment and attainment in maths, reading and writing)”.
However, 56% of their daily life outcomes were missing. Why? They have an answer:
This was attributable to the time commitment required to collect these data by schools. Research staff obtained anthropometric measures, whereas fitness, academic attainment and wellbeing measures were administered by school staff.
Here we go, now, with wrong thing #3: Who thought primary and middle-school teachers would have time to conduct testing of student quality of life and wellbeing in addition to their copious other work duties? Were they trained to do this? Were they paid extra? Well?
Angry bird has a point. Of course data will be missing under these circumstances. In addition, the researcher also confess the following:
The schools were provided with minimal training and advised to implement The Daily Mile… interviews with school staff indicated that The Daily Mile was largely not conducted daily, and implementation fluctuated depending on competing demands during the school year.
Thus we reach wrong thing #4: You mean to tell me that, in addition to minimal staff training, they didn’t even implement the Daily Mile on a Daily basis? Why even bother crunching this data, such as it is?
Both Yoni are in agreement with Angry Bird. First, Yoni:
As I’ve said many times, dumbing down exercise to weight management shortchanges both the benefits of exercise and the realities of weight management.
I couldn’t agree more. Physical activity is good for body and soul, and weight management is excruciatingly complex at best. They are different things. Let’s not talk about them in the same study, especially one set up like this one.
Which leads us to wrong thing #5: Can we just torpedo this wrong idea that physical activity will lead to weight loss? It leads to many good things, just not that particular one. Got it?
Here endeth the list. Have a nice day…
4 thoughts on “Five Things Wrong with the latest childhood obesity study”
Wow. On one hand, publishing non-results is a good thing – so we don’t have success bias.
On the other hand, it doesn’t sound like a well designed study if there was low compliance (not to mention other flaws), so why publish?
A looong time ago (like, decades) when I was in primary school we used to do a walk/run down the lane (it was a small rural school) 3 times per week before lessons started.
Not for weight or anything like that, just movement, to get the wriggles out of us before a day sat inside. It was definitely still happening 12 years after I left as my brother was at the same school. Just a nice routine, a walk if you wanted or run if you wanted to get the blood flowing. Lots of chatting and fresh air. (Very fresh in winter!!).
These things can just be and not be about weight.
Yes to all this! There are so many good things associated with helping kids get out and about and moving. Weight loss happens not to be one of them. This is so not a problem. As you say, “these things can just be and not be about weight”. Thanks for your comments.
As always, Catherine, great post. AND: you have literally THE BEST MEME GAME I have ever seen. Thanks!
Aww shucks… Thanks!
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