FUDGING CONCLUSIONS ABOUT CHILDHOOD OBESITY PREVENTION
“We
have a pretty good idea of how to curb childhood obesity.” Such
convictions run deep. And because of those convictions, prevention is a
frontline strategy for dealing with childhood obesity. So, it’s
especially dispiriting when we see the scientific literature stained by a
paper that fudges conclusions about childhood obesity prevention into
“some evidence of effectiveness” reports ConscienHealth’s Ted Kyle.
In the Australian and New Zealand Journal of Public Health,
Mary Malakellis and colleagues published a report on a large obesity
prevention program called “It’s Your Move”.
Deep in the bowels of their paper, you will find that the sum of all
their data showed no effect. But, the authors did not stop there. They
picked apart the data to look for subgroups with an effect. They found
it in two of the schools they studied. So, their abstract failed to
mention finding no effectiveness in the overall results. And their
conclusion claimed “some evidence of effectiveness.”
Ted
Kyle asked biostatistics expert, Professor David Allison, about this
study. Despite the claims of effectiveness in the paper’s abstract says
Allison, the body of the paper clearly describes the findings as null.
The authors state “Models to Compare the Intervention and Comparison
Groups (i.e. All Three Intervention Schools Combined Compared to All
Three Comparison Schools Combined) … showed No Statistically Significant
Interaction Effect on Weight, Height, BMI, BMI-z and Proportion of
Overweight/obesity.” The contrary statements in the abstract are an
inappropriate use of spin as defined by Boutron et al.
They lead to distortion of the scientific record and propagation of
myths and presumptions which are all too common in the obesity domain.
Authors and journals should hold themselves to higher standards of
accurate reporting.
Null findings offer golden
opportunities for learning. You do a study and the data tells you, you
were wrong. That intervention – perhaps a wonderful prevention program –
didn’t work the way you thought it would. Maybe the study was flawed.
Or maybe the intervention just doesn’t work. Perhaps we need a new
approach. But if you ignore that null finding, you’re kidding yourself.
You might deceive others. And you get in the way of progress.
- Reports: School-based systems change for obesity prevention in adolescents: outcomes of the Australian Capital Territory ‘It's Your Move!’
- Negativity towards negative results: a discussion of the disconnect between scientific worth and scientific culture
- Contact: ConscienHealth
“Recognizing fasting plasma glucose as a key biomarker enables a new interpretation of the data from many previous studies, which could potentially lead to a breakthrough in personalized nutrition,” said Prof Arne Astrup. “The beauty of this concept is its simplicity. While we are looking into other biomarkers, it is quite amazing how much more we can do for our patients just by using those two simple biomarkers. We will continue to participate in and support research to explore additional biomarkers such as gut microbiota and genomics approaches, which may offer more insights and help to more effectively customize the right diet for specific individuals.”
- Study: Pretreatment fasting plasma glucose and insulin modify dietary weight loss success: results from 3 randomized clinical trials
- Contacts: Assistant professor Mads Fiil Hjorth: madsfiil@nexs.ku.dk Professor Arne Astrup: ast@nexs.ku.dk