Tortured Logic About Obesity Prevention

Can an ineffective program to prevent obesity be cost effective? Our first impulse is to say no. But a new paper in Obesity Science and Practice says yes. Mariette Derwig and colleagues tested a child-centered approach in Sweden. They found no effect in their well-designed study. However, this inconvenient result did not get in the way of some tortured logic about obesity prevention.

Undaunted by the lack of effect, Derwig et al ran some numbers on cost effectiveness. By so doing, they came to a surprising conclusion. They suggest this program is cost-effective, with potential for universal implementation in Swedish Child Health Services.

A Cost Effective Program with No Clinical Effect?

In order to calculate cost effectiveness, Derwig used numbers for an insignificant difference between the active and control groups in their study. In other words, they assumed the program worked, though their study showed it had no effect.

This is the logic it takes to sell an ineffective obesity prevention program.

The Desire for Discovery

What seems to be happening here is not terribly uncommon in the logic of obesity prevention. Pediatrics professor Dennis Bier explains:

“Scientists seem very reluctant to say ‘We carried out a very well designed, carefully controlled, and competently conducted clinical trial and nothing happened. Period.’”

This is because scientists want to discover something when they do research. So a null result doesn’t feel very satisfying. Commenting on this instance, Dean David Allison of the Indiana University School of Public Health tells us:

“It is perfectly reasonable for the authors to offer their opinion that the treatment is effective even though it has not been shown to be effective in their study. But they should make that clear.”

Learning What Does and Doesn’t Work

All this wishful thinking about preventing obesity is really unhelpful. As we’ve noted here, four decades of efforts to prevent obesity have not produced much in the way of visible results. And yet, we often hear from health policy advocates that they know exactly what will work to prevent obesity.

If we want to make actual progress, letting go of wishful thinking about obesity prevention would be a good first step. Then we need to get curious and serious about finding interventions that will actually have an effect.

Click here for the paper by Derwig et al and here for more about exaggerated effectiveness claims in childhood obesity studies.

The Endeavor, charcoal on paper by Félix Del Marle / WikiArt

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August 31, 2021