Sleep’s role in weight loss remains a mystery

Does the story adequately quantify the benefits of the treatment/test/product/procedure?

Not Satisfactory

Again, there are no interventional trials discussed, only biological studies of hormones, so benefits shouldn’t be relevant. But by passing along Aziz and Vorona’s recommendations, the author claims that these interventions have weight loss benefits. Those benefits are not quantified.

One could say that the benefits can’t be quantified because there are no studies. And that’s the point.

Does the story seem to grasp the quality of the evidence?

Not Satisfactory

The story is puzzling. In the first half, the author is keen to evaluate the quality of evidence, providing strong caveats on several dimensions of the evidence base for this question. Then for some reason, in the second half it opens the corral to allow an alternative medicine physician and sleep researcher to prescribe readers detailed behavioral changes to help them lose weight. But the story just said there’s no evidence for such interventions. It even says that Michael Aziz is making a leap from the basic research, Robert Vorona has not even been able to conduct research on this question, and that Vorona is uncertain. Why question the evidence and then prescribe health changes that, we can only conclude, have no underlying evidence? The first half says that nobody knows if the recommendations in the second half do anything for weight loss.

That’s why we say the story should’ve connected its own dots. Perhaps the story could’ve gotten away with this structure IF it added caution to interpreting the recommendations based on the lack of evidence. But it didn’t.

Does the story compare the new approach with existing alternatives?

Not Satisfactory

There are no data presented on sleep extension and related approaches as interventions for weight loss. Thus it’s impossible to compare them to other interventions for weight loss. However, we give it a strike for one reason.

The story attempts to put sleep into some kind of context in the overall mechanism of obesity by ending on the sleep researcher’s caveat that he doesn’t believe sleep deprivation is the root cause of the obesity epidemic. But he suspects it’s "part of the picture, along with lack of exercise and dietary indiscretion." The story cites no evidence or study to support his suspicion. We have no idea how big or how small a part sleep makes up in that picture. No doubt, Vorona doesn’t know either. But he is still suggesting that sleep deprivation has a role in obesity. The vague point, without evidence or relative qualification, will for some readers elevate the role of sleep deprivation relative to the other contributing factors. 

It’s relevant because each factor is associated with a weight loss intervention, and diet and exercise interventions have a warehouse of studies behind them. A brief discussion about the roles of calorie restriction and exercise for long-term weight loss and maintenance would have put the role of sleep interventions in perspective for readers.