Obesity Care and Prevention: Best Available Evidence

Evidence is a good thing, right? And when it comes to dealing with a wicked problem like obesity, we certainly advocate for following the evidence. Most people do. And yet, we often find controversies erupting about what the best available evidence tells us we should be doing.

Evidence-Based Public Health

More and more, we hear calls for an evidence-based approach to public health. But in an upcoming review, Ross Brownson and colleagues spell out a core problem:

Although there is general agreement among practitioners and scientists on the importance of evidence-based public health, there is less clarity on the definition of evidence, how to find it, and how, when, and where to use it.

One key concept that crops up repeatedly is the idea that public health must apply the “best available evidence” rather that wait for the “best possible evidence.” But that begs a question. At what point does weak evidence become mere supposition?

Evidence-Based Obesity Care

This problem is hardly limited to public health. Evidence-based medicine has become something of a holy grail. But as Aaron Carroll pointed out recently, arguments about it erupt routinely. Critics point to the weak evidence behind many evidence-based guidelines as a problem. On top of that, they contend that “cookbook medicine” discounts the artfulness required to care for an individual patient’s needs.

In obesity care, these problems are especially acute. Obesity presents complex clinical problems. The disease comes in many different forms and a one-size-fits-all approach seldom works well. A skilled obesity care provider can deliver good outcomes. But it often requires an iterative approach to find what will work.

Making Decisions with Less than Perfect Evidence

Ultimately, both public health professionals and clinical professionals have to make decisions based upon the best available evidence. One thing is clear, though. Hierarchies for scientific evidence have been well established for some time now. Criteria for assessing cause and effect date to the 1960s. We might debate and refine these criteria, but dismissing them would be unwise.

Many good reasons can justify moving forward with a course of treatment or a policy in the absence of solid evidence about the effect it will have. People make decisions based on values and suppositions all the time.

However, the real problem comes when we try to support such decisions with distorted representations of evidence. Nutrition programs can be very effective for improving the quality of nutrition in a community. But they might or might not have an effect on obesity rates.

Mindfulness techniques might help patients achieve a better sense of control over how they eat. But by itself, mindfulness might not change their weight status.

We can stick with the facts and still make decisions in the absence of perfect information.

Click here for more on evidence-based public health and here for more on evidence-based medicine.

Evidence, photograph © Phil Roeder / flickr

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January 6, 2018