The Shameful Power of a Theory of Change

Stages of Change is is a concept deeply embedded in our thinking about health behaviors and obesity. “How ready are you to change?” is the core question. But when applied to obesity care, it is a model with shameful power to promote implicit bias. A new perspective today in the New England Journal of Medicine illustrates how the concept can go terribly wrong. That’s because it often means failure in obesity care is the patient’s fault. Scott Hagen writes:

“Weight reduction, the description suggests (and many clinicians assume), is as simple as adopting permanent caloric restriction, and the failure of a person with obesity to achieve and maintain weight loss is caused by a lack of discipline.

“At every turn in my patient’s experience with the healthcare system, well-intentioned clinicians would subject him to this idea.”

Thus, he aptly labels this our culture of shame in medical care. His patient tells Hagen he’s “been bad,” declines treatment, and resolves to do better on his own. This is a patient with a long history of obesity that resists all his efforts to manage it himself. So it is keeping him from getting a knee replacement he needs.

Troubles with the Transtheoretical Model

Another name for Stages of Change is the transtheoretical model of behavior change. In fact, the stages of change is just one element of that model. Christopher Armitage writes:

“The transtheoretical model is arguably the dominant model of health behaviour change, having received unprecedented research attention, yet it has simultaneously attracted exceptional criticism.”

A 2011 Cochrane Review found no conclusive evidence for sustainable weight loss from using this model. That did not sit well with fans of this model, so a revision in 2014 found very low quality evidence that it might lead to better dietary and physical activity habits. This falls short of faint praise.

Robert West writes:

“When it comes to assessing motivation to change, it would be better to revert to simple questions about desire to change that were in place before the SOC model was developed.”

Motivational interviewing is a framework that allows clinicians to meet patients where they are, without judging their readiness – which can be a surrogate for worthiness.

Fixated on Behavior over Biology

Ultimately, the problem with stages of change is how it fits so neatly with a bias that obesity is a simple behavioral problem. If someone can’t overcome obesity, it’s just because they’re not ready to change. That’s the flawed thinking that burrows so easily into our brains.

We need fundamental changes to overcome this and health professionals should lead it. Hagan describes the necessary change perfectly:

“To fight weight bias and to expand the study and use of effective weight-loss therapies, the health professions need to transform themselves from adversaries of patients with obesity to allies.”

Click here for Hagan’s excellent commentary in NEJM.

Female Head, painting by Pablo Picasso / WikiArt

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December 16, 2021