“Recommendations for prevention of weight gain and use of behavioural and pharmacologic interventions to manage overweight and obesity in adults in primary care”From the title you might think that in it there will be guidelines for both behavioural and pharmacologic interventions to manage overweight and obesity in adults in primary care, but you’d be mistaken.
The 13 page guidelines ultimately provide only four recommendations to Canada’s family physicians, and none involve Canada's family physicians providing any actual treatment.
The guidelines recommend that Canada's family physicians measure the BMI of everyone over the age of 18 who doesn’t have an eating disorder or who is pregnant, and they refer to this as a "strong" recommendation based on "very low-quality evidence"
First off, I don’t understand how anyone can strongly recommend doing something for which there is only very low-quality evidence of benefit or utility. Moreover, why BMI? BMI is a simple measure of bigness and as such BMI does not measure the presence or the absence of health. As my friend and colleague Dr. Arya Sharma told Helen Branswell from the Canadian Press, the Task Force might have just as well have recommended we measure our patients' clothing sizes as they provide the same amount of useful information.
Choice of measurement aside, what does the Task Force tell physicians to do with the BMI they just measured? First, they tell Canadian physicians not to offer any formal interventions aimed to help prevent weight gain for their patients whose BMI's are classified as "normal" (which given we're talking about a minority of the population in fact make their weights "abnormal" if we must use that nomenclature). Next they tell physicians if their patient's BMI exceeds 27, and that patient is at risk of diabetes, they should really consider referring them to a structured behavioural intervention, and if they’re not at risk of diabetes, but have a BMI over 27, to still consider that same referral, just not quite as strongly. Lastly they tell physicians not to routinely offer any patients, of any weight, pharmacologic interventions geared to help with weight management.
Put more simply, the sum total of guidance provided by the Task Force to Canadian physicians is to measure their patients' bignesses, and if they’re concerned about their bignesses, to refer them to formal weight management programs which, if we’re talking about programs that include regulated health professionals as their providers, barely exist in Canada (full disclosure, I’m the medical director of one such program).
But here I’ll tell you something. The Task Force isn’t to blame and they didn't do anything wrong. Their guidelines quite effectively sum up some inconvenient truths about the state of the evidence when it comes to weight management.
- The medical literature still leans on BMI as if it’s a useful measure in and of itself and more patient centred approaches such as Dr. Sharma's EOSS score haven't yet been established as superior to BMI (his is).
- Despite decades of clinical study there really isn’t any gold standard approach to help medically manage a person’s weight, and frankly many of the studies that have been conducted are for programs that almost by their very definition aren't sustainable in their approaches.
- Most family doctors lack either the resources, background, or time to help patients with weight management in the context of brief, sporadic, primary care visits.
- The most successful medical weight management programs are those with structured approaches, interdisciplinary teams, frequent appointments and are of long duration.
- Medications for weight management prescribed in the absence of a behavioural intervention don't work very well
Ultimately we need to stop perpetuating the myth that scales are able to measure the presence or absence of health, because until we do so we'll be failing patients with and without obesity alike, as paradoxically, in creating clinical practice guidelines that summarize what we do and don't know about the management of weight and weight alone, those same guidelines will by definition encourage physicians to ignore, or refer onwards, the actionable lifestyle determinants of health of all of their patients.
Put more simply, health cannot be weighed.