The third item on the disease definition modification checklist developed by the Guidelines International Network (G-I-N) Preventing Overdiagnosis Working Group published in JAMA Internal Medicine, pertains to the issue of why modify the disease definition at all?
With obesity being increasingly recognize as a chronic disease, it should be evident to anyone, that the current BMI-based definition of obesity, although simple (or rather simplistic), would label a substantial number of individuals as “diseased”, who may be in rather good health and, therefore, very unlikely to benefit from any obesity treatments (overdiagnosis).
On the other hand, the current BMI-based definition excludes a vast number of people, who may very well have health impairments attributable to abnormal or excess body fat, and may thus benefit from obesity treatments (underdiagnosis).
Although there have been many suggestions for replacing BMI with other anthropometric measures (e.g. waist-to-hip ratio, ponderal index, abdominal sagittal diameter, etc.), none of these measures would guarantee that the individuals identified by such measures, would indeed have health impairments attributable to abnormal or excess weight – their sensitivity and specificity, although perhaps marginally better than BMI in identifying individuals with excess body fat, would still not pass the sniff-test for a reliable diagnostic test of an actual disease.
In fact, given the diversity and heterogeneous nature of adipose tissue, even more precise measures of actual body composition (including sophisticated imaging techniques) would still not be enough to determine whether or not body fat in a given is in fact impairing health and warrants obesity treatment.
In contrast, a definition of obesity that requires the actual demonstration of health impairments (likely) attributable to abnormal or excess body fat, via a clinical assessment, would ensure that obesity is only diagnosed in individuals, who actually have a health problem and would therefore likely benefit from obesity treatments. This may well include individuals below the current BMI cut-off.
Thus, continuing to use BMI (or any other anthropometric measure or more sophisticated estimate of body fat) is simply not an option if we are serious about calling obesity a disease.
Following in the footsteps of other organisations like the American and Canadian Medical Associations, the Obesity Society, the Obesity Medical Association, and the Canadian Obesity Network, this month, the World Obesity Federation put out an official position statement on recognising obesity as a chronic relapsing progressive disease.
The position statement, published in Obesity Reviews, outlines the rationale for recognising obesity as a chronic disease and is very much in line with the thinking of the other organisations that have long supported this notion.
In an accompanying commentary, Tim Lobstein, the Director of Policy at the World Obesity Federation notes, that recognising obesity as a disease can have the following important benefits for people living with this disease:
1) A medical diagnosis can act to help people to cope with their weight concerns by reducing their internalized stigma or the belief that their problems are self-inflicted and shameful.
2) A classification of obesity as a disease, or disease process, may help to change both the public and professional discourse about blame for the condition, the latter hopefully encouraging greater empathy with patients and raising the patient’s expectations of unbiased care.
3) Recognition of obesity as a disease may have benefits in countries where health service costs are funded from insurance schemes that limit payments for non-disease conditions or risk factors.
While all of this is great, and I am truly delighted to see the World Obesity Federation come around to this statement, I do feel that the policy statement seems rather tightly locked into the notion that obesity (or at least most of it) is a disease “caused” primarily by eating too much, with the blame placed squarely on the “toxic obesogenic environment”.
Personally, I would rather see obesity as a far more etiologically heterogenous condition, where a wide range of mental, biological and societal factors (e.g. genetics, epigenetics, stress, trauma, lack of sleep, chronic pain, medications, to name a few) can promote weight gain in a given individual.
Although these factors may well operate through an overall increase in caloric consumption (or rather, a net increase in energy balance), they, and not the act of overeating per se must be seen as the underlying “root causes” of obesity.
Thus, I tend to see “overeating” (even if promoted by an obesogenic food environment) as a symptom of the underlying drivers rather than the “root cause”.
Thus, saying that obesity is primarily caused by “overeating” is perhaps similar to saying that depression is primarily caused by “unhappiness”. Readers would probably agree that such a statement regarding the etiology of depression would make little sense, as “unhappiness” is perhaps a symptom but hardly the “cause” of depression, which can be promoted by a wide range of biological, environmental and societal factors, all resulting in the underlying biology that results in the mood disorder.
Similarly, I would say that there are indeed a number of complex socio-psycho-biological factors that underly the biology that ultimately results in overeating and excess weight gain (the food environment clearly being one of these factors).
While this may seem like semantics, I do think that a more differentiated look at the underlying etiology of obesity at the individual level (rather than simply blaming it all on “overeating”), is essential for promoting a more sophisticated view of this complex chronic disease both at the level of the individual and the population.
This morning, I am presenting a plenary talk in Berlin to about 200 colleagues involved in childhood obesity prevention.
The 1-day symposium is hosted by Plattform Ernährung und Bewegung e.V. (Platform for Nutrition and Physical Activity), a German consortium of health professionals as well as public and private stakeholders in public health.
Although, as readers are well aware, I am by no means an expert on childhood obesity, I do believe that what we have learnt about the complex socio-psycho-biology of adult obesity in many ways has important relevance for the prevention and management of childhood obesity.
Not only do important biological factors (e.g. genetics and epigenetics) act on the infant, but, infants and young children are exposed to the very same societal, emotional, and biological factors that promote and sustain adult obesity.
Thus, children do not grow up in isolation from their parents (or the adult environment), nor do other biological rules apply to their physiology.
It should thus be obvious, that any approach focussing on children without impacting or changing the adult environment will have little impact on over all obesity.
This has now been well appreciated in the management of childhood obesity, where most programs now take a “whole-family” approach to addressing the determinants of excess weight gain. In fact, some programs go as far as to focus exclusively on helping parents manage their own weights in the expectation (and there is some data to support this) that this will be the most effective way to prevent obesity in their offspring.
As important as the focus on childhood obesity may be, I would be amiss in not reminding the audience that the overwhelming proportion of adults living with obesity, were normal weight (even skinny!) kids and did not begin gaining excess weight till much later in life. Thus, even if we were somehow (magically?) to completely prevent and abolish childhood obesity, it is not at all clear that this would have a significant impact on reducing the number of adults living with obesity, at least not in the foreseeable future.
Let us also remember that treating childhood obesity is by no means any easier than managing obesity in adults – indeed, one may argue that effectively treating obesity in kids may be even more difficult, given the the most effective tools to managing this chronic disease (e.g. medications, surgery) are not available to those of us involved in pediatric obesity management.
Thus, I certainly do not envy my pediatric colleagues in their struggles to provide meaningful obesity management to their young clients.
I am not sure how my somewhat sobering talk will be received by this public health audience, but then again, I don’t think I was expected to fully toe the line when it comes to exclusively focussing on nutrition and activity (as important as these factors may be) as an effective way to prevent or even manage childhood obesity.
Based on the failing access to obesity care for the overwhelming majority of the 6,000,000 Canadians living with obesity in our publicly funded healthcare systems, the 2017 Report Card on Access To Obesity Treatment For Adults, released the 5th Canadian Obesity Summit, has the following 7 recommendations for Canadian policy makers:
- Provincial and territorial governments, employers and the health insurance industry should officially adopt the position of the Canadian Medical Association that obesity is a chronic disease and orient their approach/resources accordingly.
- Provincial and territorial governments should recognize that weight bias and stigma are barriers to helping people with obesity and enshrine rights in provincial/territorial human rights codes, workplace regulations, healthcare systems and education.
- Employers should recognize and treat obesity as a chronic disease and provide coverage for evidence-based obesity programs and products for their employees through health benefit plans.
- Provincial and territorial governments should increase training for health professionals on obesity management.
- Provincial and territorial governments and health authorities should increase the availability of interdisciplinary teams and increase their capacity to provide evidence- based obesity management.
- Provincial and territorial governments should include anti-obesity medications, weight-management programs with meal replacement and other evidence-based products and programs in their provincial drug benefit plans.
- Existing Canadian Clinical practice Guidelines for the management and treatment of obesity in adults should be updated to reflect advances in obesity management and treatment in order to support the development of programs and policies of federal, provincial and territorial governments, employers and the health insurance industry.
If and when any of the stakeholders adopt these recommendations is anyone’s guess. However, I am certain that since the release of the Report Cards, the relevant governments and other stakeholders are probably taking a closer look at what obesity management resources are currently being provided within their jurisdictions.
Given that things can’t really get any worse, there is hope that eventually Canadians living with obesity will have the same access to healthcare for their chronic disease as Canadians living with any other illness.
Just imagine if the question in the title of this post was, “Why would anyone want access to prescription medications for diabetes?” (or heart disease? or lung disease? or arthritis? or, for that matter, cancer?)
Why would anyone even ask that question?
If there is one thing we know for sure about obesity, it is that it behaves just like every other chronic disease.
Once you have it (no matter how or why you got it) – it pretty much becomes a life-long problem. Our bodies are so efficient in defending our body fat, that no matter what diet or exercise program you go on, ultimately, the body wins out and puts the weight back on.
In those few instances where people claim to have “conquered” obesity, you can virtually bet on it, that they are still dealing with keeping the lost weight off every single day of their life – they are not cured, they are just treated! Their risk of putting the weight back on (recidivism) is virtually 100% – it’s usually just a matter of time.
Funnily enough, this is no different from people trying to control any other chronic disease with diet and exercise alone.
Take for e.g. diabetes. It is not that diet and exercise don’t work for diabetes, but the idea that most people can somehow control their diabetes with diet and exercise alone is simply not true. No matter what diet they go on or what exercise program they follow, sooner or later, their blood sugar levels go back up and the problems come back.
You could pretty much say the same for high blood pressure or cholesterol, or pretty much any other chronic health problem (that, in fact, is the very definition of “chronic”).
So why medications for obesity?
Because, like every other chronic disease, medications can help patients achieve long-term treatment goals (of course only as long as they stay on treatment).
Simply put, if the reason people virtually always regain their lost weight (no matter how hard they try to lose it) is simply because of their body’s ability to resist weight loss and promote weight regain, then medications that interfere with the body’s ability to resist weight loss and promote weight regain, will surely make it far more likely for them to not only lose the weight but also keep it off.
Now that we increasingly understand many of the body’s mechanisms to defend against weight loss and promote weight regain (and the body has a whole bag of tricks that you are up against), then pharmacologically blocking these mechanisms makes this a manageable (fair?) fight.
This is by no means easy. Interfering with human physiology always comes at a cost – which is why we need medications that are robustly tested for safety and efficacy (which is why we are here talking about prescription medications and not the nonsense you can buy over the counter in your local drug store or health supplement outlet).
There is of course no guarantee that any one medication will work for or be tolerated by everyone – again, no different from the medications for other chronic diseases (which is why we have so many of them for the same indication).
So who has access to prescription anti-obesity medications in Canada?
Short answer – almost no one.
Thus, in the 2017 Report Card on Access To Obesity Treatment For Adults, released last week at the 5th Canadian Obesity Summit, the less than 20% of Canadians living with obesity (and that is a very generous estimate) have access to the two prescriptions medications approved by Health Canada for long-term treatment of obesity.
Thus, as far a coverage for obesity medications in Canada is concerned,
Neither anti-obesity medication (Xenical® or saxenda®) are listed as a benefit on any provincial/territorial formulary and, therefore, they are not covered under any provincial public drug benefit (or pharmacare) programs.
There may be special-access programs in some provinces that adjudicate coverage for non-formulary medications based on individual case review; however, coverage for anti-obesity medications through these programs are not guaranteed and are, in fact, rare.
Anti-obesity medications are not covered in any federal public drug benefit programs.
Again one must ask, what will it take for governments, employers, and payers to stop discriminating against Canadians living with obesity in our healthcare system?
Disclaimer: I have received honoraria for speaking and consulting for companies that make anti-obesity medications