Although “weight-loss” is a booming global multi-billion dollar business, we desperately lack effective long-term treatments for this chronic disease – the vast majority of people who fall prey to the natural supplement, diet, and fitness industry will on occasion manage to lose weight – but few will keep it off.
Thus, there is little evidence that the majority (or even just a significant proportion) of people trying to lose weight with help of the “commercial weight loss industry” will experience long-term health benefits.
When it comes to evidence-based treatments, there is ample evidence that behavioural interventions can help patients achieve and sustain important health benefits, but the magnitude of sustainable weight loss is modest (3-5% of initial weight at best).
Furthermore, although one may think that “behavioural” or “lifestyle” interventions are cost-effective, this is by no means the case. Successful behaviour change requires significant intervention by trained health professionals, a limited and expensive resource to which most patients will never have access. Moreover, there is ample evidence showing maintenance of long-term behaviour change requires significant on-going resources in terms of follow-up visits – thus adding to the cost.
This severely limits the scalability of behavioural treatments for obesity.
If for example, every Canadian with obesity (around 7,000,000) met with a registered dietitian just twice a year on an ongoing basis (which is probably far less than required to sustain ongoing behaviour change), the Canadian Health Care system would need to provide 14,000,000 dietitian consultations for obesity alone.
Given that there are currently fewer than 10,000 registered dietitians in Canada, each dietitian would need to do 14,000 consultations for obesity annually (~ 70 consultations per day) or look after approximately 7,000 clients living with obesity each year. Even if some of these consultations were not done by dietitians but by less-qualified health professionals, it is easy to see how this approach is simply not scalable to the size of the problem.
A similar calculation can be easily made for clinical psychologists or exercise physiologists.
Thus, behavioural interventions for obesity, delivered by trained and licensed healthcare professionals are simply not a scalable (or cost-effective) option.
At the other extreme, we now have considerable long-term data supporting the morbidity, mortality, and quality of life benefits of bariatric surgery. However, bariatric surgery is also not scalable to the magnitude of the problem
There are currently well over 1,500,000 Canadians living with obesity that is severe enough to warrant the costs and risks of surgery. However, at the current pace of 10,000 surgeries a year (a number that is unlikely to dramatically increase in the near future), it would take over 150 years to operate every Canadian with severe obesity alive today.
This is where we have to look at how Canada has made significant strides in managing the millions of Canadians living with other chronic diseases?
How are we managing the over 5,000,000 Canadians living with hypertension?
How are we managing the over 2.5 million Canadians living with diabetes?
How are we managing the over 1.5 million Canadians living with heart disease?
The answer to all is – with the help of prescription medications.
There are now millions of Canadians who benefit from their daily dose of blood pressure-, glucose-, and cholesterol-lowering medications. The lives saved by the use of these medications in Canada alone is in the 10s of thousands each year.
So, if millions of Canadians take medications for other chronic diseases (clearly a scalable approach), where are the medications for obesity?
Sadly, there are currently only two prescription medications available to Canadians (neither scalable, one due to cost the other due to unacceptable side effects).
So what would it take to find treatments for obesity that are scalable to the magnitude of the problem?
More on that in tomorrow’s post.
Behavioural interventions (generally aimed at reducing caloric intake and/or increasing expenditure) are notoriously unsuccessful as a strategy for sustainable weight loss in the vast majority of people (at any weight).
For the few, who do succeed (and the word “succeed” is used here rather loosely), it takes nothing short of constant (daily) diligence and ongoing determination to make it work – any reduction in effort is immediately “punished” by weight regain – even after years of successful weight-loss maintenance.
Yet, the scientific literature abounds with study after study after study with one behavioural strategy (diets are behaviours!) after the next to try and achieve the almost impossible – sustainable weight loss.
The simple reason why behavioural measures fail is because they are up against a powerful array of neuroendocrine defences that our bodies can harness to effectively sabotage our efforts.
Any time we try to wander off into negative energy balance, our bodies instantly respond with opposing increases in appetite and reduction in energy expenditure to defend and restore energy stores.
That is simply the reality of human (=animal) physiology.
However, this does not mean that behavioural interventions in obesity management are useless.
Indeed, if behaviours are causing weight gain, then changing those behaviours is in fact the first step in addressing ongoing weight gain.
So, if drinking two litres of sugary pop a day or eating most of your food out of boxes is contributing to your weight gain, then changing your diet can stop the gain.
If sitting at your desk (or on your couch) all day is contributing to your weight gain, then increasing your activity levels can stop the gain.
The critical part of the preceding two sentences is “stop the gain”.
When you identify and address the cause of weight gain, you do not automatically get weight loss – you do, however, stop the gain.
If not having breakfast contributes to your overeating (as it may well do in some individuals), then having breakfast may help you stop the gain – it does not necessarily mean that having breakfast will get you weight loss.
Thus, while I expect to see better weight control with regular breakfasts in someone who is actively gaining weight, I do not expect to see weight loss in someone who is weight stable (even if they just eat once a day).
Similarly, if binge eating disorder is contributing to ongoing weight gain, then successful treatment of that disorder should prevent further weight gain – it does not automatically reverse the process and lower your body weight.
Yes, there are behaviours that can make maintenance of weight loss more manageable – like regular weighing, keeping a food diary, managing hunger, mindfulness, etc. but by themselves, these behaviours will rarely result in significant sustainable weight loss in most people.
Can healthy behaviours improve health at any weight – of course they can!
Can healthy behaviours limit further weight gain – of course they can!
Can healthy behaviours result in significant sustainable weight loss – in some people perhaps?
Let us stop overselling behavioural interventions as a “treatment” for obesity, when in real-life, they are supportive at best.
That doesn’t make behavioural interventions any less valuable – patients can sure use all the support they can get.
Every two years the Canadian Obesity Network holds its National Obesity Summit – the only national obesity meeting in Canada covering all aspects of obesity – from basic and population science to prevention and health promotion to clinical management and health policy.
Anyone who has been to one of the past four Summits has experienced the cross-disciplinary networking and breaking down of silos (the Network takes networking very seriously).
Of all the scientific meetings I go to around the world, none has quite the informal and personal feel of the Canadian Obesity Summit – despite all differences in interests and backgrounds, everyone who attends is part of the same community – working on different pieces of the puzzle that only makes sense when it all fits together in the end.
The 5th Canadian Obesity Summit will be held at the Banff Springs Hotel in Banff National Park, a UNESCO World Heritage Site, located in the heart of the Canadian Rockies (which in itself should make it worth attending the summit), April 25-29, 2017.
Yesterday, the call went out for abstracts and workshops – the latter an opportunity for a wide range of special interest groups to meet and discuss their findings (the last Summit featured over 20 separate workshops – perhaps a tad too many, which is why the program committee will be far more selective this time around).
So here is what the program committee is looking for:
- Basic science – cellular, molecular, physiological or neuronal related aspects of obesity
- Epidemiology – epidemiological techniques/methods to address obesity related questions in populations studies
- Prevention of obesity and health promotion interventions – research targeting different populations, settings, and intervention levels (e.g. community-based, school, workplace, health systems, and policy)
- Weight bias and weight-based discrimination – including prevalence studies as well as interventions to reduce weight bias and weight-based discrimination; both qualitative and quantitative studies
- Pregnancy and maternal health – studies across clinical, health services and population health themes
- Childhood and adolescent obesity – research conducted with children and or adolescents and reports on the correlates, causes and consequences of pediatric obesity as well as interventions for treatment and prevention.
- Obesity in adults and older adults – prevalence studies and interventions to address obesity in these populations
- Health services and policy research – reaserch addressing issues related to obesity management services which idenitfy the most effective ways to organize, manage, finance, and deliver high quality are, reduce medical errors or improve patient safety
- Bariatric surgery – issues that are relevant to metabolic or weight loss surgery
- Clinical management – clinical management of overweight and obesity across the life span (infants through to older adults) including interventions for prevention and treatment of obesity and weight-related comorbidities
- Rehabilitation – investigations that explore opportunities for engagement in meaningful and health-building occupations for people with obesity
- Diversity – studies that are relevant to diverse or underrepresented populations
- eHealth/mHealth – research that incorporates social media, internet and/or mobile devices in prevention and treatment
- Cancer – research relevant to obesity and cancer
…..and of course anything else related to obesity.
Deadline for submission is October 24, 2016
To submit an abstract or workshop – click here
For more information on the 5th Canadian Obesity Summit – click here
For sponsorship opportunities – click here
Looking forward to seeing you in Banff next year!
To conclude my miniseries on the recent “Clinical Discussion” on obesity, published in the New England Journal of Medicine, I now turn to the final question – does this relatively healthy 29 year-old woman with a BMI of 32 warrant treatment?
And if yes, what treatment would you recommend.
This question cannot be answered without considering the following:
Often, we tend to focus on potential benefits of treatment, and so most of us would probably approach this question by comparing the potential benefits of treatment vs. the potential risks of not treating this patient – this is often referred to as the benefit-risk ratio.
When this ratio exceeds 1 (i.e. the potential benefits of treatment outweigh the potential risks of treatment), we would recommend treatment.
One could, however, also turn this into a risk-risk ratio.
Both, the decision to treat and the decision to not-treat bear risks.
Given that the woman in this case has Edmonton Obesity Stage 1 at best (borderline hypertension?), her mortality risk over 20 years is rather low.
For one, this means that treating her obesity would likely also have rather modest benefits (if any). In fact, there is currently no proven health benefit of even just modest weight loss in a patient like her.
Thus, we would certainly want to rule out treatments that carry any potential risk.
Clearly, obesity surgery,would not even remotely enter the picture.
Even the risk of medication, although much safer than anything we may have had before, is probably too high. Although the statistical risk for severe side effects (ranging from teratogenicity to pancreatitis – depending on the chosen medication) is rather low, it may still be substantially higher than doing nothing.
This leaves us with behavioural modifications, which would pose the lowest treatment risk (although it is important to remember that the risk of behavioural treatments is not zero: exercise can result in injury, a too restrictive diet could result in nutritional problems or, as some folks fear, trigger an eating disorder).
The most conservative approach would be to reassure her that her mortality risk is indeed rather low (certainly not warranting the risk of medication).
However, treatment decisions are not only guided by mortality risk – we also need to consider quality of life.
Despite being at low medical risk, it may well be that our patient is unhappy with her weight (although we have no information in this regard other than that she has made previous attempts at weight loss).
Exploring this further would certainly require a much deeper dive into how she feels about herself – her weight may not even be the real problem here.
Can she eat better and be more active? Sure, most of us can!
Would I want to see her again, perhaps in a year or so to see how she is doing – sure, even if just to confirm that she still has EOSS 1.
Beyond that, I would be guided by the principle of “first-do-no-harm” and probably leave it at that (at least for now).
Continuing in my miniseries on the recent “Clinical Discussion” on obesity, published in the New England Journal of Medicine, I now turn to the second question that we need to answer before jumping into giving our patient any advice about managing her weight.
The first question, as discussed in yesterday’s post, is to understand the possible “root-causes” of her weight gain, as these may not only have to be targeted during treatment but can also pose important barriers to management (e.g. emotional eating, depression, lack of time, stress, etc.).
Unfortunately, as I noted yesterday, the case presentation did not provide much in terms of helping us understand, why this patient has a BMI of 32 in the first place.
Not only did we not get any information regarding her weight trajectory, we were also only told that she eats out often and is largely sedentary – not really much to go on, given that the same could be said about the vast majority of people living in the US (or in Canada), irrespective of their size or weight.
As for the second question that we now need to answer, before giving any advice, is whether or not she even has a health issue that needs to be addressed.
Thus, while we may be led to believe that her BMI of 32 in itself justifies the diagnosis of “obesity”, we must remember that BMI is a essentially a measure of body size, in fact, not much better than a dress size.
Although statistical risk for certain health problems (e.g. diabetes, hypertension, joint problems, sleep apnea, etc.) may rise with increasing BMI, this relationship is far weaker than most people think.
Indeed, as we have previously noted, as many as 25-30% of individuals in the BMI 30-35 range may have no clinically significant health impairments whatsoever. This is particularly true for younger individuals and for women – out patient just happens to be a 29 year-old female.
Thus, it is in fact not all that surprising, that the case report goes on to note that Ms Chatham has neither a history of coronary artery disease nor diabetes (which would indeed be rather unusual if did), and, apart from a marginally elevated blood-pressure, her health status is largely “unremarkable”. Although not mentioned in the case vignette, we can perhaps also assume that all her lab values are normal.
Thus, even if we assume that the blood pressure reading is reliable, this information would at best put her at an Edmonton Obesity Stage 1, a stage where her long-term mortality risk would be almost indistinguishable from “normal”.
And, if we apply the actual WHO definition of obesity (the presence of excess or abnormal body fat that impairs health), we may in fact have to bend over backwards to diagnose this woman as having obesity at all.
So if there is no relevant health impairment from her BMI of 32, why is she even concerned about her weight?
Because, as we learn from the case study, she has been told indirectly, by her friends and family, that she is “overweight.”
Which brings me back to our question at hand: does this woman even have a health problem that needs to be addressed?
My answer would be a rather enthusiastic, “not really”.
We could of course leave it at that, and simply reassure her that she is pretty healthy (although she may perhaps want to have her blood pressure rechecked in the near future).
If however, she does persist in her intention to lose weight, and continues to insist that we advise her on what she can do to improve her health (which are really two very different questions), we may need to have a much longer discussion with her.
This is something we will look at tomorrow, when we address the third question:
What would be the best management plan for this patient?