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.
Yesterday, I posted on a study suggesting that people at high risk of obstructive sleep apnea may have a harder time losing weight that people without sleep apnea.
This prompted a reader to send me a link to a study by Luciano Drager and colleagues, published in Thorax, that presents a meta-analysis of randomised controlled trials on the effect of CPAP treatment on body weight.
The authors found 25 randomised controlled trials (RCTs) enrolling over 3000 patients with OSA ranging from 1 to 48 months in duration.
Paradoxically, they report that overall CPAP is associated with a 0.5 kg weight gain compared with control therapy.
Whether this weight gain is clinically relevant or not, the key finding is that (perhaps contrary to popular belief – including my own), the data does not support the idea that commencement of CPAP treatment for sleep apnea leads to weight loss.
As for the reasons for weight gain, an accompanying editorial by Sanjay Patel has this to offer,
“The reduction in leptin levels associated with CPAP therapy may result in increased hunger if the degree of leptin resistance does not change. Another explanation is that CPAP leads to reduced energy expenditure during sleep, as work of breathing is reduced due both to a patent upper airway as well as lung volumes rising to a more efficient point on the pressure–volume curve. Removal of the anorectic effects of hypoxia also may play an important role.”
It is also not exactly clear where the additional weight goes.
“A number of trials have demonstrated no substantial impact of CPAP on visceral fat volume, although the imaging methods used may not be sensitive enough to exclude the small magnitude of weight gain observed. Improvements in growth hormone and insulin-like growth factor 1 signalling with CPAP might result in increased muscle mass.13 Further studies are clearly needed to determine whether CPAP-induced weight gain represents increases in fat, lean body or water compartments.”
As for the potential health effects of the weight gain,
“The impact of 0.5 kg weight gain on health outcomes is fairly minimal and so should not change decision making regarding the use of CPAP in symptomatic OSA. However, it does give one pause regarding the use of CPAP in asymptomatic OSA where a cardiovascular benefit of CPAP has yet to be definitively established and makes more urgent the need for RCTs adequately powered to assess meaningful outcomes in this population.”
Clearly, the relationship between sleep apnea and body weight is a fair bit more complex than I would have thought.
Also, whether or not treating sleep apnea actually makes it easier for patients to lose weight (if they get adequate obesity treatment) remains to be seen.
Now, the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO), has published a new Position Statement on indications for surgery for obesity and weight-related diseases, published in Obesity Surgery.
Recommendations are graded based on the strength of the current evidence.
Recommendations with the highest strength of evidence include the following:
- Surgery for obesity and weight-related diseases is a codified discipline that has proven to be effective in the treatment of obesity resulting in long-term weight loss, improvement in or resolution of comorbidities, and the lengthening of life expectancy. (Level of evidence 1, grade of recommendation A)
- Surgery for obesity and weight-related diseases is a safe and effective therapeutic option for the management of T2DM in patients with obesity. Along with optimal medical treatment and lifestyle adjustment, it has been demon- strated that surgery for obesity and weight-related diseases can achieve a better glycemic control, lower glyco- sylated hemoglobin, and reduction of diabetes medications than optimal medical and lifestyle treatment alone. (Level of evidence 1, grade of recommendation A)
- Surgery for obesity and weight-related diseases demonstrated an excellent short- and midterm risk/benefit ratio in patients with class I obesity (BMI 30–35 kg/m2) suffering from T2DM and/or other comorbidities.
(Level of evidence 1, grade of recommendation A)
- Obesity, and visceral obesity in particular, is a major modifiable risk factor for cardiovascular diseases (CVD). Weight loss induced by surgery has been shown to reduce CVD risk, with the most relevant reductions in risk ob- served in the group of patients having the higher CVD risk before surgery. These patients obtain the most significant metabolic improvements thereafter. (Level of evidence 1, grade of recommendation A)
- Weight loss induced by surgery for obesity and weight- related diseases is associated to a reduction in the inci- dence of major cardiovascular events in patients with obesity, including myocardial infarction and stroke. Event reductions are more relevant in patients with a high cardiovascular risk before surgery. (Level of evidence 1, grade of recommendation A)
- Surgery for obesity and weight-related diseases may result in resolution/improvement of obstructive sleep apnea syndrome (OSAS). (Level of evidence 1, grade of recommendation A)
- In patients undergoing surgery for obesity and weight- related diseases, weight loss results in a substantial im- provement in pain and a reduction of disability derived from joint disease. (Level of evidence 1, grade of recommendation A)
- Surgery for obesity and weight-related diseases has proven to be effective in determining the overall improvement of the quality of life of patients suffering from obesity. (Level of evidence 1, grade of recommendation A)
- The improvement in the quality of life of the patient with obesity treated by surgery for obesity and weight-related diseases is independent from the type of performed procedure. (Level of evidence 1, grade of recommendation A)
- Surgery for obesity and weight-related diseases is effective in patients with class I obesity (BMI 30–35 kg/m2) and comorbidity. (Level of evidence 1, grade of recommendation A)
In addition, there are numerous recommendations, for which the evidence is perhaps less robust but nevertheless promising.
These recommendations cover a wide range of health issues including gastroesophageal reflux disease (GERD), hepatobiliary diseases, mental health, endocrinopathies and fertility, cancer and organ transplantation, pseudotumor cerebri, chronic inflammation, urinary tract and renal function, functional status, and quality of life.
I was particularly pleased to see the statement include recommendations regarding the limitations of BMI and an extensive discussion of the Edmonton Obesity Staging System as a potential guide to better defining indications for surgery.
These are the 10 Commandments of Obesity Management for health professionals presented by the Pennington Biomedical Research Centre’s Dr. Donna Ryan, who also happens to be the President Elect of the World Obesity Federation:
- Thou shalt use BMI as part of the electronic health record, but thou shalt not use it as a diagnosis that directs treatment;
- Thou shalt consider the patients’ genetic/ethnic background as part of the BMI and waist circumference risk assessment;
- Thou shalt not treat on BMI alone. Thou shalt remember that waist circumference is a risk factor and use it and other health risks to direct treatment;
- Thou shalt not worship at the shrine of ideal weight, but rather extoll the virtue of good health and set a weight goal based on a health target;
- Nor shalt thou worship at the shrine of any one diet;
- It is your job to teach the skills training in behaviors to produce weight loss or to refer the patient to someone who can;
- Thou shalt not impugn thy patient’s willpower, but rather prescribe aids to help thy patient adhere to the diet and exercise plan;
- Thou shalt prescribe medications according to the label, and if the patients lose 5% or more, thou shalt continue those medications.
- Thou shalt refer patients for bariatric surgery, especially if they suffer metabolic complications of obesity;
- Thou shalt expect a relapse if treatments are stopped.
New Orleans, LA
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!