Following the recent release of the Canadian Task Force on Preventive Health Care guidelines for prevention and management of adult obesity in primary care, the Task Force yesterday issued guidelines on the prevention and management of childhood obesity in the Canadian Medical Association Journal (CMAJ).
Key recommendations include:
- For children and youth of all ages the Task Force recommends growth monitoring at appropriate primary care visits using the World Health Organization Growth Charts for Canada.
- For children and youth who are overweight or obese, the Task Force recommends that primary health care practitioners offer or refer to formal, structured behavioural interventions aimed at weight loss.
- For children who are overweight or obese, the Task Force recommends that primary health care practitioners not routinely offer Orlistat or refer to surgical interventions aimed at weight loss.
The lack of enthusiasm for the prevention of childhood obesity is perhaps understandable as the authors note that,
“The quality of evidence for obesity prevention in primary care settings is weak, with interventions showing only modest benefits to BMI in studies of mixed-weight populations, with no evidence of long-term effectiveness.”
leading the Task Force to the following statement,
“We recommend that primary care practitioners not routinely offer structured interventions aimed at preventing overweight and obesity in healthy-weight children and youth aged 17 years and younger. (Weak recommendation; very low-quality evidence)”
Be that as it may, the Task Force does recommend structured behavioural interventions for kids who already carry excess weight based on the finding that,
“Behavioural interventions have shown short-term effectiveness in reducing BMI in overweight or obese children and youth, and are the preferred option, because the benefit-to-harm ratio appears more favourable than for pharmacologic interventions.”
What caught my eye however, was the statement in the accompanying press release which says that,
“Unlike pharmacological treatments that can have adverse effects, such as gastrointestinal problems, behavioural interventions carry no identifiable risks.” (emphasis mine)
While I would certainly not argue for the routine use of orlistat (the only currently available prescription drug for obesity in Canada) in children (or anyone else), I do take exception to the notion that behavioural interventions carry no identifiable risks – they very much do.
As readers may be well aware, a large proportion of the adverse effects of medications is attributable to the wrong use of these medications – problems often occur when they are taken for the wrong indication, at the wrong dose (too high or too low), the wrong frequency (too often or too seldom), and/or when patients are not regularly monitored. In a perfect world, many medications that often lead to problems would be far less problematic than they are in the real world.
Interestingly, the same applies to behavioural interventions.
Take for example diets – simply asking a patient to “eat less” can potentially lead to all kinds of health problems from patients drastically reducing protein, vitamin and mineral intake as a result of going on the next “fad” or “do-it-yourself” diet. Without ensuring that the patient actually follows a prudent diet and does not “overdo” it, which may well require ongoing monitoring, there is very real potential of patients harming themselves. There is also the real danger of promoting an eating disorder or having patients face the negative psychological consequences of yet another “failed” weight-loss diet. Exactly how many patients are harmed by well-meant dietary recommendations is unknown, as I am not aware of any studies that have actually looked at this.
The same can be said for exercise – simply asking a patient to “move more” can result in injury (both short and long-term) and coronary events (in high-risk patients). Again, ongoing guidance and monitoring can do much to reduce this potential harm.
In short when patient apply behavioural recommendations at the wrong dose (too much or too less), wrong frequency (too often or too seldom), and/or are not regularly monitored, there is indeed potential for harm – I would imagine that this potential for harm is of particular concern in kids.
This is not to say that we should not use behavioural interventions – we should – but we must always consider the potential for harm, which is never zero.
I’d certainly be interested in hearing from anyone who has seen harm resulting from a behavioural intervention.
On the last day of the 8th Annual Obesity Symposium here in Norderstedt, Germany, Marco Bueter from the University of Zurich presented a fascinating series of studies (just published in Circulation), demonstrating the “weight-independent” benefits of gastric bypass surgery on endothelial function (using an animal model).
Besides showing that 8 days after bypass surgery rats with diet-induced obesity had higher plasma levels of bile acids and GLP-1, that were associated with improved endothelium-dependent relaxation, not seen in sham-operated weight matched controls, but also that these effects could be prevented by blocking GLP-1 receptors with exendin 9-39.
In contrast, similar effects to those seen on vascular function in bypass rats were seen in sham-operated rats treated for 8 days with the GLP-1 analogue, liraglutide, or as the authors describe it,
“liraglutide restored NO bioavailability and improved endothelium-dependent relaxations and HDL endothelium-protective properties, mimicking the effects of RYGB”
Together these studies suggest that GLP-1 may well play an important causal role in the improved vascular function seen in patients undergoing gastric bypass surgery.
These findings are all the more interesting as liraglutide has now been approved for obesity treatment in the USA, Canada and Europe.
While these data are certainly not enough to describe liraglutide as “surgery in a pen”, they are indeed promising in terms of potential benefits of this treatment that may well be weight independent.
All the more reason to anticipate the outcome of the ongoing LEADER trial, which is currently evaluating the effect of liraglutide treatment on cardiovascular outcomes in patients with type 2 diabetes.
Disclaimer: I have served as a paid consultant and speaker for Novo Nordisk, the maker of liraglutide.
As was pointed out, even in the best hands, 10 to 20% of patients undergoing bariatric surgery will “fail”, often prompting surgeons to reoperate.
As I write this post, I am watching live “re-do” surgery on a patient who had an open Mason vertical-banded gastroplasty in 1987 (remining us that bariatric surgery has been around far longer than many people think).
Listening to the surgeon (Dr. Bruno Dillemans, Bruges, Belgium) commenting on the operation, it is apparent (even to a non-surgeon like myself), that this kind of surgery can be most challenging.
With the vast increase in the number of patients undergoing bariatric surgery worldwide, it is easy to see that bariatric “re-do” surgery will pose a significant challenge down the road.
Over the past few months, I have been working with mdBriefCase, a major provider of free online accredited continuing medical education, to produce interactive modules for obesity management.
The modules are aimed at practitioners working in primary care and pharmacists and align closely with the Canadian Obesity Network’s 5As of Obesity Management framework.
The accredited course (Mainpro M1 and MOC Section 1 or 3 credits) is available free of charge to all Canadian Health Professionals.
To access the course for physicians and allied health practitioners on mdBriefCase – click here
To access the course for pharmacists on rxBriefCase – click here
Unfortunately, judging by a randomised-controlled trial by Aidon Gribbon and colleagues from the University of Ottawa, published in the American Journal of Clinical Nutrition, this remains but a dream.
For this study, 26 male adolescents were randomised to three 1-hour sessions of rest, seated video game and an active video game. This was each followed by an ad libitum lunch. The researchers also asked the subjects to complete dietary records for another 3 days
Energy expenditure was measured by using portable indirect calorimetry throughout each experimental condition, and an accelerometer was used to assess the subsequent 3-d period.
Although energy expenditure (as measured by indirect calorimetry) was significantly higher during the active game, there was no significant differences in energy balance at 24hrs or 3 days after the end of the game (no surprise here).
Thus, while the researchers did not see any change in appetite or food intake after the active game, they also found no difference in energy balance after 24 hrs.
Thus, the energy expended during the game was apparently fully compensated for, suggesting that active gaming may have a rather modest (if any) effect on energy balance.
As to exactly how this compensation happens – the researchers attribute this to the:
“compensatory adaptation in spontaneous physical activity occurs subsequent to playing Kinect, resulting in no significant differences in net energy expenditure over the course of 24 h. This compensation in PAEE after engaging in AVGs is consistent with results from exercise trials that showed that individuals tend to compensate for physical activity interventions by decreasing subsequent spontaneous physical activity levels”
On a positive note, the authors also did not see an expected increase in caloric intake after the games.
Whether or not active video gaming over time may lead to different effects remains to be seen.