Disclaimer: no actual weight was lost in this study! Nevertheless, according to a Han Kyungsun and colleagues, in a paper published in Molecular Nutrition and Food Research, daily ingestion of fermented (but not unfermented) kimchi may result in a potentially beneficial change in the gut bacteriome profile with changes in the expression of multiple metabolic pathways (at least in circulating blood cells).
This study on 8-weeks of fermented vs. unfermented kimchi in 24 women with obesity, was prompted by the widely held assumption that fermented preserves (e.g. kimchi, sauerkraut, etc.) can have positive metabolic effects and has optimistically been linked to weight loss (although evidence for this is rather anecdotal at best).
Be that as it may, the fact that the researchers did find an effect on the relationship of firmicutes to bacteroides populations in the gut at least demonstrates that fermented foods (in this case kimchi) can indeed have a significant on gut bacteria.
How and if this results in any clinically relevant metabolic changes remains to be seen.
The recently released Canadian Practice Guidelines on the prevention and management of overweight and obesity in children and youth released by the Canadian Task Force on Preventive Health Care (CMAJ 2015), rightly recommended that surgery not be routinely offered to children or youth who are overweight or obese.
Nevertheless, there is increasing evidence that some of these kids, especially those with severe obesity, may well require rather drastic treatments that go well beyond the current clinical practice of doing almost nothing.
Just how ill kids can be before they are generally considered potential candidates for bariatric surgery is evident from a study by Marc Michalsky and colleagues, who just published the baseline characteristics of participants in the Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS) Study, a prospective cohort study following patients undergoing bariatric surgery at five adolescent weight-loss surgery centers in the United States (JAMA Pediatrics).
While the mean age of participants was 17 with a median body mass index of 50, the prevalence of cardiovascular risk factors was remarkable: fasting hyperinsulinemia (74%), elevated hsCRP (75%), dyslipidemia (50%), elevated blood pressure (49%), impaired fasting glucose levels (26%), and diabetes mellitus (14%).
Not reported in this paper are the many non-cardiovascular problems raging from psychiatric issues to sleep apnea and muskuloskeletal problems, that often dramatically affect the life of these kids.
While surgery certainly appears rather drastic, the fact that these kids are undergoing surgery is merely an indicator of the fact that we don’t have effective medical treatments for this patient population, which would likely require a combination of behavioural interventions and polypharmacy to achieve anything close to the current weight-loss success of bariatric surgery.
That this cannot be the ultimate answer to obesity management (whether for kids or adults), is evident from the rising number of kids and adults presenting with ever-higher BMI’s and related comorbidity – not all of these can or will want surgery.
Thus, while current anti-obesity medications cannot compete with the magnitude of weight-loss generally seen with surgery, medications together with behavioural interventions may well play a role in helping prevent progressive weight gain in earlier stages of the disease.
Unfortunately, I am not aware of any studies that have explored the use of medications in kids to stabilize weight in order to avoid surgery. This would, in my opinion, be a very worthwhile use of such medications.
Given that virtually every risk-factor guideline (from hypertension to diabetes) recommends “weight-loss” as “first-line” treatment, to many this may seem a rather stupid question, but in reality, there is in fact almost no high-qulaity evidence to show that intentional (non-surgical) weight loss actually reduces mortality.
This may well be simply because randomised controlled studies on intentional weight loss have either never been long enough, big enough, or able to sustain large enough differences in body weight between the interventions arms.
Nevertheless, now a meta-analysis by Stephen Kritchevsky and colleagues from the Wake Forest School of Medicine, published in PLOS one, suggests that being randomised to the intervention arm in a weight-loss study may reduce mortality by 15%.
The researchers identified 15 randomised controlled trials of behavioural interventions for weight loss of at least 18 months duration, of which 12 reported at least one death in either of the intervention arms.
These studies included 17,186 participants (53% female, mean age 52 years, mean BMI range 30–46 kg/m2 ) with follow-up times ranging from 18 months to 12.6 years (mean: 27 months), and an average weight loss of 5.5±4.0 kg.
Based on a total of 264 deaths in weight loss groups compared to 310 in non-weight loss groups, the authors calculated a 15% lower all-cause mortality risk (RR = 0.85; 95% CI: 0.73–1.00) in the weight-loss group.
Thus, the authors conclude that being randomized to the weight-loss arm in a behavioural weight-loss study may indeed reduce mortality risk.
However, as readers may realise, this study certainly does not “prove” that it is the actual weight loss that mediates these effects. After all, to achieve and sustain weight-loss through behavioural interventions, participants would have had to change their diet and activity levels to a greater extent that those in the control group. Thus it is very possible that the difference in mortality between the groups could well have been due to changes in health behaviours rather than due to the actual weight loss.
Nevertheless, the findings are reassuring in that they at least do not show an increase in mortality, something that people have feared may happen with intentional weight loss, especially in older individuals.
I guess the most we can conclude from this study is that being lucky enough to be randomised into the “weight-loss arm” of a behavioural weight-loss RCT may just help reduce your mortality risk.
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.
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