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!
The biguanide metformin is widely used for the treatment of type 2 diabetes. Metformin has also been shown to slow the progression from pre to full-blown type 2 diabetes. Moreover, metformin can reduce weight gain associated with psychotropic medications and polycystic ovary syndrome.
Now, a randomised controlled trial by M P van der Aa and colleagues from the Netherlands, published in Nutrition & Diabetes suggests that long-term treatment with metformin may stabilize body weight and improve body composition in adolescents with obesity and insulin resistance.
The randomised placebo-controlled double-blinded trial included 62 adolescents with obesity aged 10–16 years old with insulin resistance, who received 2000 mg of metformin or placebo daily and physical training twice weekly over 18 months.
Of the 42 participants (mean age 13, mean BMI 30), BMI was stabilised in the metformin group (+0.2 BMI unit), whereas the control group continued to gain weight (+1.2 BMI units).
While there was no significant difference in HOMA-IR, mean fat percentage reduced by 3% compared to no change in the control group.
Thus, the researcher conclude that long-term treatment with metformin in adolescents with obesity and insulin resistance can result in stabilization of BMI and improved body composition compared with placebo.
Given the rather limited effective options for addressing childhood obesity, this rather safe, simple, and inexpensive treatment may at least provide some relief for adolescents struggling with excess weight gain.
We live in a time where most of us complain about the lack of it. Thus, I often remind myself that our “fast-food culture” is more a time than a food problem.
Now a study by Viral Patel and colleagues, published in OBESITY, takes a detailed look at how US Americans spend their time according to different BMI categories.
The researchers analyse data from over 28,503 observations of individuals aged 22 to 70 from the American Time Use Survey, a continuous cross-sectional survey on time use in the USA.
In a statistical model that adjusted for various sociodemographic, geographic, and temporal characteristics, younger age; female sex; Asian race; higher levels of education; family income >$75 k; self-employment; and residence in the West or Northeast census regions were all associated with a lower BMI relative to reference categories whereas age 50 to 59 years; Black, Hispanic, or “other” race; and not being in the labor force were associated with a higher BMI.
That said, here are the differences in time use associated with higher BMI:
Although there were no substantial differences among BMI categories in time spent sleeping, overweight individuals experienced almost 20 fewer minutes of sleeplessness on weekends/holidays than individuals with normal weight. Furthermore, there was a U-shaped relationship between BMI and sleep duration such that BMI was lowest when sleep duration was approximately 8 h per day and increased as sleep duration became both shorter and longer. Less sleep on weekends and holidays (5 to 7 h) was also associated with higher BMI than 8 to 9 h or sleep.
There were also no major differences between BMI categories and the odds of participating in work or in the amount of time working. However, working 3-4 h on weekends/holidays was associated with the lowest BMI. Individuals with obesity were more likely to be working between 3:30 a.m. and 7:00 a.m. on weekdays than normal-BMI individuals, again perhaps cutting into restful sleep.
Individuals with obesity were less likely to participate in food and drink preparation than individuals with normal weight on weekdays but spent about the same amount of time eating or drinking as the reference category.
Interestingly, individuals with obesity were more likely than individuals with normal weight to participate in health-related self-care, and overweight individuals spent over 1 h more on weekdays than individuals with normal weight on health-related self-care and also spent an additional 15 min (almost double the time) on professional and personal care services.
While individuals with higher BMI were less likely to participate in sports, exercise, and recreation on weekdays and weekends/holidays compared with individuals with normal weight, those who did participate did not differ from individuals with normal weight in the amount of time spent participating. In contrast, overweight individuals were more likely to attend sports/recreation events during the week and spent an additional 47 min (almost 25% more) on this activity than individuals with normal weight.
Overall, there was a positive and generally linear association between time spent viewing television/movies and BMI, with individuals with obesity more likely to watch television almost all hours of the day during the week and weekends.
On weekends/holidays, individuals with obesity were more likely to participate in care for household children and household adults. It was also observed that individuals with obesity spent an additional 15 min on religious and spiritual activities on weekends/holidays, compared with normal-BMI individuals (who spent 116 min).
While these data are of interest and are largely consistent with the emerging data on the role of optimal sleep duration and the detrimental impact of sedentary activities like television viewing on body weight, we must remember that the data are cross-sectional in nature and cannot be interpreted to imply causality (as, unfortunately, the authors do throughout their discussion).
Also, no correction is made for increasing medical, mental, or functional limitations associated with increasing BMI levels, which may well substantially affect time use including sleep, work, participation in sports or work-related activities.
Thus, it is not exactly clear what lessons one can learn regarding possible interventions – it is one thing to describe behaviours – it is an entirely different thing to try and understand why those behaviours occur in the first place.
Thus, unfortunately, findings from these type of studies too often feed into the simplistic and stereotypical “obesity is a choice” narrative, which does little more than promote weight bias and discrimination.
There is no doubt that exercise is good for you and that individuals with obesity, both before and after bariatric surgery (like everyone else), would stand to benefit from increasing their levels of physical activity.
Following bariatric surgery, exercise may be particularly important not just to increase physical fitness, but also to limit the obligatory loss in muscle mass that generally accompanies weight loss.
Now, a study by David Creel and colleagues, published in OBESITY, compares three levels of exercise intervention in patients following bariatric surgery in terms of effectiveness and adherence.
A total of 150 patients undergoing bariatric surgery were randomised to either standard care (SC), pedometer use (P), or exercise counseling group (C).
The standard care group (SC) received no exercise support by the bariatric center beyond a simple educational pamphlet.
Participants in the pedometer group (P) were given a pedometer and a one-page information sheet on using the device to increase physical activity. This handout promoted the progressive attainment of 10,000 steps/day. Individuals were asked to wear their device daily and record date, steps achieved, and whether they wore the device the entire day, part of the day, or not at all. Journals were collected, but no feedback was provided.
Participants in the exercise counselling group (C) were regularly seen at the bariatric centre and counselled by a certified exercise professional using motivational intervention techniques with individual goal setting.
Based on physical activity measurements using an accelerometer over two weeks before and 2, 4, and 6 months postoperatively, there was no difference between the SC and P groups, with a statistically significant but modest increase in daily steps in the C group that emerged at 4 months and was maintained at 6 months (about 1,000 extra steps per day compared to SC).
There was no notable difference in exercise tolerance, which increased in all three groups post surgery.
No group reached the 10,000 steps/day or 150 bout-minutes/week recommended for general health
As may be expected from these rather modest results, no significant differences in weight or weight change were found between groups at any time point.
Thus, these findings suggest that handing out a pedometer and asking patients to journal their activity is no more effective in promoting physical activity, than simply handing out a pamphlet; moreover, even adding in counselling by an exercise professional adds little (if anything) to the outcome.
Although the researchers discuss the possibility that an even more intense intervention may provide more benefit, the modest findings certainly question the effectiveness of activity interventions post surgery.
Certainly, simply handing out pedometers does nothing, and adding in expensive group meetings or meetings with exercise professionals adds little more.
These finding by no means speak against the value of exercise after bariatric surgery – they just speak against the indiscriminate use of expensive healthcare resources, when they achieve little more than can be achieved by handing out a pamphlet.
Thus, following weight loss, not only does the body need fewer calories, doing the same amount of physical work uses fewer calories than before (the joke is that, if you ran 5K a day to lose weight, you have to run 10K a day to keep it off).
Now, a study by Maria Fernström and colleagues, published in Obesity Surgery, shows increased mitochondrial efficiency following bariatric surgery.
The researchers performed skeletal muscle biopsies in 11 women before and at 6 months after gastric bypass surgery.
Measurements in isolated mitochondria showed a marked increase in coupled respiration (state 3) and overall mitochondrial capacity (P/O ratio) with a non-significant increase in uncoupled (state 4) respiration.
Thus, at 6 months following gastric bypass surgery, both the mitochondrial capacity for coupled, i.e., ATP-generating, respiration increased as well as the P/O ratio improved.
As the authors note, not only would this increased “fuel efficiency” in part explain the decreased basal metabolism often associated with weight loss but also the propensity for weight regain that often follows weight-loss interventions.
Obviously, due to lack of a control group, this study does not demonstrate that these changes are in any way specific to weight-loss following bariatric surgery.
Also, given that the nadir of weight loss is generally not achieved until about 18 months following surgery, the changes observed in this study may not represent the maximum increase in mitochondrial efficiency to be achieved with further weight loss.