The neuronal control of appetite and food intake is among the most complex and fascinating systems.
Now, in a paper published in Science, Xiaobing Zhang and Anthony van den Pol from Yale University, New Haven, report the identification of a novel role of the zona incerta in inducing profound binge eating behaviour in mice.
The zona incerta, is a little know part of the central nervous system within the subthalamus with extensive projections all the way from the cerebral cortex into the spinal cord. It is thought to play an important role in limbic-motor integration as well as synchronizing brain rhythms.
The researchers showed that optogenetic stimulation of zona incerta GABA neurons or their axonal projections to paraventricular thalamus excitatory neurons rsults in an immediate (in 2 to 3 seconds) binge-like eating behaviour – the animals ate up to 35% of their total energy requirements in just 10 mins.
Furthermore, while intermittent stimulation of these neurons led to body weight gain, ablation reduced weight.
The authors suggest that the identification of this novel orexigenic system may lead to better treatments not just for binge-eating disorder.
This morning, I am presenting a plenary talk in Berlin to about 200 colleagues involved in childhood obesity prevention.
The 1-day symposium is hosted by Plattform Ernährung und Bewegung e.V. (Platform for Nutrition and Physical Activity), a German consortium of health professionals as well as public and private stakeholders in public health.
Although, as readers are well aware, I am by no means an expert on childhood obesity, I do believe that what we have learnt about the complex socio-psycho-biology of adult obesity in many ways has important relevance for the prevention and management of childhood obesity.
Not only do important biological factors (e.g. genetics and epigenetics) act on the infant, but, infants and young children are exposed to the very same societal, emotional, and biological factors that promote and sustain adult obesity.
Thus, children do not grow up in isolation from their parents (or the adult environment), nor do other biological rules apply to their physiology.
It should thus be obvious, that any approach focussing on children without impacting or changing the adult environment will have little impact on over all obesity.
This has now been well appreciated in the management of childhood obesity, where most programs now take a “whole-family” approach to addressing the determinants of excess weight gain. In fact, some programs go as far as to focus exclusively on helping parents manage their own weights in the expectation (and there is some data to support this) that this will be the most effective way to prevent obesity in their offspring.
As important as the focus on childhood obesity may be, I would be amiss in not reminding the audience that the overwhelming proportion of adults living with obesity, were normal weight (even skinny!) kids and did not begin gaining excess weight till much later in life. Thus, even if we were somehow (magically?) to completely prevent and abolish childhood obesity, it is not at all clear that this would have a significant impact on reducing the number of adults living with obesity, at least not in the foreseeable future.
Let us also remember that treating childhood obesity is by no means any easier than managing obesity in adults – indeed, one may argue that effectively treating obesity in kids may be even more difficult, given the the most effective tools to managing this chronic disease (e.g. medications, surgery) are not available to those of us involved in pediatric obesity management.
Thus, I certainly do not envy my pediatric colleagues in their struggles to provide meaningful obesity management to their young clients.
I am not sure how my somewhat sobering talk will be received by this public health audience, but then again, I don’t think I was expected to fully toe the line when it comes to exclusively focussing on nutrition and activity (as important as these factors may be) as an effective way to prevent or even manage childhood obesity.
Wow, what a week!
Just back from the 5th Canadian Obesity Summit, there is no doubt that this summit will live long in the minds (and hearts) of the over 500 attendees from across Canada and beyond.
As anyone would have appreciated, the future of obesity research, prevention and practice is alive and kicking in Canada. The over 50 plenary review lectures as well as the over 200 original presentations spanning basic cellular and animal research to health policy and obesity management displayed the gamut and extent of cutting-edge obesity research in Canada.
But, the conference also saw the release of the 2017 Report Card on Access to Obesity Treatment for Adults, which paints a dire picture of treatment access for the over 6,000,000 Canadians living with this chronic disease. The Report Card highlights the virtually non-existant access to multidisciplinary obesity care, medically supervised diets, or prescription drugs for the vast majority of Canadians.
Moreover, the Report Card reveals the shocking inequalities in access to bariatric surgery between provinces. Merely crossing the border from Alberta to Saskatchewan and your chances of bariatric surgery drops from 1 in 300 to 1 in 800 per year (for eligible patients). Sadly, numbers in both provinces are a far cry from access in Quebec (1 in 90), the only province to not get an F in the access to bariatric surgery category.
The presence of patient champions representing the Canadian Obesity Network’s Public Engagement Committee, who bravely told their stories to a spell-bound audience (often moved to tears) at the beginning of each plenary session provided a wake up call to all involved that we are talking about the real lives of real people, who are as deserving of respectful and effective medical care for their chronic disease as Canadians living with any other chronic disease.
Indeed, the clear and virtually unanimous acceptance of obesity as a chronic medical disease at the Summit likely bodes well for Canadians, who can now perhaps hope for better access to obesity care in the foreseeable future.
Thanks again to the Canadian Obesity Network for hosting such a spectacular event (in spectacular settings).
More on some of the topics discussed at the Summit in coming posts.
For an overview of the Summit Program click here
Many diet plans praise the importance of strict adherence to whatever the storyline of the diet happens to be. This includes tips on what foods to avoid or to never eat. Indulging in these “forbidden” foods, is considered cheating and failure.
Now, research by Rita Coelho do Vale and colleagues, published in the Journal of Consumer Psychology, explores the notion that planned “cheats” can substantially improve adherence with restrictive diets.
Using a set of controlled dietary experiments (both simulated and real dieting), the researchers tested the notion that goal deviations (a more scientific term for “cheats”) in the plan helps consumers to regain or even improve self-regulatory resources along the goal-pursuit process and can thus enhance the likelihood that the final goal is attained.
That, is exactly what they found:
Compared to individuals who followed a straight and rigid goal, individuals with planned deviations helped subjects regain self-regulatory resources, helped maintain subjects’ motivation to pursue with regulatory tasks, and (3) has a positive impact on affect experienced, which are all likely to facilitate long-term goal-adherence.
Thus, the authors conclude that, “…it may be beneficial for long-term goal-success to occasionally be bad, as long it is planned.”
This is not really that new to those of us, who recommend or use planned “treats” as a way to make otherwise restrictive diets bearable.
Good to see that there is now some research to support this notion.
Now a paper by James Mitchell and colleagues, published in JAMA Surgery, reports on the postoperative eating behaviors and weight control strategies that are associated with differences in body weight seen at 3 years after bariatric surgery.
The study looks at self-reported data from over 2000 participants in the The Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) study, a multicenter observational cohort study at 10 US hospitals in 6 geographically diverse clinical centers in the USA. Participants completed detailed surveys regarding eating and weight control behaviors prior to surgery and then annually after surgery for 3 years.
The researchers assessed 25 postoperative behaviors related to eating, weight control practices, and the use of alcohol, smoking, and illegal drugs.
The three key behaviours associated with poor outcomes were lack of weekly self-weighing, continuing to eat when feeling full more than once a week, and eating continuously during the day.
Thus, a participant who postoperatively started to self-weigh regularly, stopped eating when feeling full, and stopped eating continuously during the day after surgery would be predicted to lose almost 40% of their baseline weight compared to only 24% weight loss in participants who did not adopt these behaviours.
Other behaviours that had negative influences on outcomes included problematic use of alcohol, smoking and illegal drugs.
Thus, as one may have suspected all along, helping patients adopt and adhere to behavioural changes that include self-montioring and mindful eating behaviours can be expected to substantially affect the success of bariatric surgery.
Seoul, South Korea