Arguments For Calling Obesity A Disease #8: Can Reduce Stigma

Next, in this miniseries on arguments for and against calling obesity a disease, I turn to the issue of stigma. One of the biggest arguments against calling obesity, is the fear that doing so can increase stigma against people living with obesity. This is nonsense, because I do not think it is at all possible for anything to make stigma and the discrimination of people living with obesity worse than it already is. If anything, calling obesity a disease (defined as excess or abnormal body fat that impairs your health), could well serve to reduce that stigma by changing the narrative around obesity. The current narrative sees obesity largely as a matter of personal choice involving poor will power to control your diet and unwillingness to engage in even a modest amount of regular physical activity. In contrast, the term ‘disease’ conjures up the notion of complex biology including genetics, epigenetics, neurohormonal dysregulation, environmental toxins, mental health issues and other factors including social determinants of health, that many will accept are beyond the simple control of the individual. This is not to say that other diseases do not carry stigma. This has and remains the case for diseases ranging from HIV/AIDS to depression – but, the stigma surrounding these conditions has been vastly reduced by changing the narrative of these illnesses. Today, we are more likely to think of depression (and other mental illnesses) as a problem related to “chemicals in the brain”, than something that people can pull out of with sheer motivation and will power. Perhaps changing the public narrative around obesity, from simply a matter of motivation and will power, to one that invokes the complex sociopsychobiology that really underlies this disorder, will, over time, also help reduce the stigma of obesity. Once we see obesity as something that can affect anyone (it can), for which we have no easy solutions (we don’t), and which often requires medical or surgical treatment (it does) best administered by trained and regulated health professionals (like for other diseases), we can perhaps start destigmatizing this condition and change the climate of shame and blame that people with this disease face everyday. @DrSharma Edmonton, AB

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Arguments For Calling Obesity A Disease #2: It Is Driven By Biology

Continuing in my miniseries on reasons why obesity should be considered a disease, I turn to the idea that obesity is largely driven by biology (in which I include psychology, which is also ultimately biology). This is something people dealing with mental illness discovered a long time ago – depression is “molecules in your brain” – well, so is obesity! Let me explain. Humans throughout evolutionary history, like all living creatures, were faced with a dilemma, namely to deal with wide variations in food availability over time (feast vs. famine). Biologically, this means that they were driven in times of plenty to take up and store as many calories as they could in preparation for bad times – this is how our ancestors survived to this day. While finding and eating food during times of plenty does not require much work or motivation, finding food during times of famine requires us to go to almost any length and risks to find food. This risk-taking behaviour is biologically ensured by tightly linking food intake to the hedonic reward system, which provides the strong intrinsic motivator to put in the work required to find foods and consume them beyond our immediate needs. Indeed, it is this link between food and pleasure that explains why we would go to such lengths to further enhance the reward from food by converting raw ingredients into often complex dishes involving hours of toiling in the kitchen. Human culinary creativity knows no limits – all in the service of enhancing pleasure. Thus, our bodies are perfectly geared towards these activities. When we don’t eat, a complex and powerful neurohormonal response takes over (aka hunger), till the urge becomes overwhelming and forces us to still our appetites by seeking, preparing and consuming foods – the hungrier we get, the more we seek and prepare foods to deliver even greater hedonic reward (fat, sugar, salt, spices). The tight biological link between eating and the reward system also explains why we so often eat in response to emotions – anxiety, depression, boredom, happiness, fear, loneliness, stress, can all make us eat. But eating is also engrained into our social behaviour (again largely driven by biology) – as we bond to our mothers through food, we bond to others through eating. Thus, eating has been part of virtually every celebration and social gathering for as long as anyone can remember. Food is celebration, bonding, culture, and identity – all… Read More »

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Genetic Obesity In Labrador Retrievers

While much has been written on how the current obesity epidemic is not limited to humans but also includes house hold pets and zoo animals, some species appear to be more obesity prone than others. Among dogs, which for centuries have been selectively bred to transform the wild type into all shapes, sizes and temperaments, some breeds likewise appear more prone to weight gain than others – these include labrador retrievers. Now, a study by Eleanor Raffan and colleagues from Cambridge University, UK, in a paper published in Cell Metabolism, have identified a common deletion within the POMC gene that enhances appetite and feeding behaviour. The 14 bp deletion in pro-opiomelanocortin (POMC) with an allele frequency of 12% disrupts the β-MSH and β-endorphin coding sequences and is associated with body weight (mean effect size 1.90 kg per deletion allele, equivalent to 0.33 SDs), adiposity, and greater food motivation. Among another 39 dog breeds, the deletion was only found in the closely related flat-coat retriever (FCR), where it is similarly associated with body weight and food motivation. The influence of this mutation on feeding behaviour is likely complex: “It has been reported that owners of more highly food-motivated dogs make greater efforts to limit their dogs’ access to food. However, there is evidence to suggest dogs are able to influence both the type and quantity of food offered to them by their owners. It is possible that behavior changes related to the mutation are sufficient to lead to increased food intake (either by scavenging or soliciting owner-provided food).” Interestingly, the mutation was found to be significantly more common in Labrador retrievers that had been selected to become assistance dogs than pets suggesting that there may be something about this deletion that positively influences temperament, making them best suited for this kind of work. “Temperament and “trainability” are the main drivers for selection of assistance dogs, and “positive reinforcement” with food reward is a mainstay of puppy training. We therefore hypothesize that dogs carrying the POMC deletion may be more likely to be selected as assistance dogs.” Overall, and this should come as no surprise, these findings show that mutations in the same system that regulates human weight and appetite (and perhaps temperament?) is found in obesity prone canines. Which, incidentally, brings up the issue of selective breeding in humans – but that’s another story. @DrSharma Edmonton, AB  

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Welcome To The International Congress on Obesity, Vancouver 2016

This weekend sees the start of the XIII International Congress on Obesity (ICO), hosted by the World Obesity Federation in partnership with the Canadian Obesity Network (CON) in Vancouver, Canada. As this year’s Congress President, together with World Obesity Federation President Dr. Walmir Coutinho, it will be our pleasure to welcome delegates from around the world to what I am certain will be a most exciting and memorable event in one of the world’s most beautiful and livable cities. The program committee, under the excellent leadership of Dr. Paul Trayhurn, has assembled a broad and stimulating program featuring the latest in obesity research ranging from basic science to prevention and management. I can also attest to the fact that the committed staff both at the World Obesity Federation and the Canadian Obesity Network have put in countless hours to ensure that delegates have a smooth and stimulating conference. The scientific program is divided into six tracks: Track 1: From genes to cells For example: genetics, metagenomics, epigenetics, regulation of mRNA and non–coding RNA, inflammation, lipids, mitochondria and cellular organelles, stem cells, signal transduction, white, brite and brown adipocytes Track 2: From cells to integrative biology For example: neurobiology, appetite and feeding, energy balance, thermogenesis, inflammation and immunity, adipokines, hormones, circadian rhythms, crosstalk, nutrient sensing, signal transduction, tissue plasticity, fetal programming, metabolism, gut microbiome Track 3: Determinants, assessments and consequences For example: assessment and measurement issues, nutrition, physical activity, modifiable risk behaviours, sleep, DoHAD, gut microbiome, Healthy obese, gender differences, biomarkers, body composition, fat distribution, diabetes, cancer, NAFLD, OSA, cardiovascular disease, osteoarthritis, mental health, stigma Track 4: Clinical management For example: diet, exercise, behaviour therapies, psychology, sleep, VLEDs, pharmacotherapy, multidisciplinary therapy, bariatric surgery, new devices, e-technology, biomarkers, cost effectiveness, health services delivery, equity, personalised medicine Track 5: Populations and population health For example: equity, pre natal and early nutrition, epidemiology, inequalities, marketing, workplace, school, role of industry, social determinants, population assessments, regional and ethnic differences, built environment, food environment, economics Track 6: Actions, interventions and policies For example: health promotion, primary prevention, interventions in different settings, health systems and services, e-technology, marketing, economics (pricing, taxation, distribution, subsidy), environmental issues, government actions, stakeholder and industry issues, ethical issues I look forward to welcoming my friends and colleagues from around the world to what will be a very busy couple of days. For more information on the International Congress on Obesity click here For more information on… Read More »

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In-Bred Obesity Resistance Can Be Cancelled Out By Perinatal High-Fat Diet

The periods of early development both in utero and shortly after birth appear to be critical periods for epigenetic programming of lifelong obesity risk. This is once again demonstrated in a fascinating series of experiments by Stefano Guidotti and colleagues from the University of Groningen, The Netherlands, in a paper published in Physiology and Behaviour. The researchers performed their experiments in mice that were selectively bred over 50 generations to voluntarily spend hours in running wheels. Interestingly, the female “runner” mice remain resistant to becoming obese as adults when exposed to a high-fat diet even when they don’t have access to a running wheel. Thus, these mice are resistant to developing obesity whether they run or just sit around. What the researchers now show is that this “resistance” to gaining excess weight (bred over generations) can be fully cancelled out simply by exposing the mice to a high-fat diet for a couple of days shortly after birth. With this exposure, these mice (and even their offspring) are suddenly no longer resistant to weight gain later in life and in fact gain as much weight on high-calories diets as normal mice. Even more interestingly, the short term perinatal exposure to the high-energy diet does not cancel out their love for running. When given a wheel, they continue running just as much as before but even this no longer prevents them from gaining weight. Thus it appears that exposure to a high-energy diet during the perinatal period can have profound effects on the risk of developing adult obesity even in animals bred to be obesity resistant – and, the love for running, does not appear to protect against weight gain. Or, as the authors put it, “..resistance to high-energy diet-induce obesity in adult female mice from lines selectively bred over ~ 50 generations for increased wheel running behavior was blocked by additional perinatal high-energy diet exposure in only one cycle of breeding. An explanation for this effect is that potential allelic variants underlying the trait of diet-induced obesity proneness were not eliminated but rather silenced by the selection protocol, and switched on again by perinatal high-energy diet exposure by epigenetic mechanisms” Moreover, this effect of perinatal high-energy diet exposure and its “reversal effect” on obesity resistance can be passed on to the next generation. Reason enough to wonder just how much the rather dramatic changes in perinatal feeding of infants over the last few decades may be contributing to… Read More »

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