Factors That Can Affect Ingestive Behaviour: Psychological or Hedonic Factors

Continuing with citations from my article in Obesity Reviews on an aeteological framework for assessing obesity, we now turn to the some of the factors that can affect ingestive behaviour: Psychological or Hedonic Factors In contrast to hyperphagia resulting from physical hunger, over‐eating for emotional reward or as a coping strategy is regulated by the hedonic system and has little to do with the body’s real or perceived need for calories. The range of psychological or emotional factors that can initiate and influence eating encompass virtually the entire range of emotional responses including stress, frustration, loneliness, anxiety, anger, disgust, fear, grief, joy, relief, all of which can significantly alter dietary restraint or promote disinhibition. Typically, hedonic hyperphagia is associated with the selection and consumption of highly palatable energy‐dense ‘comfort’ foods, although homeostatic hyperphagia also tends to be associated with the preferential consumption of palatable foods. In addition to simple ‘emotional’ over‐eating, specific psychiatric conditions that affect food intake or can pose important barriers to maintaining a healthy diet must be considered. Increased appetite is a feature of atypical depression and can be interpreted as ‘self‐medicating’ with food – particularly in cases where these foods affect the serotonergic and reward systems to improve mood. Binge eating, night eating and other abnormal eating behaviours must also be seen in the context of underlying emotional or psychological processes that are distinct from homeostatic ingestive behaviour. Other mental health conditions that can significantly affect eating include attention deficit disorders, post‐traumatic stress syndrome, sleep disorders, chronic pain, anxiety disorders, addictions, seasonal affective disorder and cognitive disorders. Particularly sleep deprivation has been associated with increased appetite and ingestion of highly palatable snacks as well as increased risk for diabetes. Patients with obesity resulting from emotional eating or hedonic hyperphagia are most likely to benefit more from psychological and/or psychiatric interventions rather than simply from dietary counselling. Commentary: Although for didactic and practical purposes I find it helpful to distinguish between what I have referred to as “homeostatic” vs. “hedonic” hyperphagia, it is important to note that at a physiological level, the distinction between the “homeostatic” and “hedonic” pathways is not as clear cut as is often assumed. In fact, there is close and complex cross talk between these pathways. For example, hunger, a feature of the “homeostatic” pathway, is also a powerful activator of the “hedonic” pathway, thus leading to seeking out and consumption of caloric-dense… Read More »

Residential Schools And Indigenous Obesity – More Than Just Hunger?

A recent CMAJ article, by Ian Mosby and Tracey Galloway from the University of Toronto argues that one of the key reasons why we see obesity and diabetes so rampant in Canada’s indigenous populations, is the fact that widespread and persistent exposure to hunger during the notorious residential school system may have metabolically “programmed” who generations toward a greater propensity for obesity and type 2 diabetes. There is indeed a very plausible biological hypothesis for this, “Hunger itself has profound consequences for childhood development. Children experiencing hunger have an activated hypothalamic–pituitary–adrenal stress response. This causes increased cortisol secretion which, over the long term, blunts insulin response, inhibits the function of insulin-like growth factor and produces long-term changes in lipid metabolism. Through this process, the child’s physiology is essentially “programmed” by hunger to continue the cycle of worsening effects, with their bodies displaying a rapid tendency for fat-mass accumulation when nutritional resources become available.” While the impact of hunger may well have been one of the key drivers or metabolic changes, the authors failed to acknowledge another (even more?) important consequence of residential schools – the impact on mental health. Oddly enough, in a blog post I wrote back in 2008, I discussed the notion that the significant (and widespread) physical, emotional, and sexual abuse experienced by the generations of indigenous kids exposed to the residential school system would readily explain much of the rampant psychological problems (addictions, depression, PTSD, etc.) present in the indigenous populations across Canada today. The following is an excerpt from this previous post: This disastrous and cruel [residential school] policy resulted in much pain and despair in the First Nations’, Inuit and Metis people that lasts to this day (known as the “generational effect”). Sexual, physical and mental abuse was widespread; students were broken in heart and spirit; culture and identities were destroyed. Much (if not all) of what ails the Aboriginal peoples of Canada can be traced back to this policy – including possibly issues that affect Aboriginal health to this day. It is no secret that obesity and its consequences (e.g. diabetes) are rampant amongst the Aboriginal peoples of Canada. While poverty, breakdown of traditional lifestyle and culture and even genetic factors (thrifty genotype) have all been implicated in this, I wonder how much the misery caused by the residential school program had to contribute. Early traumatic life experiences including sexual, mental and physical… Read More »

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 »

Arguments Against Obesity As A Disease #6: Stigmatizes People Living With Obesity

Continuing in my miniseries on arguments I often hear against calling obesity a disease, I will now deal with the issue of stigma and discrimination, namely that declaring obesity a disease stigmatizes people who may be healthy. I have already dealt with the issue of not using the terms “obesity” to describe people of size, who are perfectly healthy. Thus, using the actual WHO definition of obesity (the accumulation of excess or abnormal body fat that impairs health), this term should not used to describe people who do not experience health problems from their body fat. That said, how exactly does obesity stigmatize people who actually have obesity (using the above definition and not simply BMI)? No doubt, obesity is a highly stigmatised condition, but so are numerous other diseases including depression, addictions, HIV/AIDS and many others. While much has been achieved in destigmatizing these conditions, obesity still lags far behind. This problem cannot be addressed by refusing to call obesity a disease – it can only be addressed by getting people (including friends and family) to understand the complex and multi-factorial nature of this disorder and the rather limited treatment options that we currently have available for people living with this disease. It is not calling obesity a disease that promotes weight bias and stigma, rather, it is the fairy tale of “choice” and the overly simplistic “eat-less move-more” propaganda that stigmatises people living with excess weight by promoting discriminatory stereotypes and the notion that they are simply not smart or motivated enough to change their slovenly ways. In contrast, acknowledging that obesity is a disease with a complex psychosociobiology, if anything, can actually help move us towards destigmatising obesity in the same way that depression has been destigmatised by reframing the issue as a matter of “chemicals in the brain” (which incidentally would also apply  to most of obesity). Thus, not only should calling obesity a disease help reduce stigma but also hopefully go a long way in reducing wight-based discrimination in everything from access to care to disability legislation. @DrSharma New Orleans, LA

Senate Report: Bold Policies To Reduce the Number of Demented Canadians

According to a report just released by the Canadian Senate, “In the past three to four decades there has been a drastic increase in the proportion of demented Canadians. Statistics Canada data reveals that almost two thirds of Canadian adults are now demented. Sadly, the increase in dementia rates among children is also dangerously high. About 13% of children between the ages of five and 17 are demented while another 20% are somewhat dull. These numbers reflect at least a two-fold increase in the proportion of demented adults and three-fold increase in the proportion of demented children since 1980.” Just replace the word “demented”with the word “obese” in the above paragraph and you will instantly see what is wrong with this report, which happens to in fact be about obesity, and not about Canadians at risk of or living with dementia. Only when speaking about “obesity crisis”, would an official report composed by professional writers on an important medical condition still use the name of the condition as an adjective. Indeed, the use of “people-first language” to describe someone living with a condition rather than being defined by that condition has long been accepted in the case of virtually every other condition. Thus, we speak of people living with addictions rather than of addicts, of people living with diabetes rather than of diabetics, of people living with psychosis rather than of psychotics, of people with arthritis rather than of arthritics, of people living with cancer rather than of the cancerous, you get my drift. Enough has been written on this issue here, here, here, here, here and here. A report that wants to be taken seriously as addressing the concerns and struggles of Canadian adults and children living with overweight or obesity could perhaps begin by ensuring that it uses the proper language. This is not to say that the report does not indeed make bold and important policy recommendations – it does, from taxing sugar-sweetened beverages to limiting advertising to children, to rewriting Canada’a Food Guide to food labeling to tax benefits to promote physical activity (and more). It even addresses (although in passing) the need to provide better treatments to people living with overweight or obesity. Just which of these policy recommendations will actually find their way into legislation and how much difference they’ll actually make remains to be seen especially as the recommendations come with no actual funding… Read More »