Dr. Sharma's Obesity Notes

Theresa Marteau, Director Behaviour and Health Research Unit, University of Cambridge

The second morning of the 20th European Congress on Obesity here in Liverpool was kicked off by a presentation by Theresa Marteau, Cambridge Institute of Public Health, on the use of “choice architecture” to “nudge” individuals towards adopting healthier behaviours.

Given the limited effectiveness (some may say “failure”) of attempts to change population behaviours based on conscious, goal directed, reflective interventions, “nudging” attempts to change behaviours through non-conscious, habitual or automatic interventions.

The idea of nudging, defined by Thaler and Sunstein as

“..any aspect of the choice architecture that alters people’s behaviour in a predictable way without forbidding any options or significantly changing their economic incentives”,

is not a new idea to social psychologists and is based on the observation that our conscious processes are finite and that most of our responses to the environment occur below our conscious awareness.

Thus, while previous approaches to changing health behaviours have primarily focussed on conscious cognitive approaches, newer models attempt to change behaviours by targeting the sub-conscious non-reflective processes that underly these behaviours.

In her talk, Marteau described the results of a large-scale scoping review on use of nudging interventions for tobacco-, alcohol-, diet- and physical activity-related behaviours. Her analysis included ~350 articles describing two types of interventions that altered either the properties (ambience, functional design, labelling, presentation, sizing) or placement (availability, proximity) of objects or stimuli within the micro-environent where the behaviour is happening. In addition the analysis looked at priming and prompting interventions.

All of these approaches have in common that they typically require minimal cognitive engagement and can potentially influence many people at the same time. In addition, health nudging, by avoiding the use of literacy and numeracy, may be able to reduce social patterning thus reducing health inequalities.

To date, most of the work on nudging has been done in the context of dietary behaviours, mainly on food labelling and sizing.

As one may expect, studies in experimental settings have shown effects of ambience (e.g. effects of the tempo of music on speed of eating), functional design (e.g. change in packaging), labelling (e.g. use of exciting names or cartoon characters on healthier foods), proximity (e.g. product placement on the shelf), or prompts (e.g signs or announcements) on behaviours.

Thus, for example, ongoing research suggests that simply putting healthier foods at the ends of aisles changes shopper behaviours largely independent of pricing, suggesting that simply changing the placement of foods may be far more effective than changing pricing (e.g. taxation).

The big question, however, is whether these effects are indeed sustained and have large enough effect sizes. So far, the data on this is not clear, which is why Marteau and colleagues are currently working on a synthesis of evidence to see whether such nudging interventions do indeed influence health behaviours outside the laboratory.

In the real world, healthy nudges have to compete with unhealthy nudges – e.g. images or labels warning against overconsumption of fast food have to compete with the strong nudges created by the common association of fast food advertising and images with sporting events – this may well be an insurmountable obstacle given the almost limitless tool box and financial resources of the food industry.

Marteau also addressed the acceptability of nudging interventions. As one may expect, less intrusive interventions such as placing or health prompts were found to be far most acceptable than taxing, pricing, or limiting portion size, which are generally seen as overtly limiting choice.

Ultimately, the issue of acceptability will be the rate-limiting-step for legislators, who need to align public and political wills. This is something that is unlikely to happen without stronger evidence to support broad acceptability of such measures. Countermeasures by industry and the voices of those who oppose coercive paternalism will clearly further limit political enthusiasm for legislative interventions.

On a happier note, Marteau notes that there may be somewhat greater acceptance for choice architecture interventions in children and young people.

Whether or not her optimism is warranted, remains to be seen.

AMS
Liverpool, UK

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Continuing yesterday’s discussion of the paper by Julia Temple Newhook, Deborah Gregory and Laurie Twells from the Memorial University of Newfoundland, St. John’s, published in the Journal of Social, Behavioral, and Health Sciences, on what causes some people to gain weight, we turn to what the authors describe as, “Gradual Processes”.

Thus, in their extensive interviews with individuals seeking bariatric surgery the researchers found a group of patients, who neither started out as overweigh or obese kids but also were unable to identify specific “life events” that would have prompted their weight gain.

Rather, they describe their weight gain as a gradual but incremental process, most commonly attributable to subsequent cycles of “yo-yo dieting” or to a wide range of other factors that affected their eating (emotions, food addictions, cultural habits, irregular eating, or food quality and quantity) or activity behaviours.

The importance of weight cycle was illustrated by,

“As Vanessa, an office worker in her 30s, put it, “As good as I am at losing weight, after 5 or 6 months, I’m even better at finding it.” Elsie, a homemaker in her 50s, said that she had been dealing with this cycle since she was a child: “I remember when I was 8, I was always on a diet. … I think that’s what did it: watching your weight, adding it back on again, back and forth. Each time, you climb higher and higher.”

As for eating behaviour, both quality and quantity were mentioned, albeit not by the same people:

“Zoë, a customer service worker in her 30s, pointed the blame at food quality, referencing her enjoyment of fast food, and said wryly, “I’m 287 pounds. I didn’t get this way from eating soup broth.” In contrast, Elsie said, “I don’t eat a lot of junk anyway, but I guess I just eat too much of the good foods.”

This is in line with what I am always careful to point out – the nutritive quality of a diet has little to do with its caloric quantity. On the other hand, nutritionally poor diets are often also calorically dense, thereby making it far easier to consume excess calories.

While some participants reported emotional eating, this was often in response to “life events” (like losing a spouse), discussed in yesterday’s post. A more insidious form of emotional eating was reported as addiction to certain foods:

“Gladys, a disabled factory worker in her 50s, said, “I’m addicted to candy. I will not bring candy into my house ever again… I’ve gone now almost 2 months. …It’s almost like someone coming off drugs or something. You wean yourself off.” Vanessa said that she felt overwhelmed by her addiction to cheese: “I had a huge, huge, huge cheese addiction. A 500-gram [18-ounce] block of cheese I literally could eat in 2 days. … I feel really controlled by my thoughts for food.”

Cultural overeating was also described:

“Vanessa noted that as a child, “I wasn’t allowed up from the table until I cleaned my plate. … Every celebration is centered around food: potluck, buffet, jiggs dinner, everything. Our culture is really a food culture, and I guess most cultures are.”

Irregular eating patterns including meal skipping was also noted to contribute to weight gain:

“Heidi said, “I can go days without eating and … it doesn’t bother me at all. I can also have days where I’m like, ‘Oh my God, I can’t believe I just ate that—all of that.’ I go from one extreme to the other. … It’s like I never feel full.” Penny, a homemaker in her 30s, described similar experiences: “My biggest problem was never overeating, it was never eating enough. I would get up in the morning and not eat anything until supper time. It never, ever bothered me … I could go days without eating and it wouldn’t bother me.”

Finally in this category of Gradual Processes, the authors describe the issue of lack of physical activity or sedentariness:

“Jennifer said, “It’s the activity level. I work all day, and I’m sat on my butt all day long. I have two kids at home. So the story goes.” In addition, participants explained that once they had gained weight, it was very difficult to move comfortably. This was partially a physical problem, as Brian explained: “You get into a circle because you can’t [exercise] because you have the weight on. You need to do things to get the weight off, but you can’t do it because you got the weight on.”

In addition, once some weight has been gained, emotional factors can further limit physical activity:

“I want to be active. It’s something I’ve always wanted, but I feel [my size] is in the way. It ain’t that I can’t do it, because I can do it; it’s how I’m looked at while I’m doing it. … I can leave here and I can walk [3 miles] and back. I can do it. It’s just that when I’m doing it, it’s the fear I have that everybody is looking at me.”

Once again, all of these stories are quite typical of the many that I have heard before – it is evident that even with gradual progressive weight gain, reasons and interpretations differ widely.

If you have experienced progressive weight gain without this being prompted by any evident “life event”, I’d certainly love to hear from you.

AMS
London, UK

Concluding this brief series on the neurobiology of resilience, based on the paper by Bart Rutten and colleagues from Maastricht University, published in Acta Psychiatrica Scandinavica, I turn my attention to the relevance of these findings for clinicians working in the area of obesity.

Regular readers of these pages, will no doubt be aware of the considerable influence that our thinking patterns and ability to deal with the stressors and adversities of life have on our eating behaviours.

The greater our susceptibility to these stressors and the more “negative” our emotional and cognitive responses, the greater our risk to reach for “comfort” food. No amount of “education” on “healthy eating” will stop this  - as I say in my talks ,  ”You don’t treat alcohol addiction by handing out a drinking plan”.

To summarize the findings from the previous posts:

There is now considerable evidence both from animal and human studies that link resilience to the stress and reward system of the brain.

Early life events, particularly in the area of attachment, trauma (emotional, physical, sexual abuse or even just emotional neglect) or social defeat can result in a sensitized stress system, that leads to an exaggerated stress response in later life. This increased susceptibility appears to be mediated by molecular (i.e. epigenetic) changes in the brain particularly in the genes of the HPA axis and the mesolimbic dopaminergic reward system.

Fortunately, these negative influences can be reduced through positive emotional experiences and finding meaning and a purpose in life. Thus, meditation and spirituality can activate the reward systems in a manner that counteracts the impact of traumatic experiences.

With regard to stress sensitivity, the authors make an important point, namely that increased stress-sensitivity does not preclude experiencing rewards or enjoyment in daily life. In fact, the ability to feel such enjoyment and increased stress-sensitivity appear to be largely independent of each other.

Not only does this speak to the fact that enjoyment and stress-response are mediated by different underlying factors, but it also implies that,

“People can be vulnerable in terms of their tendency to be stress reactive, but also protected from this vulnerability trait in the face of strong tendencies to experience positive emotions in daily life (i.e. from pleasant events or sense of meaning) which buffer stress, prevent future psychopathology and increase mental health.”

“Thus, it seems that the experience of positive emotions has a distinct and more central role in resilience defined as the successful adaptation, swift recovery and psychological growth in the face and recovery phase after exposure to severe adversities, while the stress-response systems appears to mainly mediate vulnerability to stressors.”

Based on the finding that positive emotional experiences and purpose in life are important in counteracting the negative impact of trauma and adverse experiences on resilience, practitioners can recommend and perhaps offer interventions that increase the experience of positive emotions.

These can include meditation and mindfulness techniques not unlike those of religious practices, such as praying, counting one’s blessings and finding oneness with God or humankind.

Other factors such as finding work-life balance, cultivating friendships or hobbies, volunteering for community work, and other forms of positive engagement (even just offering to help your neighbour’s kid with his homework or coaching a baseball team) can perhaps help strengthen resilience thereby reducing the susceptibility not just for mental and physical ailments but for tackling maladaptive eating behaviours – a prerequisite for successful weight management.

AMS
Zurich, Switzerland

Rutten BP, Hammels C, Geschwind N, Menne-Lothmann C, Pishva E, Schruers K, van den Hove D, Kenis G, van Os J, & Wichers M (2013). Resilience in mental health: linking psychological and neurobiological perspectives. Acta psychiatrica Scandinavica PMID: 23488807

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To those, who have been to any of my “Dr. Sharma Shows“, my interest in the topic of resilience should come as no surprise.

If my work with obese clients has taught me anything, it is the simple fact that for those who use food as a coping strategy, the solution will not lie in diet or exercise plans. To them, the discussions for and against sugar-sweetend beverages and the pros or cons of resistance vs. endurance training are irrelevant to a point that makes these discussions almost funny – they seem to exist in a parallel universe.

Indeed, the solution to emotional overeating (including its most severe form namely “binge eating disorder”), can only come from recognizing the relationship between their emotions and their eating behaviours, with the goal to ultimately developing healthier, non-food coping strategies.

Not that these will necessarily lead to weight loss – as I always hasten to point out – eliminating the cause of weight gain does not translate into weight loss – it merely translates into stopping the gain and often, a far better quality of life.

But then again, stopping the gain should be the first step in any weight management program and skipping this step (or fast-forwarding through it), can only guarantee failure.

This is why I firmly believe that for all of us working in the field of obesity, understanding the complex neurobiology of resilience (the successful adaptation and swift recovery after experiencing life adversities), is as essential as understanding the physiology of energy balance.

Readers interested in a rather comprehensive overview of resilience (in the context of mental health) are referred to a paper by Bart Rutten and colleagues from Maastricht University, published in Acta Psychiatrica Scandinavica.

In their extensive and systematic review of the literature, they find that the term “resilience” is used for phenomena ranging from susceptibility to mental health disturbances to adaptation and recovery from adverse experiences.

They describe three possible trajectories that can follow a severe stressor/trauma:

“…ranging from a trajectory showing consistent decline in mental health following exposure to adversity without subsequent recovery of mental health for a prolonged period of time, to a decline in mental health following the exposure that recovers quickly to preexposure levels of mental health and continues to increase thereby surpassing preexposure levels of mental health. This latter response, known as post-traumatic growth, is a very interesting form of adaptation, in which the individual may have obtained a better understanding of his life, possibly from a new perspective, or may have learned to respond efficaciously to similar challenges in the future.”

As the authors point out,

“The neurocircuitries mediating the stress response and reward experience are thought to be crucially involved in the neurobiology of resilience. The efficiency in activating and terminating the response to stress is regulated by elaborate negative feedback systems in the brain and the rest of the body….The hypothalamus–pituitary–adrenal (HPA) axis, the sympathetic nervous system (SNS) and the dopaminergic and serotonergic neurotransmitter systems are major neural systems that govern the stress response..”

There is indeed increasing recognition that experiences profoundly effect brain plasticity:

“These experience-dependent mechanisms regulate the sensitivity and plasticity of the central nervous system and act at several biological levels (likely partly in parallel with each other): i) cellular changes such as neurogenesis, pruning and sprouting of synapses, myelination of axons and alterations to the number of dendritic spines, ii) subcellular changes, such as alterations to the cytoskeleton and the extracellular matrix and changes in the levels of intracellular signalling molecules and iii) molecular (epi) genetic changes such as DNA methylation and chromatin changes. Thus, one can envision that aberrant regulation at any of these levels may moderate risk for and resilience to the consequences of stress and that resilience thus depends on a range of environmental and genetic factors during life.”

Although adverse life experiences can occur and have effects throughout life, there are key times of developmental vulnerability – times, when adverse effects can have “permanent” effects on the individual.

The first period is in early childhood development – beginning right after birth.

In animal studies,

“…parental care during early life induces long-term changes in behaviour as well as in gene expression mediated by epigenetic changes in the hippocampus of rats. As compared with offspring of mother rats with low-nurturing behaviour, offspring of high-nurturing mother rats (displaying more licking and grooming behaviour) were less anxious, had attenuated corticosterone responses after stress exposure and expressed higher levels of the glucocorticoid receptor (GR) in the hippocampus in adulthood. Interestingly, the methylation level of the promoter region of Nr3c1, i.e. the gene encoding the GR, was elevated already the first week of life in the hippocampus of pups that received less and lower quality nurturing , an effect that persisted into adulthood…..other studies have shown that the mother–infant interaction has long-lasting effects on endocrine and behavioural responses later in life.”

“Another interesting line of research has explored the effects of maternal separation on biology and behaviour. Although most studies observed detrimental effects of maternal separation, studies where rat pups were separated from their mother for a very brief period, i.e. 15 min, indicated that these pups, compared with non-separated pups, were more stress resistant later in life. Interestingly, as compared with offspring not separated from their mother for these brief spells in very early life, animals with brief spells of maternal separation showed higher levels of glucocorticoids (GCs) directly after stress exposure in adulthood, with a fast return to basal levels. Thus, type, severity and/or duration of stressful experience early in life seem to influence differential stress reactivity later in life.”

The other vulnerable period appears to be in adolescence, particularly in response to the “social defeat paradigm”,

“In the social defeat paradigm, male test mice aged 6–10 weeks (corresponding to puberty and adolescence in humans) are placed into the territory of a larger and more aggressive resident mouse. The mice are left in this physically and socially stressful situation for approximately 10 min, which leads to subordinate behaviour of the test mouse. After these 10 min, the mice remain in sensory (but not physical contact) with each other for the rest of the day, and the procedure is repeated for 10 consecutive days. The experimental paradigm is known to induce anxiety-like behaviour, prolonged elevations in corticosterone levels and a range of other molecular and cellular changes. Mice that were subjected to chronic social defeat stress furthermore showed a prolonged reduction in orexin signalling in the hypothalamus. Orexin has been implicated in arousal and feeding behaviour, but more recently also in the mesolimbic reward pathway… Although all mice have the same genetic background, and are exposed to similar conditions of social defeat, this experimental paradigm has repeatedly been shown to elicit two distinct responses in the domain of social behaviour: one group of mice displaying social avoidance after the social defeat experience (these mice are called ‘susceptible’), whereas a second group of mice still showing social interaction rates that are comparable with the control group (and is therefore called ‘unsusceptible’ or ‘resilient’). Thus, only a distinct subpopulation (i.e. the ‘susceptible’ mice) displays social avoidance and behavioural signs of anhedonia, while all exposed animals (‘susceptible’ and ‘unsusceptible’ mice) show elevated corticosterone levels and increased anxiety-like behaviour.”

As discussed in the above quote, it is apparent that the molecular changes associated with the response to this stress paragigm are intimately related to the very neurons and areas of the brain known to be linked to eating behaviour. Thus, the impact of adverse life events, whether this is early separation from the mother or exposure to school yard bullying, on eating behaviour and weight trajectories should come as no surprise to anyone working in the field.

Based on their review of the literature, the authors identify three rather consistent predictors of resilience include secure attachment, positive emotional experiences and having a purpose in life.

I will discuss these factors individually in subsequent posts – stay tuned.

AMS
Edmonton, AB

Over the past few days I have shared some of my thoughts on how a “healthy” diet must not only ensure appropriate nutritional and caloric balance but must also foster emotional balance (reasonably skewed to the positive side).

Thinking about this issue, yesterday, I finally got around to picking up the copy of a book on emotional eating that was sent to me several months ago (disclaimer!) by Marcia Sirota, a Toronto-based psychiatrist, who specializes in the treatment of trauma and addictions.

The book with the title, “Emotional Overeating: Know the Triggers, Heal Your Mind, and Never Diet Again“, focusses on the many emotional reasons that drive us to diet and overeat.

To Sirota, dieting and compulsive overeating are simply two sides of the same coin, both rooted in the need to deal with childhood hurts, losses and unmet needs as well as adult suffering, whether conscious or unconscious.

“People think that they don’t have an eating disorder if their weight is normal for their age and body type, but it’s not your size that’s indicative of the problem; it’s the degree to which you think obsessively and behave compulsively with regard to food and your weight. Until you’ve let go of the obsessive thinking and compulsive behaviors associated with disordered eating, you’ll never be happy or free.”

“No matter what your size is, if you can’t stop thinking about eating and weight and can’t stop compulsively indulging or restricting, then you’re unhappily locked in the prison of food addiction.”

The severity of the problem depends on

“…the degree to which you’ve been wounded emotionally and the degree to which food has become the solution to your emotional needs.”

But perhaps, I should allow Sirota to speak for herself in these introductory posts on her blog:

Emotional Overeating Part 1: The Most Overlooked Reason for Why We Overeat

Emotional Overeating Part 2: How to Tell if You’re Doing it

Emotional Overeating Part 3: Be Aware of How You Eat

While clearly, not everyone with excess weight has a story of childhood or adult trauma or loss, I have no doubt that many (not just those, who experience some degree of emotional eating – and who doesn’t?), will benefit from reflections on the emotional aspects of weight and food obsession.

I am still only half way through, so I cannot provide a final opinion on the book and the solution it may provide.

However, I am always happy to see a book on obesity and weight management that does not include recipes or exercise tips – by that standard alone, I would happily recommend this book to anyone interested in a deeper and meaningful analysis of what drives obesity and what doesn’t.

AMS
Edmonton, AB