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There Is More To Obesity Than Just Energy In and Energy Out

Continuing with citations from my article in Obesity Reviews on an aeteological framework for assess obesity, I have the following quote to offer: In the same manner in which a complete understanding of oedema requires the assessment of the complex physiological systems affecting fluid and sodium homeostasis, understanding obesity requires a comprehensive appreciation of the multitude of factors affecting energy intake and expenditure. Energy expenditure can be further subdivided into non‐activity (= resting metabolic rate + dietary‐induced thermogenesis) and activity thermogenesis (= non‐exercise + exercise activity thermogenesis). For simplicity’s sake, these three elements can be termed diet, metabolism and activity. A change in any one of these elements, if not balanced by corrective changes in the others, will result in a net change in energy balance, which, if positive, will result in caloric ‘retention’ and weight gain. In subsequent posts, I will discuss the many factors that can affect energy metabolism, food intake, and physical activity and how changes to each (if not balance by corrective changes in the others) can lead to weight gain and often pose barriers to obesity management. Stay tuned…. @DrSharma Edmonton, AB

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Obesity Can Be Conceptualized As “Caloric Retention”

Several years ago, my colleague Raj Padwal and I published a paper in Obesity Reviews, where we outline a rational approach to an aetiological assessment of obesity. As many readers may not have seen this paper, I will repost several of the key elements we discussed in it. Although some of our thinking has evolved since then, I believe the overall reasoning remain as relevant today, as when we first wrote the paper back in 2010: Obesity is characterized by the accumulation of excess body fat and can be conceptualized as the physical manifestation of chronic energy excess. Using the analogy of oedema, which is the consequence of positive fluid balance or fluid retention, obesity can be seen as the consequence of positive energy balance or caloric retention. Just as the positive fluid balance of oedema can result from a host of underlying aetiologies including cardiac, hepatic, renal, endocrine, infectious, venous, lymphatic or drug‐related causes, obesity can result from a wide range of aetiologies that promote positive energy balance. As with oedema, assessment and management of obesity requires an exploration of the root causes and underlying pathologies. To extend the obesity–oedema analogy, addressing all forms of obesity simply with caloric restriction and exercise (‘eat less and move more’) would be akin to addressing all forms of oedema simply with fluid restriction and diuretics. As this narrowly focused approach is not considered standard‐of‐care in managing patients with oedema, why should it be considered as the preferred method of treating obesity? The classical treatment of obesity, based on increased physical activity and decreased calorie intake, has not been successful. Approximately two‐thirds of the people who lose weight will regain it within 1 year, and almost all of them within 5 years. In our opinion, the lack of efficiency in these therapeutic approaches is likely due to an incomplete understanding of the precise aetiology or aetiologies of obesity and, consequently a failure to address the root causes of energy imbalance. In this paper, we present a theoretical diagnostic paradigm that provides an aetiological framework for the systematic assessment of obesity and discuss how this framework can enhance our ability to diagnose and manage obesity in clinical practice. The framework considers socio‐cultural, physiological, biomedical, psychological and iatrogenic factors that can determine energy input, metabolism and expenditure. Comment: In hindsight, I would note that apart from failure to address the underlying pathology and drivers of… Read More »

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Do Anti-Depressants Promote Weight Gain?

There is no doubt that some people gain weight when started on anti-depressant medications. However, it is also true that the increased appetite and listlessness that accompanies “atypical” depression can contribute to weight gain. Finally, there is evidence that weight-gain in turn may decrease mood, which in turn may further exacerbate weight gain. Trying to cut through all of this is a study by Rafael Gafoor and colleagues from King’s College London, in a paper published in BMJ. They examined data from the  UK Clinical Practice Research Datalink, 2004-14, which included data on 136,762 men and 157,957 women with three or more records for body mass index (BMI). In the year of study entry, 17,803 (13.0%) men and 35,307 (22.4%) women with a mean age of 51.5 years were prescribed anti-depressants. While during 1, 836,452 person years of follow-up, the incidence of new episodes of ≥5 weight gain in participants not prescribed anti-depressants was 8.1 per 100 person years, it was slightly higher at 11.2 per 100 person years in those prescribed an anti-depressant. In the second year of treatment the number of participants treated with antidepressants for one year for one additional episode of ≥5% weight gain was 27. Thus, there appears to be a slight but discernible increased risk of weight gain associated with the prescription of anti-depressants, which may persist over time and appears highest during the second and third year of treatment. However, as the authors caution, these associations may not be causal, and residual confounding might contribute to overestimation of associations. Nevertheless, the notion that there may be a distinct weight-promoting pharmacological effect of some anti-depressants is supported by the finding that certain anti-depressants (e.g. mirtazapine) carry a far greater risk of weight gain than others (e.g. paroxetine). Given the frequency with which anti-depressants are prescribed, it could be argued that the contribution of anti-depressants to the overall obesity  epidemic (particularly in adults) may be greater than previously appreciated. If nothing else, patients prescribed anti-depressants should be carefully monitored for weight gain and preventive measures may need to be instituted early if weight gain becomes noticeable. @DrSharma Edmonton, AB

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The Vast Majority Of Healthy Women Will Become Unhealthy!

Most healthy women, who live long enough, will eventually become unhealthy. So it should not at all come as a surprise to anyone, that the vast majority of women with “healthy” obesity (a misnomer, as in my view, the medical term “obesity” should only apply to people who already have health problems attributable to abnormal or excess body fat), eventually end up with “unhealthy” obesity. This, essentially, is the gist of a paper by Nathalie Eckel and colleagues, published in The Lancet. In their study of 90,257 participants of the Nurses Health Study, who were followed-up from 1980 to 2010 for incident cardiovascular disease (representing over 2 million person-years of follow-up), they found that around 80% of metabolically healthy women with obesity converted to metabolically unhealthy obesity over the course of follow-up. But one might say that this was only marginally higher that the 70% of metabolically healthy “normal weight” women, who also converted to metabolically unhealthy over the 20 years of observation. In fact, the population-attributable risk of the latter group was much higher, as it consisted of almost 10 times the number of women than in the former. While the risk of cardiovascular disease was statistically elevated (by about 40%) in the metabolically healthy women with obesity, this risk was 243% higher in metabolically unhealthy women with normal weight, 260% higher in metabolically unhealthy women with overweight and 315% higher in metabolically unhealthy women with obesity, all compared to metabolically healthy women with normal weight. So, yes, women with metabolically “healthy obesity” have a high risk of becoming metabolically unhealty and developing cardiovascular disease, so are metabolically healthy normal-weight women. Overall, I believe it is safe to say that the vast majority of metabolically healthy women (regardless of body weight) will eventually become metabolically unhealthy, at which time their risk for cardiovascular disease increases. Bottom line, everyone (not just women with obesity) will benefit from efforts to stay as metabolically healthy as possible for as long as possible – fortunately, we know that healthy diets and regular physical activity (while not necessarily preventing weight gain) can help maintain metabolic health, irrespective of current body weight. Clearly, living as healthy as possible is not just good advice for women with obesity – who would have guessed? @DrSharma Edmonton, AB p.s. although this was a study in women, I have no doubt whatsoever that the findings also apply to men… Read More »

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Are Bariatric Centres of Excellence Meeting The Standards of Care?

Anyone familiar with the issue, would readily agree that the actual surgery involved in bariatric surgery is only a small (but undeniably important) technical piece in what is a rather complex treatment for a rather complex chronic disease. Clearly, this is not exactly how all bariatric surgeons approach or treat their bariatric patients. Since 2012, the US has a Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program that designates bariatric surgery centers as Centres of Excellence if they meet specified requirements in 7 core standards that include case volume, commitment to quality, appropriate use of equipment and instruments, critical care support, continuum of care, data collection, and continuous quality improvement. However, as a recent paper by Andrew Ibrahim and colleagues, published in JAMA Surgery, elaborates, despite these quality criteria, there remains a substantial variability in outcomes across designated Bariatric Centres of Excellence. Based on their retrospective analysis of claims data from 145 527 patients who underwent bariatric procedures, there was a 17-fold variation (ranging from 0.6% to 10.3%) in rates of serious 30-day complications across accredited bariatric centers nationally and up to 9.5-fold variation across individual states. As the authors note, “this finding suggests that participation alone in the Center of Excellence Program did not ensure uniform high-quality care….Given that most bariatric procedures are now performed at accredited centers, wide variation among these centers suggests that accreditation alone does not discriminate enough to guide patients to the best centers for care.” Moreover, they found that poor performing centres were often located close to better performing centres (regression to the mean?). Interestingly, in contrast to what one may suspect, outcomes overall were not related to case volume (perhaps because in order to be a designated Centre of Excellence, all centres needed to have a minimum number of cases per year). Rather, the authors discuss that poorer outcomes may be largely attributable to varying technical skills of the surgeons as well as inconsistent adherence to accepted bariatric care pathways. Finally, the authors argue that there is  need to make performance data available to the public, as simply trusting in the “Centre of Excellence” designation by no means guarantees excellent outcomes. As important as these data may be, it is also important to note that this paper only looked at complications within a 30-day time period following surgery. As anyone dealing with bariatric patients is well aware, successful outcomes of bariatric surgery(as well as its… Read More »

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