Dr. Sharma's Obesity Notes » blog

Obesity Weekend Roundup, May 17, 2013

Arya M. Sharma, MD — Sun, 19 May 2013 13:00:10 +0000

As not everyone may have a chance during the week to read every post, here’s a roundup of last week’s posts:

Have a great Sunday! (or what is left of it)

AMS
Frankfurt, Germany

Obesity & Energetic Offerings, May 17, 2013

Arya M. Sharma, MD — Sat, 18 May 2013 13:00:52 +0000

David Allison, PhD, Distinguished Professor, University of Alabama

For several months now, my colleagues at the University of Alabama have been compiling a weekly list of selected obesity related articles in a list they call Obesity and Energetic Offerings.

The list is compiled by David B. Allison, Michelle Bohan-Brown, Emily Dhurandhar, Kathryn Kaiser, and Andrew Brown.

The following is a selection of articles from this week’s list that caught my attention – - the link headings are theirs, not mine:

Findings Contrary to Hypotheses or Popular Ideas

Aging

Basic Science

Clinical

Commentary

Dietary Fat

Food

Gut Microbiota

Methods

Neighborhoods

Physical Activity

Policy Related

Psychology

Research Reproducibility and Integrity

Salt

Stigma

Sugar, SSBs, and related

Surgery

For a complete list and to directly join this list, please click here.

AMS
Edmonton, Alberta

Prohibition Drives Fast Food Underground?

Arya M. Sharma, MD — Fri, 17 May 2013 13:00:03 +0000

Not quite, although this does make for a good headline.

The actual story, which accompanies the global media reports of the underground smuggling operation that illegally routes KFC contraband to Gaza, however does illustrate the lengths to which people will go to obtain their crunchy fat, salt and sugar fix.

The report in the International Herald Tribune describes the distance KFC has to travel as,

“…a journey that involved two taxis, an international border, a smuggling tunnel and a young entrepreneur coordinating it all from a small shop here called Yamama — Arabic for pigeon.”

According to this report, the entrepreneur, a Mr. Efrangi (aka “the Kentucky guy”),

“..has coordinated four deliveries totaling about 100 meals, making about $6 per meal in profit. He promotes the service on Yamama’s Facebook page, and whenever there is a critical mass of orders — usually 30 — he starts a complicated process of telephone calls, wire transfers and coordination with the Hamas government to get the chicken from there to here.”

While the report focuses on the “resilience” of the Gaza inhabitants, who are merely seeking to live a “normal life”, the story does speak to the lengths that people will go still their “cravings”.

While Mr. Efrangi, for logistical reasons, limits his orders to chicken pieces, fries, coleslaw and apple pie, he may not be in business for long.

As the Tribune reports,

“A Gaza businessman who asked to be identified only by his nickname, Abu Ali, to avoid tipping off his competitors, said he applied for a franchise from KFC’s Middle East dealer, Americana Group, two months ago. Adeeb al-Bakri, who owns four KFC and Pizza Hut franchises in the West Bank, said he had been authorized to open a restaurant in Gaza and was working out the details.”

Throughout human history, people have desired what is most difficult to get – bans and prohibitions have always made stuff more worth having than before (whilst upping the “cool-factor”) – apparently, junk food is no exception.

As an interesting side note, which perhaps speaks to the “addictiveness” of the KFC formula, some readers may recall that KFC (now belonging to PepsiCo) was at one time owned by R.J. Reynolds (now RJR Nabisco) – the makers of Camel, Pall Mall, Winston and other “choice tobacco products”.

AMS
Edmonton, AB

Restoring Energy Balance in Communities

Arya M. Sharma, MD — Thu, 16 May 2013 13:00:24 +0000

Professor Shiriki Kumanyika, University of Pennsylvania, Philadelphia

Based on the simplistic notion that excessive weight gain is merely a matter of calories-in and calories-out, conventional individual-level approaches to obesity have long focussed on restoring energy balance in individuals by attempting to influence energy intake and output (with rather modest success).

What affects weight gain in individuals, may well also influence weight gain in populations, at least that is the underpinning idea of the ecological approach to addressing obesity. But, as in individuals, interventions based on this notion are far from straightforward to implement or sustain.

This may well be, because, as at the individual level, complex sociocultural and psychological (not to mention biological) factors tend to occur that serve to push the energy balance towards the positive side of the equation – this is particularly true for minority and marginalised populations.

Thus, as presented by Shiriki Kumanyika from the University of Pennsylvania at the 20th European Congress on Obesity in Liverpool, social inequalities can make certain population seqments particularly vulnerable for obesogenic factors.

In this context, she emphasised that the term “vulnerability” itself can be discriminating and should be clearly defined in the context of social inequalities that face certain population groups (e.g. ethnic minorities) rather than in terms of “deficits”.

In her talk, she presented an overview of her work demonstrating the markedly increased obesity rates in black women, American Indians and Mexican Americans in the US. As she noted, even in the context of clinical trials, not only do participants from these groups show less weight loss with interventions but also gain weight more rapidly when randomised to the control group.

While the nature of foods and activity options available to whose with limited resources accounts for some of the increased risk, it turns out that higher income does not appear to be protective early in the nutrition-economic transition. Rather, during this transition phase, upward mobility may actually further increase the risk of obesity as behavioural risks (increased caloric intake, sedentariness) become more “affordable”.

In order to better understand these patterns of differences in ethnic minorities, a network consisting largely of black American researchers, has developed a “Community Energy Balance” framework.

At the community level energy balance is mediated through the many factors that directly or indirectly affect food intake and physical activity.

This framework leads to the identification of a wide range of potential intervention targets at the levels of the community, family and individuals.

Other elements of this framework also consider cultural-contextual influences that influence obesity including historical experiences and adaptations, type of minority status, structural influences, and sociocultural influences.

The hope is that although both socio-economic status and ethnic differentials are important, this framework will facilitate a systematic analysis and identification of possible solutions to the inequalities that affect these minority populations.

However, whether or not such interventions will prove more effective in communities than current individual-based interventions clearly remains to be seen. Knowing the intrinsic property of complex systems (including communities) to often respond and adapt in unpredictable ways, often with unintended consequences, it is by no means clear as to which community based approaches to addressing inequalities or other drivers of obesity will ultimately tip populations towards the negative side of the energy balance equation.

AMS
London, UK

Developments in Obesity Treatment Session, ECO 2013

Arya M. Sharma, MD — Wed, 15 May 2013 13:00:05 +0000

This morning, on the last day of the 20th European Congress on Obesity in Liverpool, I attended a session that looked at clinical outcomes in obesity management.

The first talk, given by Karlson from Norway looked at predictors of weight-loss outcomes in about 200 individuals undergoing a program that included several week-long in-patient stays at a rehabilitation centre over the course of a year with follow-up “maintenance” provider-patient contacts. Although the average weight loss at 12 months was only around 10 Kg, the variability in weight-loss response increased, with a substantial number of patients achieving weight loss comparable with bariatric surgery, while others regained much of the initial weight loss. In their analyses, initial weight loss, type 2 diabetes, mental health related quality of life, younger age and employment status were the strongest predictors of success. The other variable that influenced outcomes appeared to be the frequency of visits to the patients’ family doctors.

This was followed by a presentation by Nick Finer (London, UK), who reviewed the improvements in blood pressure in patients treated with the combination of phentermine and extended-release topiramate (marketed by Vivus Pharmacetuicals in the US as Qsymia®) in the CONQUER trial, a 56-week double blind placebo-controlled RCT. Overall, treated individuals experienced approximately 7 mmHg average fall in systolic blood pressure that was sustained over the year of treatment. Irrespective of hypertension status about a third of treated patients achieved a rather impressive greater than 15% weight loss. Not surprisingly, those who lost the most weight, experienced the greatest reduction in blood pressure (-10/-6 mmHg), despite reduction in blood pressure medications in a substantial number of hypertensive patients. Thus, there is no doubt that treatment with PT/TPM combination can result in substantial improvement in blood pressure control, that appear directly related to the degree of weight loss.

Ed Hendricks (US) addressed the issue of whether or not phentermine is actually addictive, a notion that is largely based on similarities in molecular structure of phentermine with amphetamines. Based on a prospective observation of 72 patients treated with rather high doses of phentermine (50+ mg/d) for at least 12 months, who agreed to discontinue their phentermine for 48 hours, there was no evidence for “withdrawal” based on a modified Amphetamine Withdrawal Questionnaire, with the exception of recurrence of hunger (as one might expect). Thus, these findings do not support the notion that abrupt discontinuation following the long-term use of phentermine results in phentermine “dependency” or “addiction”.

William Shanahan, Chief Medical Officer of Arena Pharmaceuticals talked about how treatment with lorcaserin, which will become available for obesity treatment in the US in June (Belviq®), results in a significant decrease in Framingham general cardiovascular risk scores, especially in men. Again, the greatest reduction in risk scores were seen in the patients with the greatest degree of weight loss response on lorcaserin.

Kyra Sim, from the University of Sydney, Australia, described substantial cost savings of obesity treatment in women seeking fertility treatments. This prospective randomised controlled trial included 49 women willing to undergo a three-month weight-loss intervention program using VLCD for 6 weeks followed by a moderately calorie-deficit diet and exercise recommendations. Mean weight loss in the intervention group was about 7%. Fertility rates were 48% in the intervention group vs 18% in the control group – in addition, the cost of each live baby in the intervention group was about one-third in that of the control group.

Marina Reeves, from the University of Queensland, Australia, discussed the issue of substantial weight gain commonly seen in women who survive breast cancer (fortunately, an increasing proportion of women with BC). 90 women with a 1st diagnosis of stage 1-111 breast cancer were enrolled in either a behavioural intervention that involved telephone counselling aiming for a 5-10% weight loss or a usual care group. At 6 months, women in the intervention group (which had a 20% drop out rate), lost about 5% of body weight and showed some increase in moderate to vigorous physical activity, and improvements in fatigue. Overall these findings speak to the feasibility of conducting a larger prospective study to examine the impact of this intervention on longer-term outcomes in breast cancer survivors.

AMS
Liverpool, UK

Disclaimer: I have previously received honoraria for consulting from both Arena and Vivus

Nudge, Nudge – Wink, Wink: Changing Health Behaviours

Arya M. Sharma, MD — Tue, 14 May 2013 13:00:45 +0000

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

Follow live tweets from this conference with #ECO2013

Skeletal Muscle as an Endocrine Organ

Arya M. Sharma, MD — Mon, 13 May 2013 13:00:46 +0000

Prof. Bente Klarlund Pedersen, University of Copenhagen

This week, I am attending the 20th European Congress on Obesity in Liverpool.

The opening plenary lecture this morning was presented by Bente Pedersen from the University of Copenhagen, who reviewed her work demonstrating that the profound positive effects of exercise on metabolism, inflammation, mood and cognitive function are mediated by 100s of proteins secreted from skeletal muscle cells in response to muscle contraction.

These molecules are now referred to as “myokines” and have been shown to exert either autocrine, paracrine or endocrine effects on other organs like adipose tissue, liver, pancreas, bones and brain..

This exciting area of research is nicely summarized in a recent paper by Bente Pedersen and Mark Febbraio published in Nature Endocrine Reviews.

For example, exercise-induced increases in myocellular production of BDNF and IL-6 can increase AMPK-mediated fat oxidation, whereby IL-6 appears to have systemic effects on the liver, adipose tissue and the immune system and even mediates crosstalk between intestinal L cells and pancreatic islets.

Other myokines (e.g. the osteogenic factors IGF-1 and FGF-2; FSTL-1) can improve the endothelial function of the vascular system.

More recently, the myokine irisin, has been shown to promote “browning” of adipose tissue.

Other lines of research suggest that myokines can influence the growth of cancer cells as well as modulate immune function, bone development and pancreatic B-cells.

Current research using proteomic techniques will likely provide further insights into the hundreds of molecules secreted from skeletal muscle in response to physical activity and explain how these myokines mediate the wide-ranging beneficial effects of exercise and the detrimental effects of sedentariness on many chronic diseases.

AMS

Liverpool, UK

You can follow live tweets from the conference at #ECO2013

Obesity Weekend Roundup, May 10, 2013

Arya M. Sharma, MD — Sun, 12 May 2013 13:00:09 +0000

As not everyone may have a chance during the week to read every post, here’s a roundup of last week’s posts:

Have a great Sunday! (or what is left of it)

AMS
Liverpool, UK

Obesity & Energetic Offerings, May 10, 2013

Arya M. Sharma, MD — Sat, 11 May 2013 13:00:29 +0000

David Allison, PhD, Distinguished Professor, University of Alabama

For several months now, my colleagues at the University of Alabama have been compiling a weekly list of selected obesity related articles in a list they call Obesity and Energetic Offerings.

The list is compiled by David B. Allison, Michelle Bohan-Brown, Emily Dhurandhar, Kathryn Kaiser, and Andrew Brown.

The following is a selection of articles from this week’s list that caught my attention – - the link headings are theirs, not mine:

Findings Contrary to Hypotheses or Popular Ideas

Surgery

Sugar-Related

Stigma

Schools/Community

Psychology

Policy Related

Methods

Gut Microbiota

Genetics

Food

Exercise

Epidemiology

Evolution, Ecology, & Energetics

Drugs

Clinical

Body Composition

Basic

For a complete list and to directly join this list, please click here.

AMS
Toronto, Ontario

How Gut Bugs Affect Metabolism

Arya M. Sharma, MD — Fri, 10 May 2013 13:00:14 +0000

Regular readers will be well aware of the increasing evidence that the intestinal bacterial flora may well be an important player in the development of obesity.

Novel insights into exactly how gut bugs may influence metabolism come from a study by Kimura and colleagues from Kyoto University published in Nature Communications.

In their studies in mice, they demonstrated that metabolic effects of gut bugs may be mediated by the production of short-chain fatty acids, which in turn affect energy homeostasis by interacting with the GPR43 receptor in adipose tissue, the activation of which suppresses insulin signalling and fat accumulation in adipose tissue.

Thus, they demonstrated that mice lacking the GPR43 receptor gain weight on a normal diet, while animals overexpressing this receptor appear obesity resistant even when fed a high-fat diet.

Support for the role of gut bugs comes from the fact that mice held in germ-free environments or treated with antibiotics appear completely ‘normal’.

As the authors note,

“These findings establish GPR43 as a sensor for excessive dietary energy, thereby controlling body energy utilization while maintaining metabolic homoeostasis.”

Clearly with regard to the role of gut bugs in obesity – the plot thickens.

AMS
Alliston, ON

Kimura I, Ozawa K, Inoue D, Imamura T, Kimura K, Maeda T, Terasawa K, Kashihara D, Hirano K, Tani T, Takahashi T, Miyauchi S, Shioi G, Inoue H, & Tsujimoto G (2013). The gut microbiota suppresses insulin-mediated fat accumulation via the short-chain fatty acid receptor GPR43. Nature communications, 4 PMID: 23652017