Tuesday, September 2, 2014

Can Weight Loss Supplements Promote Weight Gain?

sharma-obesity-weight-loss-supplementsApart from the fact that there are indeed no weight-loss supplements that will help you lose more weight than the weight of the money in your back pocket (a fact that even Dr. Oz had to admit at a recent senate inquiry into the rubbish he promotes on his shows), there may be reason to suspect that the use of such supplements may in fact do the opposite.

Thus, a rather simple experiment by Yevvon Chang and Wen-Bin Chiou from Tunghai University, Taichung, Taiwan, published in Nutrition, suggests that taking a (supposed) weight-loss supplement may actually lead to greater caloric intake.

This field study was conducted in 70 volunteers, who were randomised to taking a either placebo or a weight-loss supplement (the same placebo) and were then exposed to a buffet meal.

On average, participants presumably taking weight loss supplements ate a greater number of food items than did control subjects (overall about 30% more food). They also tended to chose less healthy items than the control group.

This effect tended to be strongest in those subjects who had a more positive attitude towards taking supplements for weight loss (those with the most positive attitude eating almost 3 times more food items).

Or, as the authors summarise,

“…the results supported our hypothesis that taking weight loss supplements was associated with an inclination to eat more food. This link was driven by perceived progress toward the goal of weight reduction. The liberating effect of taking weight loss supplements on food consumption became more prominent as attitudes toward this kind of supplement became more positive.”

Obviously, it is hard to extrapolate from such a short-term experiment to what happens over time – especially when people do follow the lifestyle recommendations that come with most supplements (eat-less-move-more).

This study certainly is in line with the recent observation that people who take statins to lower their blood cholesterol levels tend to eat unhealthier diets and may in fact end up gaining more weight than people who don’t.

Thus, it may be time to study the “fattening” effect of weight-loss supplements. Perhaps the only reason that we have not yet observed this effect in larger studies is because very few people stay on these nonsensical agents for more than a few weeks.

@DrSharma
Gambach, Germany

ResearchBlogging.orgChang YY, & Chiou WB (2014). The liberating effect of weight loss supplements on dietary control: A field experiment. Nutrition (Burbank, Los Angeles County, Calif.), 30 (9), 1007-10 PMID: 24976417

 

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Monday, September 1, 2014

Guest Post: Emotional Distress And Weight Gain

Erik Hemmiingsson, PhD, Obesity Research Centre, Karolinska Institute, Stockholm, Sweden

Erik Hemmiingsson, PhD, Obesity Research Centre, Karolinska Institute, Stockholm, Sweden

Today’s guest post comes from Erik Hemmingsson, PhD,  a Group Leader at the Obesity Center, Department of Medicine, Karolinska Institute, Stockholm, Sweden. His group studies the role of psychological and emotional distress in weight gain and obesity by mapping life events that influence stress, metabolism and body weight. Erik has a PhD in Exercise and Health Sciences from the University of Bristol (2004) and a PhD in Medicine from Karolinska Institutet.

I work as a researcher in a specialized obesity treatment center at a university hospital in Sweden. My job is to develop new and more effective treatment and prevention methods so that we can hopefully confine obesity to the history books some day.

For many years I mostly did studies on behaviour therapy combined with low energy diets. Since this did not result in any major breakthroughs, I decided to try something a little different.

I had been aware of that many of our patients had experienced difficult childhoods. There were so many sad stories, but I didn’t fancy doing any research on the topic, it was too painful. But then my attitude gradually started to change about a year ago. It was clear that our current treatment methods were woefully ineffective, but I also became more receptive to all those troublesome stories from the patients. Enough was enough, it was time act. So, like Neo in the Matrix movies, I decided to take the red pill, and delve deeper into the very uncomfortable subject of childhood abuse and adult obesity.

I searched the literature and quickly saw that there were more than enough studies for a systematic review and meta-analysis. I enlisted the help of Dr Kari Johansson and Dr Signy Reynisdottir, and got to work.

What we found very much confirmed all those clinical observations, i.e. there was a very robust association between childhood abuse and adult obesity. The association was also very consistent across difference types of abuse, with an increased risk of about 30-40%. There was also a dose-response association, i.e. the more abuse, the greater the risk of obesity.

While this study confirmed something very important, it was also clear that not everyone who suffers childhood abuse develops obesity, or that all obese individuals have suffered childhood abuse, or the effects would have been even more pronounced. But for me, the study proved that stressful childhood experiences can easily manifest as obesity many years later. This led me even deeper down the rabbit hole. I wanted to know why.

I decided to try and piece together different ideas about how obesity develops in relation to stressful life events. This resulted in a new conceptual causal model consisting of six different developmental stages. Like many diseases, obesity development is more likely when there is socioeconomic disadvantage (applies mainly to Europe and North America). Socioeconomic disadvantage can very easily trigger a chain of events that include adult distress, a disharmonious family environment, offspring distress, psychological and emotional overload, and finally disruption of homeostasis through such mechanisms as maladaptive coping responses, stress, mental health problems, reduced metabolism, appetite up-regulation and inflammation.

Much more research is needed to validate the model, but if there is some truth to this theory, which the childhood abuse meta-analysis clearly suggests that there is, then my hope is that we can use this information to develop more effective treatment and prevention methods.

My other hope is that some of the truly horrendous stigma, shame and discrimination that the obese experience can gradually be alleviated, since there is clearly a lot more to obesity etiology than the commonly held preconception that obese individuals are merely lazy and overindulgent.

After having done all this work on obesity etiology, I would say that my top-3 reasons we have an obesity epidemic (in no particular order) are socioeconomic inequality, the junk food invasion, and psychological and emotional distress patterns (usually established at an early age). And when you combine all three you have the perfect storm for weight gain.

You can find more information at my blog at www.holisticobesity.com

Erik Hemmingsson,
Stockholm, Sweden

References:

Hemmingsson E, Johansson K, Reynisdottir S. Effects of childhood abuse on adult obesity: a systematic review and meta-analysis. Obesity Reviews (epub 15 August 2014).

Hemmingsson E. A new model of the role of psychological and emotional distress in promoting obesity: conceptual review with implications for treatment and prevention. Obesity Reviews 2014, 15:769-779.

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Thursday, August 28, 2014

Call For Abstracts: Canadian Obesity Summit, Toronto, April 28-May 2, 2015

COS2015 toronto callBuilding on the resounding success of Kananaskis, Montreal and Vancouver, the biennial Canadian Obesity Summit is now setting its sights on Toronto.

If you have a professional interest in obesity, it’s your #1 destination for learning, sharing and networking with experts from across Canada around the world.

In 2015, the Canadian Obesity Network (CON-RCO) and the Canadian Association of Bariatric Physicians and Surgeons (CABPS) are combining resources to hold their scientific meetings under one roof.

The 4th Canadian Obesity Summit (#COS2015) will provide the latest information on obesity research, prevention and management to scientists, health care practitioners, policy makers, partner organizations and industry stakeholders working to reduce the social, mental and physical burden of obesity on Canadians.

The COS 2015 program will include plenary presentations, original scientific oral and poster presentations, interactive workshops and a large exhibit hall. Most importantly, COS 2015 will provide ample opportunity for networking and knowledge exchange for anyone with a professional interest in this field.

Abstract submission is now open – click here

Key Dates

  • Abstract submission deadline: October 23, 2014
  • Notification of abstract review: January 8, 2014
  • Early registration deadline: March 5, 2015

For exhibitor and sponsorship information – click here

To join the Canadian Obesity Network – click here

I look forward to seeing you in Toronto next year!

@DrSharma
Montreal, QC

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Tuesday, August 26, 2014

Does Facebook Use Promote Eating Disorders?

facebook_button_eu3gSocial media are not just a means of sharing your life with the world – they also open your life to praise (likes and positive comments) or criticism.

Thus, it is easy to see how avid use of such platforms (especially those with ample picture posts) can potentially promote body image and weight obsessions in those who may not be quite confident and happy about their appearance.

That this may not just be an interesting theory is suggested by two studies by Annalise Mabe and colleagues from Florida State University, published in the International Journal of Eating Disorders.

In the first study 960 female college students completed an Eating Attitudes Test that included Dieting and Bulimia/Food Preoccupation subscales with items such as “I eat diet foods” and “I give too much time and thought to food.”

Duration of Facebook use was assessed with the question “How much time do you spend on Facebook per week?” with options ranging from 0 to >7 hours (average used tended to be just over 2 hours per week).

This study found a small but statistically significant positive relationship between the duration of Facebook use and disordered eating.

In the second study, 84 women, who had participated in the first study and endorsed Facebook use on a weekly basis were randomization to either spending 20 mins on their facebook account or finding information about the ocelot on Wikipedia and YouTube.

Participants with greater disordered eating scores endorsed greater importance of receiving comments on their status, and greater importance of receiving “likes” on their status. Those with greater eating pathology reported untagging photos of themselves more often and endorsed comparing their photos to their female friends’ photos more often.

Participants in the control group demonstrated a greater decline in weight/shape preoccupation than did participants who spent 20 min on Facebook. Furthermore post hoc comparisons supported a significant decrease in weight/shape preoccupation in controls.

Facebook use resulted in a preoccupation with weight and shape compared to an internet control condition despite several multivariate adjustments.

As the authors discuss, their finding,

“indicates that typical Facebook use may contribute to maintenance of weight/shape concerns and state anxiety, both of which are established eating disorder risk factors.”

In terms of practical implications of these findings, the authors suggest that,

“Facebook could be targeted as a maintenance factor in prevention programs. For example, interventions could address the implications of appearance-focused comments such as “you look so thin” or “I wish I had your abs,” in perpetuating the thin ideal on Facebook, much as “fat talk” perpetuates this ideal in everyday conversations. An adaption of the “Fat Talk Free” campaign as well as adaptations of media literacy programs could encourage girls and women in the responsible use of social media sites.”

Clearly, this appears to me as a rather fertile area for further research.

I’d certainly be interested in hearing about your experience with facebook and any effects it may have had on your body image or eating behaviours.

@DrSharma
Edmonton, AB

ResearchBlogging.orgMabe AG, Forney KJ, & Keel PK (2014). Do you “like” my photo? Facebook use maintains eating disorder risk. The International journal of eating disorders, 47 (5), 516-23 PMID: 25035882

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Monday, August 25, 2014

How Does Bariatric Surgery Work?

sharma-obesity-gastric_bypass_roux-en-y3Regular readers will be well aware of the fact that bariatric (unfortunately, often referred to as “weight-loss surgery”) is currently the most effective treatment for severe obesity.

However, exactly why and how surgery works remains unclear. Earlier concepts of surgery working either because it creates a mechanical restriction to food intake and/or reduces caloric load due to malabsorption are not borne out by newer studies.

Rather, it seems that complex neurohormonal changes together with often profound changes in ingestive behaviour act together to account for the resulting weight loss (and more importantly) for the long-term weight-loss maintenance.

Just how many factors interact in specific and unspecific ways to lower body weight is now discussed in a review paper by Timothy Sweeney and John Morton, from Stanford University, in a paper published in Clinical Gastroenterology.

As the authors discuss, there is a complex interaction between a wide range of factors including several hormones (leptin, ghrelin, adiponectin, glucagon-like peptide 1 (GLP-1), peptide YY, and glucagon), bile acid changes in the gut and the serum, and changes to the gut microbiome.

The most profound changes in these systems are seen with the roux-en-Y gastric bypass, which induces large and distinctive changes in most measured fat and gut hormones, including early and sustained increase in GLP-1, possible through intestinal bile acid signaling. This may well explain why this operation appears to be the most effective and durable procedure.

Clearly, hope remains that by better understanding the exact mechanisms through which surgery (which will only ever be available to a vanishingly small minority of people with excess weight) works, we will identify mechanisms and targets for desperately needed pharmacological treatments.

@DrSharma
Edmonton, AB

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In The News

Diabetics in most need of bariatric surgery, university study finds

Oct. 18, 2013 – Ottawa Citizen: "Encouraging more men to consider bariatric surgery is also important, since it's the best treatment and can stop diabetic patients from needing insulin, said Dr. Arya Sharma, chair in obesity research and management at the University of Alberta." Read article

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