Thursday, September 18, 2014

Efficacy of Vagal Blockade For Obesity Treatment Remains Vague

VBLOC

VBLOC

Regular readers may recall past posts on the use of intermittent electrical blockade of the vagus nerves (VBLOC) as a means of reducing food intake to promote weight loss.

Now a large randomised controlled study of vagal blocakade, published by Sayeed Ikramuddin and colleagues, published in JAMA, reports on rather disappointing outcomes with this treatment.

In this study (ReCharge), conducted  at one of 10 sites in the United States and Australia between May and December 2011, 239 participants with a BMI greater than 40 (or greater than 35 with at least one comorbidity), were randomised to receiving an active vagal nerve block device (EnteroMedics’ Maestro® Rechargeable (RC) System, n=162) or a sham device (n=77).

Over the 12-month blinded portion of the 5-year study (completed in January 2013), the vagal nerve block group lost about 9% or their initial body weight compared to only 6% in the sham group.

In addition to this rather modest difference in weight loss between the groups (about 3%), participants in the active treatment group also experienced a number of clinically relevant adverse effects (heartburn or dyspepsia and abdominal pain).

Thus, overall these rather disappointing results are in line with the previously disappointing observations in the smaller MAESTRO trial.

Based on these findings, it seems that intermittent electrical blockade of the vagal nerve may not hold its promise of a safe and effective long-term treatment for severe obesity after all.

@DrSharma
Edmonton, AB

ResearchBlogging.orgIkramuddin S, Blackstone RP, Brancatisano A, Toouli J, Shah SN, Wolfe BM, Fujioka K, Maher JW, Swain J, Que FG, Morton JM, Leslie DB, Brancatisano R, Kow L, O’Rourke RW, Deveney C, Takata M, Miller CJ, Knudson MB, Tweden KS, Shikora SA, Sarr MG, & Billington CJ (2014). Effect of reversible intermittent intra-abdominal vagal nerve blockade on morbid obesity: the ReCharge randomized clinical trial. JAMA, 312 (9), 915-22 PMID: 25182100

VN:F [1.9.22_1171]
Rating: 0.0/10 (0 votes cast)
VN:F [1.9.22_1171]
Rating: 0 (from 0 votes)


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 than the weight of the money in your back pocket (a fact that even Dr. Oz had to admit to 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

 

.

VN:F [1.9.22_1171]
Rating: 10.0/10 (2 votes cast)
VN:F [1.9.22_1171]
Rating: +2 (from 2 votes)


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

VN:F [1.9.22_1171]
Rating: 10.0/10 (1 vote cast)
VN:F [1.9.22_1171]
Rating: +1 (from 1 vote)


Friday, August 22, 2014

Do Bite Counters Count Bites?

bite counterWith the current electronic self-montioring craze, it was only a matter of time before someone would try to come up with a device that counts the number of bites it takes you to finish a meal.

The device (Bite Counter), is worn no the wrist of the dominant hand and contains a tri-axial accelerometer that detects an upward, arcing motion from the table to the mouth.

Now a study by Jenna Desendorf and colleagues from the University of Tennessee, tested the accuracy and validity of this device in 15 adults (23–58 years old) while eating a meal consisting of foods/beverages, each consumed with different utensils: meat (knife and fork), side items (fork), soup (spoon), pizza (hands), can of soda (hands), and a smoothie (straw), while being observed them through a one-way mirror and counted the number of bites taken.

As the paper, published in Eating Behaviors reports, the overall accuracy of the device was around 80%. However, this varied substantially between foods: meat (127%), side items (82.6%), soup (60.2%), pizza (87.3%), soda (81.7%), and smoothie (57.7%).

So, while this device may well underestimate the number of bites taken during a mixed meal, the real question is what people will start monitoring next – number of chews? (I joke about this on my show) Saliva flow? Numbers of swallows per bite? Oesophageal transit time?

I can perhaps see some research applications but as a way to help improve your eating?

The company claims that limiting your number of daily bites to 100 will help you lose weight.

I am yet to be convinced.

@DrSharma
Edmonton, AB

ResearchBlogging.orgDesendorf J, Bassett DR Jr, Raynor HA, & Coe DP (2014). Validity of the Bite Counter device in a controlled laboratory setting. Eating behaviors, 15 (3), 502-4 PMID: 25064306

 

.

VN:F [1.9.22_1171]
Rating: 0.0/10 (0 votes cast)
VN:F [1.9.22_1171]
Rating: +1 (from 1 vote)


Friday, June 20, 2014

Your Body Thinks Obesity Is A Disease

sharma-obesity-adipose-tissue-macrophageYesterday, the 4th National Obesity Student Summit (#COSM2014) featured a debate on the issue of whether or not obesity should be considered a disease.

Personally, I am not a friend of such “debates”, as the proponents are forced to take rather one-sided positions that may not reflect their own more balanced and nuanced opinions.

Nevertheless, the four participants in this “structured” debate, Drs. Sharon Kirkpatrick and Samantha Meyer on the “con” team and Drs. John Mielke and Russell Tupling on the “pro” team (all from the University of Waterloo) valiantly defended their assigned positions.

While the arguments on the “con” side suggested that “medicalising” obesity would detract attention from a greater focus prevention while cementing the status quo and feeding into the arms of the medical-industrial complex, the “pro” side argued for better access to treatments (which should not hinder efforts at prevention).

But a most interesting view on this was presented by Tupling, who suggested that we only have to look as far as the body’s own response to excess body fat (specifically visceral fat) to determine whether or not obesity is a disease.

As he pointed out, the body’s own immunological pro-inflammatory response to excess body fat, a generic biological response that the body uses to deal with other “diseases” (whether acute or chronic) should establish that the body clearly views this condition as a disease.

Of course, as readers are well aware, this may not always be the case – in fact, the state of “healthy obesity” is characterized by this lack of immunological response both locally within the fat tissue as well as systemically.

Obviously, it will be of interest to figure out why some bodies respond to obesity as a disease and others don’t – but from this perspective, the vast majority of people with excess weight are in a “diseased” state – at least if you asked their bodies.

While this is a very biological argument for the case – it is indeed a very insightful one: it is not the existence of excess body fat that defines the “disease” rather, how the body responds to this “excess” is what makes you sick.

As readers, are well aware, there are several other arguments (including ethical and utilitarian considerations) that favour the growing consensus on viewing obesity as a disease.

Of course,  calling obesity a disease should not detract us from prevention efforts, but, as I often point out, just because be treat diabetes or cancer as diseases, does not mean that we do not make efforts to prevent them.

If calling obesity a disease increases resources towards better dealing with this problem and helps take away some of the shame and blame – so be it.

@DrSharma
Waterloo, Ontario

VN:F [1.9.22_1171]
Rating: 9.0/10 (4 votes cast)
VN:F [1.9.22_1171]
Rating: +2 (from 2 votes)

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

» More news articles...

Publications

  • Subscribe via Email

    Enter your email address:

    Delivered by FeedBurner




  • Arya Mitra Sharma
  • Disclaimer

    Postings on this blog represent the personal views of Dr. Arya M. Sharma. They are not representative of or endorsed by Alberta Health Services or the Weight Wise Program.
  • Archives

     

  • RSS Weighty Matters

  • Click for related posts

  • Disclaimer

    Medical information and privacy
    Any medical discussion on this page is intended to be of a general nature only. This page is not designed to give specific medical advice. If you have a medical problem you should consult your own physician for advice specific to your own situation.


  • Meta

  • Obesity Links

  • If you have benefitted from the information on this site, please take a minute to donate to its maintenance.

  • Home | News | KOL | Media | Publications | Trainees | About
    Copyright 2008–2014 Dr. Arya Sharma, All rights reserved.
    Blog Widget by LinkWithin