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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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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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

 

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Tuesday, August 19, 2014

Can a Non-Profit Urban Food Initiative Alleviate Food Insecurity?

Doug Rauch, former President of Trader Joe's

Doug Rauch, former President of Trader Joe’s

Healthy eating (especially produce) is well out of reach for many who have hungry mouths to feed (despite ivory tower experts who proclaim that you can eat healthy for under $2 a day if you only follow their “tips”).

As food insecurity is certainly one of the key drivers of obesity especially within the lower socioeconomic strata, I was very interested in a paper by Deepak Palakshappa and colleagues, who describe a non-profit initiative to address food insecurity, in a paper published in JAMA Pediatrics.

This initiative, that has yet to open its first store, is to be launched by Doug Rauch, former president of Trader Joe’s grocery chain, who believes that nonprofit supermarkets in low-income neighborhoods can help provide nutritious low-cost foods by selling food gathered from the fresh produce and perishables that are discarded from other supermarkets. (The first store, named the Daily Table, has been proposed to open in Dorchester, a low-income neighborhood in Boston, Massachusetts.)

Indeed, there is an incredible amount of food that goes waste because it either does not meet the high standards of appearance of supermarket chains or is close to or past its “best-before” date.

As the authors point out,

“While most people believe these dates are based on safety, manufacturers and retailers focus on a product’s shelf life, which is based on peak freshness, which is a function of how the food looks and smells. Many manufacturers date their products earlier because of concerns about protecting their brand image. The US Department of Agriculture states the labels are not safety dates and if food is handled and stored properly, it should be safe to consume even if it is past the date. The confusion specifically regarding date labeling is estimated to lead to 32 billion pounds of avoidable food waste a year.”

The paper also discusses whether such an approach would be deemed ethical. As the authors are quick to point out, the first store has yet to be opened so exactly how things will play out in real life awaits to be seen. 

However, there are good reasons to assume that this initiative has the potential to increase the consumption of fruits and vegetables and offers option of purchasing low-cost healthy foods rather than mandating their consumption of healthy foods. The location of these stores in low-income neighbourhoods should help addresses the disparity in access to healthy foods by providing a convenient place for individuals who otherwise may not have healthy foods readily available.

The stores will also offer cooking and health eating classes to promote the autonomy of clients to determine with items to purchase.

The authors also hope that this approach, rather than blaming the individual, will provide an environment conducive to healthier eating while also respecting local social and cultural values.

Of course, whether all of this will work and whether or not such an initiative can be economically viable in the long term remains to be seen. Nevertheless, the initiators of this idea should at least be commended on giving this a shot.

@DrSharma
Edmonton, AB 

Hat tip to Geoff and Ximena for bringing this article to my attention

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Monday, August 18, 2014

Hormonal Responses to Food Intake Begin in Your Mouth

ChewOnThisLogoIn my current show at the 33rd Edmonton International Fringe Theatre Festival, I joke about the importance of chewing your food. This has classically been noted to be of importance to allow the enzymes in saliva to begin the process of digestion.

However, now a fascinating study by Yong Zhu and colleagues from Iowa State University, published in Physiology and Behaviour shows that chewing prompts hormonal changes that vary based on the composition of the food.

In their study, ten healthy males volunteers underwent a sham-feeding experiments (you chew but do not swallow your food) after an overnight fast with 3-min chewing of water, high-fat (nuts), high-carbohydrate (cereal) or high-protein (cheese) food provided in a randomized order (on four separate occasions).

While plasma glucose levels increased slightly and plasma lipids decreased slightly after all test foods, the high-carbohydrate food elicited significantly higher insulin, and the high-protein food resulted in higher ghrelin compared to other test sessions.

The authors attribute these changes in part to neuronal signals transmitted through the vagal nerve, which can for e.g. stimulate glucagon release, thereby explaining the observed increase in plasma glucose levels after all foods.

This study shows that short-term oral exposure to different foods can result in metabolic and hormonal changes that are partly dependent on diet composition.

If nothing else, this study points to the fact that chewing is not simply about mechanically preparing food for swallowing – it is far more a process that puts the organism into a nutritive state with distinct metabolic and hormonal changes.

Chew your food!

@DrSharma
Edmonton, AB

ResearchBlogging.orgZhu Y, Hsu WH, & Hollis JH (2014). Modified sham feeding of foods with different macronutrient compositions differentially influences cephalic change of insulin, ghrelin, and NMR-based metabolomic profiles. Physiology & behavior, 135, 135-42 PMID: 24952264

 

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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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