Monday, March 10, 2014

Will Replacing Vending Machines With Slot Machines Reduce Childhood Obesity?

slot machineIn Western countries, both childhood and adult obesity have long been linked to socioeconomic status – in short – not having enough money (and/or education) can make you fat.

This may be the most obvious explanation for an intriguing finding by Jessica Jones-Smith and colleagues published in JAMA, showing that opening or expansion of American Indian-owned casinos were associated with a significantly decreased risk of childhood obesity in those communities.

The basis for this hypothesis was the simple fact that for some American Indian tribes in the US, casinos provide a significant source of income for the people living in those communities.

The researchers looked at repeated cross-sectional anthropometric measurements from fitness testing of American Indian children (aged 7-18 years) from 117 school districts that encompassed tribal lands in California between 2001 and 2012, of which 57 gained or expanded a casino, 24 had a preexisting casino but did not expand, and 36 never had a casino.

Using changes in the number of slot machines per capita as a measure of economic expansion (each slot machine was associated with an increase of around $550 in per capita annual income), the researchers found that every additional slot machine per capita reduced the probability of childhood overweight and obesity by about 0.2 percentage points.

Given that on average the opening or expansion of a casino resulted in about 13 additional slot machines per capita – the average reduction in obesity probability would be about 2.6% points.

Obviously, as the authors acknowledge, factors other than simple economics may have played a role in this relationship.

Thus, as always with these type of studies,  assuming a direct causal relationship between adding slot machines and reducing childhood obesity obesity may be too simplistic.

Less critical observers may nevertheless jump to the conclusion that battling childhood obesity in tribal communities may be as easy as replacing vending machines with slot machines.

@DrSharma
Copenhagen, DK

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Wednesday, March 5, 2014

Why The 500% Increase in Severe Obesity Should Concern Us All

sharma-obesity-waiting-timeAs someone working in a tertiary care bariatric clinic, I have often been accused of just seeing the tip of the iceberg.

Unfortunately, it is this “tip” that is growing the fastest, when it comes to the increase in obesity rates across Canada.

Thus, a paper by Laurie Twells and colleagues from Memorial University, St John’s, Newfoundland, published in CMAJ Open, not only predicts that overall obesity rates in Canada will continue to grow well into 2019, but also shows that between 1985 and 2011, the rates of Canadian adults with a BMI greater than 40 have increased from 0.3 to 1.6%.

Over the same time period, rates of Canadians with Class I and  Class II obesity have increased from from 5.1% to 13.1%, from 0.8% to 3.6%.

So, while the efforts in obesity prevention may or may not eventually lead to fewer people getting obese in the first place, our strategies are miserably failing those, who already have the problem.

This should come as no surprise, as Canada has yet to come up with a coherent strategy to address adult obesity.

As the authors note, there is indeed a wide variability between provinces when it comes to access to obesity treatments, irrespective of whether this is bariatric surgery or behavioural programs in primary care.

There also continues to be a significant deficit in training and education of health professionals in best-practices in the prevention of weight gain and obesity treatments.

Unfortunately, the impact of this lack of access and resources affects those the most, who already have the problem. They neither have the time to wait for prevention measures to kick-in nor do I expect measures aimed at prevention to lessen their health burden – they need treatments.

It would of course help if we actually had better treatments. Given a 95% failure rate of “Eat-Less-Move-More” approaches to obesity management, there is no doubt that the sooner we find more effective treatments, even if they only help prevent progression in those who already have the problem, the better for everyone.

After all we are talking about our families, friends, colleagues, neighbours – people, whose struggles with this condition should concern us all.

@DrSharma
Edmonton, AB

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Wednesday, February 5, 2014

Obese Kids Drink As Much Pop As Skinny Kids?

sharma-obesity-beveragesAmong all of the popular targets for population-based solutions to the obesity dilemma, sugar-sweetened beverages (SSB) probably head the list.

There is indeed no arguing with the fact that the sugar in these beverages adds a substantial amount of calories to the average Canadian’s diet – calories, with little (if any) nutritional value. Thus, in any simplistic equation of  ”calories in and calories out”, SSBs would certainly stand out as a prime candidate for driving obesity.

Unfortunately, this notion (at least the simplistic variants of this notion) are not as unequivocally supported by the actual research on this issue, as some would have us believe.

Case in point is the latest study on this issue by Lana Vanderlee and colleagues from the University of Waterloo School of Public Health (host of the upcoming 4th National Obesity Student Meeting, June 18-21, 2014), published in the Journal of School Health.

The study looks at data from 10,188 youth (ages 13-18) from Hamilton and Thunder Bay, Ontario, and Prince Edward Island (PEI) in 2009 to 2010, who answered 12 questions regarding beverage consumption during the previous day, along with self-reported height, weight, physical activity levels, and demographic information.

While four out of five youth reported to have consumed at least one SBB on the previous day, almost one in two reported consuming three or more!

Although there were interesting geographic differences in SSB consumption, the researchers found virtually no relationship between BMI and SSB consumption, no matter how they analyzed the data.

Funnily enough, PEI, where kids reported the lowest SSB consumption, turned out to have the highest number of overweight kids.

Despite all the usual caveats with studies based on self-reported rather than objectively measured data, one thing is clear: if SSBs are indeed a relevant driver of the obesity epidemic, the data certainly don’t shout it out.

Obviously, one explanation could well be that the methodology of the study was not robust enough to identify this relationship (although I am certain that had a positive relationship been found, this study would  have been widely paraded as conclusive evidence to support the immediate ban of SSBs).

On the other hand, a rather simple explanation for this finding may be that no such relationship exists. Indeed, it is scientifically not at all unreasonable, when your data fail to support your hypothesis, to question the hypothesis.

This is not to say that copious consumption of SSBs may not be detrimental to health – that may well be the case.

But it does seem that the popular story line suggesting that SSBs are anywhere as important a “cause” of the obesity epidemic as proponents of this hypothesis make them out to be, certainly needs to be taken with a grain of salt.

This issue becomes even more important, if such efforts distract us from identifying and addressing the “real” causes of the problem (which I am willing to wager, in the end, may well have surprisingly less to do with either diet or physical activity than we think).

@DrSharma
Edmonton, AB

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Wednesday, December 11, 2013

Are There Merits To Subtyping Obesity?

sharma-obesity-etiological-approach1Regular readers may recall that several years ago we proposed that it was time to move beyond considering obesity a homogeneous entity (as defined by BMI alone) and suggested that clinicians may be better off using an “etiological framework” for assessing and addressing the diversity of factors that drive weight gain.

This notion, that obesity is not a homogeneous condition, is something other researchers are now slowly catching up with.

One example of how “mainstream” thinking is gradually embracing the concept of heterogeneity in obesity is a recent paper by Allison Field and colleagues from Harvard Medical School published in JAMA.

In this paper the authors state that,

“One reason for the lack of stronger associations with risk factors or more consistently successful treatment is that all types of overweight and obesity are often grouped together. This approach potentially obscures strong associations between risk factors and specific subtypes of obesity.”

This is a problem that we have long lamented and regular readers will be well aware that this was the very basis for developing the Edmonton Obesity Staging System (EOSS) as a way to classify obese patients based on how “sick” they are rather than just on how “big” they are.

While the authors of this paper may yet have to familiarize themselves with the literature on this issue, there is certainly no reason to expect why individuals with higher EOSS stages will not be the ones to benefit more from obesity interventions than those in the low-risk groups.

Depite making a few good points about advances in molecular epidemiology, this article lacks sharp thinking in that it does not clearly distinguish between “etiological” and “phenotypic” heterogeneity of obesity.

While the former applies to the many drivers of obesity (which we have categorized as predominantly affecting metabolism, ingestive behaviour and/or physical activity), the latter applies to the many consequences of obesity (which we have categorized as affecting physical, mental and functional health).

As we have previously pointed out, the two are not necessarily related.

Thus, two individuals, gaining weight for entirely different reasons (e.g. food insecurity vs. binge-eating syndrome), may well present with exactly the same amount of excess body fat and identical clinical complications (e.g. diabetes, reflux disease and urinary incontinence).

On the other hand, two individuals, gaining weight for exactly the same reason (e.g. on anti-psychotic medications), may present with quite different complications (e.g. sleep apnea vs. osteoarthritis).

Thus, while ‘subtyping’ of obesity at the molecular or genetic level (as suggested by the authors), may well be of interest, there are already clinically meaningful ways to subtype obese individuals both with regard to etiology and clinical risk.

Nevertheless, the authors are certainly correct in their statement that,

“Obesity is a heterogeneous and complex disease influenced by exogenous and endogenous exposures. Stratifying obesity into meaningful subtypes could provide a better understanding its causes and enable the design and delivery of more effective prevention and treatment interventions.”

It is good to see “mainstream” thinking on this issue finally catching up with this concept.

@DrSharma
Berlin, Germany

ResearchBlogging.orgField AE, Camargo CA Jr, & Ogino S (2013). The merits of subtyping obesity: one size does not fit all. JAMA : the journal of the American Medical Association, 310 (20), 2147-8 PMID: 24189835

 

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Thursday, December 5, 2013

At-Risk is Not The Same as Unhealthy

sharma-obesity-cardiometabolic-risk1Clearly, this week’s posts on the two articles suggesting that there is no such thing as “healthy obesity” have hit a nerve.

I do not wish to repeat my previous criticisms of these two articles, which you can read here and here.

But I do wish to take the opportunity to set the record straight, that I do indeed take obesity seriously!

I am certainly well aware of the many health problems, emotional pain and physical limitations that are commonly associated with excess weight.

After all, I work in a clinic that provides all forms of behavioural, medical and surgical treatments for obesity and can certainly attest to the substantial health benefits of successful obesity management.

I am also well aware that with increasing BMI levels, it becomes harder and harder to find obese people who one would consider to be perfectly healthy.

As we showed in our analyses of NHANES data, EOSS Stage 0 individuals make up only 15% of individuals in the BMI 25 to 30 range, decreasing to 8% of individuals in the BMI 30 to 35 range and dropping to less than 5% in those with a BMI greater than 35.

Although we regularly see individuals with EOSS Stage 0 even at BMI levels well beyond 40, these are indeed rare individuals – the vast majority of our patients present with EOSS Stage 2 or higher.

Thus, my “advocacy” for the existence of “healthy obesity” has nothing to do a lack of recognition or even underestimation of the considerable health risks and problems related to excess weight.

Rather, my insistence on not immediately assuming that everyone with a higher BMI is in immediate need of medical attention, is motivated by our ability to look at individual risk rather than having to simply rely on statistical probabilities.

Fortunately, we have a rather good understanding of the key underlying risk factors that mediate cardiometabolic risk (high blood pressure, dysglycemia and dyslipidemia), which, together with smoking, account for virtually 90% of all cardiovascular risk. There is nothing mysterious about these risk factors and all can (and should) be easily measured in clinical practice.

Thus, whether an obese person is actually at increased cardiometabolic risk or not does not have to be a guessing game – a few simple physical and laboratory tests will quickly provide a clear answer (whereas stepping on the scale will not!).

This is the whole point of the argument. Why should we jump to the conclusion that anyone with a higher BMI is unhealthy based on BMI alone, when it is so simple to determine actual risk?

A common counterargument is that, because the vast majority of people with higher BMI’s are at increased risk, it may be easier to simply tell everyone to lose weight.

But that is exactly where the problem lies. Losing weight is anything but easy and may in fact cause harm (if the methods employed are unhealthy and/or weight recidivism adversely affects emotional and physical health).

Based on our calculations in the US-NHANES data set, recommending that anyone with a BMI greater than 25 loses weight would include almost 10 million individuals in the US, who we would consider EOSS Stage 0, i.e. perfectly healthy.

Readers will hopefully agree that 10 million is not a trivial number by any standard – these are the people who stand to be harmed by blanket recommendations that label all overweight and obese people as unhealthy – the risk/benefit ration for these individuals may well be on the side of risk rather than benefit.

At a minimum, these 10 million people deserve the courtesy of health professionals actually measuring their actual risk before making pronouncement as to their prognosis.

I strongly feel that in our public health messaging (and clinical practice guidelines) – both sides can stand alongside each other.

Yes, excess weight can increase the risk of cardiometabolic risk factors (and other health problems) – simple tests in your doctor’s office can help determine these risks.

On the other hand, not everyone carrying a few extra pounds is at immediate risk of developing diabetes or heart attacks (or stands to benefit from obsessing about their weight) –  again, simple tests in your doctor’s office can help identify those at low risk.

To me the real question of interest is not whether or not “healthy obese” people exist – they do!

The interesting question is what these individuals can teach us about the sociopsychobiology of obesity. What behavioural or biological factors keep these individuals healthy? Perhaps there are learnings here that can help “unhealthy obese” individuals live healthier lives.

@DrSharma
New Delhi, India

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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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