Arya M. Sharma, MD

Last week it was hard to miss the media barrage following the publication of one of the largest ever global studies on obesity by Mariel Finucane and colleagues on behalf of the Global Burden of Metabolic Risk Factors of Chronic Diseases Collaborating Group in The Lancet.

The researchers estimated trends in BMI for adults 20 years and older in 199 countries and territories including data from over 960 country-years and 9·1 million participants.

The findings are indisputable: Between 1980 and 2008, mean BMI worldwide increased by 0·4 kg/m² per decade for men and 0·5 kg/m² per decade for women.

Only a handful of countries stayed weight stable - the regions with almost flat trends or even potential decreases were central and eastern Europe for women, and central Africa and south Asia for men.

The largest increases were seen in the Oceanic countries, where current population averages are hitting 33 kg/m² (no - the USA is not the fattest country in the world!).

A most useful interactive info graphic that illustrates these trends for all of the countries included in this study can be found on the Washington Post website.

So now what?

With almost 1.46 billion adults overweight (BMI ≥25 kg/m2), including 500 million clinically obese (BMI ≥30 kg/m2), it will take decades before there is any hope of reversing this global trend - even the most optimistic public health experts are skeptical that these numbers are likely to significantly drop before the middle of this century

Essentially, as blogged before, this means that we finally need to get serious about obesity control and treatment. But herein lies the problem.

Not that wide scale treatment of a chronic condition is not possible or unlikely to be effective.

The same issue of The Lancet incidentally also features an article on global trends in high blood pressure - here rates are decreasing (by almost 8 mmHg systolic in high-income countries!

Given that obesity is one of the strongest drivers of high blood pressure (especially in younger adults), as pointed out by Sonia Anand and Salim Yusuf in an accompanying editorial, one explanation for this decrease in blood pressure levels could be the better identification and treatment of patients with hypertension - something that can generally be achieved for a a few cents a day with existing medications.

Indeed, the widespread use of medications for lowering blood pressure and cholesterol levels as well as better diabetes control (in addition to reductions in smoking rates) have been implicated in the continuing fall in cardiovascular deaths despite increasing obesity rates in high-income countries.

Unfortunately, no such medications are currently available for obesity.

Bariatric surgery, clearly the most effective long-term treatment for obesity, is likely to be (and perhaps should be) reserved for more severe cases. Although over 500,000 bariatric operations were performed globally last year (and hopefully benefitted the majority of patients who underwent these procedures) this is somewhat akin to scratching at an iceberg with a teaspoon in terms of global impact.

In overweight individuals at lower BMI levels, modest weight loss (3-5%) can likely be achieved and sustained with behavioural modification alone. Sadly, for the many individuals in the moderate to higher BMI range, long-term success with lifestyle change alone is likely to remain the exception (but kudos to those who can do it!).

That is of course, unless we come up with effective and reasonably safe pharmacological treatments for obesity, similar to those that exist for high blood pressure or elevated cholesterol levels. Not that blood pressure or cholesterol-lowering medications are completely without risk - but on average, when used as indicated with proper monitoring, substantially more people benefit from these medications than sustain serious harm from them (although this no doubt happens).

Unfortunately, as regular readers of these pages will appreciate, bringing effective anti-obesity drugs to market (or keeping them there) is not easy.

In contrast to the often rather dubious manufacturers of the many useless (and often dangerous) “all-natural” “scientifically-proven” metabolic boosters, fat burners, and appetite suppressants, readily available on the internet, in health stores, and on supermarket shelfs, pharmaceutical companies are held to vastly higher standards and have to invest billions into well-controlled clinical trials that include 1000s of volunteers before they can even remotely hope to bring any new drugs to market - the safety standards for obesity drugs (perhaps unfairly?) appear even higher than for other indications.

In addition, any obesity drugs that do eventually make it to market are likely to be rather pricey as the companies seek to recover their substantial development costs and still turn profits for their shareholders.

This means that for the vast majority of people living with excess weight today, the only option will be to either continue on their journey of yo-yo dieting and weight cycling (with all of its profoundly negative psychological consequences) or to accept their excess weight and try to live as healthy and active lives as they possibly can (read: Health at Every Size = HAES).

This also means that health professionals need to be far more knowledgeable in providing advice and support to their patients and be far more realistic in their expectations of them.

As blogged before, we as health professionals need to learn to identify and address underlying psychosocial and biomedical drivers of weight gain (rather than simply blaming it on overindulgence, sloth, and lack of will power), counsel patients on realistic and sustainable behaviour change, acknowledge the considerable work involved to achieve and sustain even modest weight loss (for many patients simply helping them prevent further weight gain can be success!), and, perhaps most importantly, focus on improvements in health and quality of life rather than obsess about numbers on the scale.

In the meantime, let us also get more serious about addressing the many societal drivers of this global obesity epidemic - even if it may mean overhauling our food-supply systems, restructuring our work and family lives, rebuilding our cities, cleaning up the environment, and perhaps (for some of us at least) working less and sleeping more.

AMS
Edmonton, Alberta

Two of the most commonly proposed population-wide measures to prevent and reduce the health burden of obesity are a simple front-of-package food label (green-yellow-red) and the taxation of junk foods.

But would such measures truly be cost effective?

This question was now addressed by Sacks and colleagues from Deakin University, Melbourne, Victoria, Australia, who modeled the cost effectiveness of ‘traffic-light’ nutrition labelling and ‘junk-food’ tax in a paper just published in the International Journal of Obesity.

For traffic-light labelling, the researchers estimated changes in energy intake based on an assumed 10% shift in consumption towards healthier options in four food categories (breakfast cereals, pastries, sausages and preprepared meals) in 10% of adults.

For the ‘junk-food’ tax, price elasticities were used to estimate a change in energy intake in response to a 10% price increase in seven food categories (including soft drinks, confectionery and snack foods).

Changes in population weight and body mass index by sex were then estimated based on these changes in population energy intake, along with subsequent impacts on disability-adjusted life years (DALYs).

Based on the 2003 Australian population, both interventions would reduce mean weight (traffic-light labeling: 1.3 kg; ‘junk-food’ tax: 1.6 kg) and avert a substantial number of DALYs (traffic-light labeling: 45 100 years and ‘junk-food’ tax: 559 000 years).

The authors concluded that despite cost outlays of AUD 81 million for traffic-light labeling and AUD 18 million for ‘junk-food’ tax, both interventions would be cost-effective and excellent ‘value for money’.

Obviously, this would be great, if indeed the underlying assumptions were correct.

Interestingly, however, the same authors, in a previous study, found virtually no effect of traffic-light-labeling on driving UK consumers to make healthier choices. Regular readers may also recall previous posts on the rather small effects of taxing sodas or other “unhealthy” foods.

This is not to say that population-wide measures to prevent or reduce the burden of obesity, if found effective, should not implemented.

However, we must also remember that any such measures, even if effective in reducing the average weight of the population by a few kilos, will still leave the millions already struggling with obesity in want of treatments.

AMS
Toronto, Ontario

Sacks G, Veerman JL, Moodie M, & Swinburn B (2010). ‘Traffic-light’ nutrition labelling and ‘junk-food’ tax: a modelled comparison of cost-effectiveness for obesity prevention. International journal of obesity (2005) PMID: 21079620

Sacks G, Rayner M, & Swinburn B (2009). Impact of front-of-pack ‘traffic-light’ nutrition labelling on consumer food purchases in the UK. Health promotion international, 24 (4), 344-52 PMID: 19815614

This morning I am presenting a plenary lecture on the Etiological Assessment of Obesity at the Global Obesity Summit 2010, Jackson, Mississippi.

As readers may know, Mississippi currently leads the US in both adult and childhood obesity rates.

Although a number of programs exist to address obesity in schools, communities and rural populations, Mississippi lacks a coordinated strategy to expand obesity research, education, clinical treatment and prevention.

The Organising Committee is co-chaired by my friend and colleague John Hall, who has made considerable contributions to our understanding of obesity related hypertension. John is the Arthur C Guyton Professor and Chair of Physiology & Biophysics and currently the Associate Vice Chancellor for Research at the University of Mississippi Medical Centre.

Faculty of this Summit includes a distinguished panel of obesity researchers and clinicians as well as politicians, community leaders and senior administrators from Mississippi and other US states.

The Summit even features the Honourable Bill Clinton, 42nd President of the US, who will address the delegates regarding the need for more concerted action to address the obesity crisis.

The scientific program is nicely framed by over 130 original poster presentations on topics ranging from basic science to population health.

I certainly look forward to a most stimulating and lively discussion with my many colleagues from across the US and other countries.

AMS
Jackson, Mississippi

I have previously blogged about the importance of maternal ill-health and malnutrition as a key driver of the childhood obesity epidemic. Not surprisingly, this statement appears even more relevant, when we look at the emerging obesity epidemic in developing countries.

Thus in an article just released online in Obesity Reviews, Avita Usfar and colleagues examine obesity as a possible consequence of a a poverty-related nutrition problems.

As the authors note, in developing countries like Indonesia, although undernutrition is still a major public health problem, especially in the very poor, obesity is emerging as a broader public health challenge.

Thus, in the Indonesian national basic health research 2007, double-digit percentages of overnutrition were found among all age groups, with similar magnitude in urban and rural areas and higher prevalence in adult female.

While 14% of children under the age of 5 years were undernourished, 12% of their counterparts were overnourished; for 6-14 years 10% were undernourished while 6% were overnourished; for 15 years and above 15% were undernourished and 19% were overnourished.

Stunted adults were 1.2 times more likely to be overweight than non-stunted adults.

The authors note that it is important for Indonesia to target nutrition intervention for female adolescents, pregnant woman to first 2 years of life, initiate nutrition education for school-age children and disseminate healthy eating messages. The article also calls for the development of nutritional guidelines and for the use of lower BMI cut-offs to define obesity in Indonesians.

Overall, same issues probably apply for other developing countries, where the prevelance of overnutrition is fast overtaking the prevalence of undernutrition - a situation that was unthinkable just a few decades ago.

AMS
Edmonton, Alberta

Usfar AA, Lebenthal E, Atmarita, Achadi E, Soekirman, & Hadi H (2010). Obesity as a poverty-related emerging nutrition problems: the case of Indonesia. Obesity reviews : an official journal of the International Association for the Study of Obesity PMID: 20977602

Yesterday, at the 3rd Conference on Recent Advances in the Prevention and Treatment of Childhood & Adolescent Obesity, in Hamilton Ontario, I moderated a debate on whether or not advertising to kids should be regulated

The contestants were Dr. Yoni Freedhoff (of Weighty Matters fame), who eloquently supported the call for regulation, and Dr. Laurette Dube (Professor and James McGill Chair of consumer and lifestyle psychology and marketing, Desautels Faculty of Management, McGill University, Montreal), who, while not fully disagreeing with Freedhoff, made the point that regulating the food industry would be neither feasible nor enough.

Both debaters agreed that doing nothing was not an option, a view supported by the publication of the latest figures on adolescent and adult obesity in Canada.

Thus, in a paper just released online in Obesity Reviews, Ian Janssen and colleagues (Queens University, Kingston, Ontario and University of Ottawa, Ontario), describe the dramatic increased in the prevalence of abdominal obesity in Canadian adolescents and adults between 1981 and 2009.

Based on three national health surveys conducted in 1981, 1988 and 2007-2009, the prevalence of abdominal obesity in 12- to 19-year-old adolescents, measured as an increased waist circumference was 1.8% in 1981, 2.4% in 1988 and 12.8% in 2009, representing a 6-fold increase.

During the same time period, the corresponding rates for abdominal obesity in 20- to 69-year-old adults were 11.4%, 14.2% and 35.6%.

Between 1981 and 2009, the mean waist circumference increased more in women than in men both in adolescents (4.2 vs. 6.7 cm) and adults (6.7 vs. 10.6 cm).

While over 90% of adults with a BMI over 30 were also considered abdominally obese, it is important to note that abdominal obesity was also present in 35% of overweight adults (in the BMI range 25-30). This is an important finding, as it shows that simply being overweight can be associated with abdominal obesity, the main determinant of obesity related cardiometabolic risk.

Whether debating the pros and cons of regulating advertising to kids will effectively change this alarming situation in the foreseeable future certainly remains doubtful but I do agree that any kind of debate that draws attention to this issue is probably a good idea.

As Freedhoff pointed out (quoting Yale University’s David Katz), “When faced with a flood, stacking sand bags is a useful response - even if no single bag will stop the flood, each bag increases your chance of keeping the waters at bay”.

AMS
Edmonton, Alberta

Janssen I, Shields M, Craig CL, & Tremblay MS (2010). Prevalence and secular changes in abdominal obesity in Canadian adolescents and adults, 1981 to 2007-2009. Obesity reviews : an official journal of the International Association for the Study of Obesity PMID: 20977603