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Arguments For Calling Obesity A Disease #8: Can Reduce Stigma

sharma-obesity-hypothalamusNext, in this miniseries on arguments for and against calling obesity a disease, I turn to the issue of stigma.

One of the biggest arguments against calling obesity, is the fear that doing so can increase stigma against people living with obesity.

This is nonsense, because I do not think it is at all possible for anything to make stigma and the discrimination of people living with obesity worse than it already is.

If anything, calling obesity a disease (defined as excess or abnormal body fat that impairs your health), could well serve to reduce that stigma by changing the narrative around obesity.

The current narrative sees obesity largely as a matter of personal choice involving poor will power to control your diet and unwillingness to engage in even a modest amount of regular physical activity.

In contrast, the term ‘disease’ conjures up the notion of complex biology including genetics, epigenetics, neurohormonal dysregulation, environmental toxins, mental health issues and other factors including social determinants of health, that many will accept are beyond the simple control of the individual.

This is not to say that other diseases do not carry stigma. This has and remains the case for diseases ranging from HIV/AIDS to depression – but, the stigma surrounding these conditions has been vastly reduced by changing the narrative of these illnesses.

Today, we are more likely to think of depression (and other mental illnesses) as a problem related to “chemicals in the brain”, than something that people can pull out of with sheer motivation and will power.

Perhaps changing the public narrative around obesity, from simply a matter of motivation and will power, to one that invokes the complex sociopsychobiology that really underlies this disorder, will, over time, also help reduce the stigma of obesity.

Once we see obesity as something that can affect anyone (it can), for which we have no easy solutions (we don’t), and which often requires medical or surgical treatment (it does) best administered by trained and regulated health professionals (like for other diseases), we can perhaps start destigmatizing this condition and change the climate of shame and blame that people with this disease face everyday.

@DrSharma
Edmonton, AB

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Arguments For Calling Obesity A Disease #4: Limited Response To Lifestyle Treatments

Continuing in my miniseries on why obesity (defined heresharma-obesity-exercise2, as excess or abnormal body fat that affects your health) should be considered a disease, is the simple observation that obesity responds less to lifestyle treatments than most people think.

Yes, the internet abounds with before and after pictures of people who have “conquered” obesity with diet, exercise, or both, but in reality, long-term success in “lifestyle” management of obesity is rare and far between.

Indeed, if the findings from the National Weight Control Registry have taught us anything, it is just how difficult and how much work it takes to lose weight and keep it off.

Even in the context of clinical trials conducted in highly motivated volunteers receiving more support than you would ever be able to reasonably provide in clinical practice, average weight loss at 12 – 24 months is often a modest 3-5%.

Thus, for the vast majority of people living with obesity, “lifestyle” treatment is simply not effective enough – at least not as a sustainable long-term strategy in real life.

While this may seem disappointing to many (especially, to those in the field, who have dedicated their lives to promoting “healthy” lifestyles as the solution to obesity), in reality, this is not very different from the real-life success of “lifestyle” interventions for other “lifestyle” diseases.

Thus, while there is no doubt that diet and exercise are important cornerstones for the management of diabetes or hypertension, most practitioners (and patients) will agree, that very few people with these conditions can be managed by lifestyle interventions alone.

Indeed, I would put to you that without medications, only a tiny proportion of people living with diabetes, hypertension, or dyslipidemia would be able to “control” these conditions simply by changing their lifestyles.

Not because diet and exercise are not effective for these conditions, but because diet and exercise are simply not enough.

The same is true for obesity. It is not that diet and exercise are useless – they absolutely remain a cornerstone of treatment. But, by themselves, they are simply not effective enough to control obesity in the vast majority of people who have it.

This is because, diet and exercise do not alter the biology that drives and sustains obesity. If anything, diet and exercise work against the body’s biology, which is working hard to defend body weight at all costs.

Thus, it is time we accept this reality and recognise that without pharmacological and/or surgical treatments that interfere with this innate biology, we will not be able to control obesity in the majority of patients.

Whether we like it or not, I predict that within a decade, clinical management of obesity will look no different than current management of any other chronic disease. Most patients will require both “lifestyle” and probably a combination of anti-obesity medications to control their obesity.

This does not take away from the importance of diet and exercise – as important as they are, they are simply not enough.

Despite what “lifestyle” enthusiasts will have us believe, diet and exercise are no more important (or effective) for the treatment of obesity, than they are for the treatment of hypertension, diabetes, dyslipidemia, depression, or any other condition that responds to “lifestyle” interventions.

In the end, most patients will require more effective treatments to manage their obesity and all of the comorbidities that come with it. The sooner we develop and make accessible such treatments, the sooner we can really help our patients.

@DrSharma
Edmonton, AB

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Stretching The Rubber Band

Yo-Yo Rubber Band Feb 2014I remember as a kid having a pair of pyjamas that were held up by an elastic rubber band.

It must have been a pretty cheap rubber band, because every few months it would wear out and lose its stretch, so it had to be replaced it with a new band.

Unfortunately, this is not what can be said about the rubber band that I used in my recent TEDx talk to demonstrate what happens when you try to lose weight.

Unlike the cheap band in my pyjamas, the rubber band I used to represent our physiology trying to gain the weight back, never seems to lose its stretch.

No matter how hard or how long we pull, the rubber band keeps wanting to bring our weight back to where we started.

Yes, perhaps for some people, eventually the rubber band may relax (these would certainly be the exceptions) or may be the “muscles” that we use to pull on the band just grow stronger, which makes it seem easier to keep up the pull – but for all we know, in most people, this “rubber band” is of pretty good quality and seems to last forever.

So, how do we take the tension out of the rubber band ?

Well, we do know that people who have bariatric surgery have a much better chance of keeping the weight off in the long-term and we now understand that this has little to do with the “restriction” or the “malabsorbtion” resulting from these procedures but rather from the profound effect that this surgery has on the physiology of weight regain.

Thus, we know that many of the hormonal and neurological changes that happen with bariatric surgery, seem to inhibit the body’s ability to defend its weight and perhaps even appears to trick the body into thinking that its weight is higher than it actually is.

In other words, bariatric surgery helps maintain long-term weight loss by reducing the tension in the rubber band, thus making it far easier for patients to maintain the “pull”.

And that is exactly how we think some of the anti-obesity medications may be working.

For example, daily injections of liraglutide, a GLP-1 analogue approved for obesity treatment, appears to decrease the body’s ability to counteract weight loss by reducing hunger and increasing satiety, thus taking some of the tension out of that band.

Think of it as sprinkling “magic dust” on that rubber band to reduce the tension, which makes it easier for patients to maintain that pull thereby helping them keep the weight off.

Of course, both surgery and liraglutide only reduce the tension as long as you continue using them.

Undo the surgery or come off your anti-obesity meds and the tension in that band comes back as strong as ever.

For readers, who have no idea what I’m talking about, hopefully things will become clearer after you watch my talk by clicking here.

@DrSharma
Edmonton, AB

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How To Interpret Studies On Screen Time And Eating Behaviour

sharma-obesity-kids-watching-tvMuch of the research on the contribution of screen time, sedentariness, food consumption and other factors comes from cross-sectional or longitudinal studies, where researchers essentially describe correlations and statistical “effect sizes”.

To be at all meaningful, analyses in such studies need to be adjusted for known (or at least likely) confounders (or at least the confounders that happen to available).

No matter how you turn and wind the data, such studies by definition cannot prove causality or (even less likely) predict the outcome of actual intervention studies.

Nevertheless, such studies can be helpful in generating hypotheses.

Thus, for example, I read with interest the recent paper by Lei Shang and colleagues from the University of Laval, Quebec, Canada, published in Preventive Medicine Reports.

The researchers looked at cross-sectional data on 630 Canadian children aged 8-10 years with at least one obese biological parent.

While the overall median daily screen time was about 2.2 hours, longer screen time was associated with higher intake of energy (74 kcal) and lower intake of vegetables & fruit (- 0.3 serving/1000 kcal).

This unhealthy “effect” of screen time on diet appeared even stronger among children with overweight.

Thus, there is no doubt that the study shows that,

“Screen time is associated with less desirable food choices, particularly in overweight children.”

The question of course remains whether or not this relationship is actual causal or in other words, does watching more television lead to an unhealthier diet (I am guessing no one assumes that eating an unhealthier diet leads to more TV watching).

Unfortunately, this is not a question that can be answered by this type of research.

Nor, is this type of research likely to predict whether or not reducing screen time will get the kids to eat better.

Indeed, it doesn’t take a lot of imagination to come up with other explanations for these findings that would not require any assumption of a causal link between eating behaviours and television watching.

For one, TV watching could simply be a surrogate measure for parenting style – perhaps parents that let their kids watch a lot of TV are also less concerned about the food they eat.

And, for all we know, reducing TV time may (e.g. by cutting the kids off from TV – or cutting the parents off from a convenient babysitter) in the end make the kids eating behaviours even worse.

Who knows – that’s exactly the point – who knows?

To be fair, the authors are entirely aware of the limitations of such studies:

“This study was cross-sectional, so no causal inference could be made and the possible mechanism is not clear. Although our data collection strictly followed the detailed manual procedure to guarantee the quality control (QUALITY Cohort Technical Documents, 2011), potential bias and errors may still exist in those self-reported questionnaires. A number of potential confounding factors have been adjusted in the regression models, but the results may still be confounded by other known and unknown factors.”

So, while the findings may well fit into the “narrative” of sedentariness -> unhealthy diets -> obesity, we must remain cautious in not overinterpreting findings from these type of studies or jumping to conclusions regarding policies or other interventions.

@DrSharma
Edmonton, AB

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Liraglutide Alters Brain Activity Related to Highly Desirable Food Cues

sharma-obesity-brainLiraglutide, a GLP-1 analogue now available for the treatment of obesity (as Saxenda) in North America, works by reducing appetite and increasing satiety, thus making it easier to lose weight and keep it off (with continuing treatment).

Now, a study by Olivia Farr and colleagues, in a paper published in Diabetologia not only present data showing the presence of GLP-1 receptors in human cortex, hypothalamus and medulla, but also provide functional evidence for altered  brain response to food cues.

After documenting the presence of GLP-1 receptor in human brains using immunohistochemistry, the researchers conducted a randomised controlled placebo-controlled, double-blind, crossover trial in 18 individuals with type 2 diabetes who were treated with placebo and liraglutide for a total of 17 days each (0.6 mg for 7 days, 1.2 mg for 7 days, and 1.8 mg for 3 days).

Using functional MRI neuroimaging studies, the researchers found that liraglutide remarkably decreased activation of the parietal cortex in response to highly desirable (vs less desirable) food images.

They also observed decreased activation in the insula and putamen, areas involved in the reward system.

Furthermore, using neurocognitive testing, the researchers showed that increased ratings of hunger and appetite correlated with increased brain activation in response to highly desirable food cues while on liraglutide.

In contrast, ratings of nausea (a well-known side effect of liraglutide) correlated with decreased brain activation.

As the authors note,

“Our data point to a central mechanism contributing to, or underlying, the effects of liraglutide on metabolism and weight loss.”

These findings no doubt match the reports from my own patients of experiencing less interest in highly palatable foods and finding it much easier to pass up on foods that they would have otherwise found hard to resist.

Clearly, as we learn more about brain function in eating behaviour, we are thankfully moving towards treatments that are clearly proving to be far more effective than just telling patients to “simply eat less” (which I have often likened to telling people with depression to “simply cheer up”).

@DrSharma
Edmonton, Canada

Disclaimer: I have received honoraria for speaking and consulting from Novo Nordisk, the maker of liraglutide

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