Thus, following weight loss, not only does the body need fewer calories, doing the same amount of physical work uses fewer calories than before (the joke is that, if you ran 5K a day to lose weight, you have to run 10K a day to keep it off).
Now, a study by Maria Fernström and colleagues, published in Obesity Surgery, shows increased mitochondrial efficiency following bariatric surgery.
The researchers performed skeletal muscle biopsies in 11 women before and at 6 months after gastric bypass surgery.
Measurements in isolated mitochondria showed a marked increase in coupled respiration (state 3) and overall mitochondrial capacity (P/O ratio) with a non-significant increase in uncoupled (state 4) respiration.
Thus, at 6 months following gastric bypass surgery, both the mitochondrial capacity for coupled, i.e., ATP-generating, respiration increased as well as the P/O ratio improved.
As the authors note, not only would this increased “fuel efficiency” in part explain the decreased basal metabolism often associated with weight loss but also the propensity for weight regain that often follows weight-loss interventions.
Obviously, due to lack of a control group, this study does not demonstrate that these changes are in any way specific to weight-loss following bariatric surgery.
Also, given that the nadir of weight loss is generally not achieved until about 18 months following surgery, the changes observed in this study may not represent the maximum increase in mitochondrial efficiency to be achieved with further weight loss.
Next, 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.
Continuing in my miniseries on why obesity (defined here, 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.
Continuing in my miniseries on reasons why obesity should be considered a disease, I turn to the idea that obesity is largely driven by biology (in which I include psychology, which is also ultimately biology).
This is something people dealing with mental illness discovered a long time ago – depression is “molecules in your brain” – well, so is obesity!
Let me explain.
Humans throughout evolutionary history, like all living creatures, were faced with a dilemma, namely to deal with wide variations in food availability over time (feast vs. famine).
Biologically, this means that they were driven in times of plenty to take up and store as many calories as they could in preparation for bad times – this is how our ancestors survived to this day.
While finding and eating food during times of plenty does not require much work or motivation, finding food during times of famine requires us to go to almost any length and risks to find food. This risk-taking behaviour is biologically ensured by tightly linking food intake to the hedonic reward system, which provides the strong intrinsic motivator to put in the work required to find foods and consume them beyond our immediate needs.
Indeed, it is this link between food and pleasure that explains why we would go to such lengths to further enhance the reward from food by converting raw ingredients into often complex dishes involving hours of toiling in the kitchen. Human culinary creativity knows no limits – all in the service of enhancing pleasure.
Thus, our bodies are perfectly geared towards these activities. When we don’t eat, a complex and powerful neurohormonal response takes over (aka hunger), till the urge becomes overwhelming and forces us to still our appetites by seeking, preparing and consuming foods – the hungrier we get, the more we seek and prepare foods to deliver even greater hedonic reward (fat, sugar, salt, spices).
The tight biological link between eating and the reward system also explains why we so often eat in response to emotions – anxiety, depression, boredom, happiness, fear, loneliness, stress, can all make us eat.
But eating is also engrained into our social behaviour (again largely driven by biology) – as we bond to our mothers through food, we bond to others through eating. Thus, eating has been part of virtually every celebration and social gathering for as long as anyone can remember. Food is celebration, bonding, culture, and identity – all features, the capacity for which, is deeply engrained into our biology.
In fact, our own biology perfectly explains why we have gone to such lengths to create the very environment that we currently live in. Our biology (paired with our species’ limitless creativity and ingenuity) has driven us to conquer famine (at least in most parts of the world) by creating an environment awash in highly palatable foods, nutrient content (and health) be damned!
Thus, even without delving any deeper into the complex genetics, epigenetics, or neuroendocrine biology of eating behaviours, it is not hard to understand why much of today’s obesity epidemic is simply the result of our natural behaviours (biology) acting in an unnatural environment.
So if most of obesity is the result of “normal” biology, how does obesity become a disease?
Because, even “normal” biology becomes a disease, when it affects health.
There are many instances of this.
For example, in the same manner that the biological system responsible for our eating behaviour and energy balance responds to an “abnormal” food environment by promoting excessive weight gain to the point that it can negatively affect our health, other biological systems respond to abnormal environmental cues to affect their respective organ systems to produce illnesses.
Our immune systems designed to differentiate between “good” and “bad”, when underexposed to “good” at critical times in our development (thanks to our modern environments), treat it as “bad”, thereby creating debilitating and even fatal allergic responses to otherwise “harmless” substances like peanuts or strawberries.
Our “normal” glucose homeostasis system, when faced with insulin resistance (resulting from increasingly sedentary life circumstances), provoke hyperinsulinemia with ultimate failure of the beta-cell, resulting in diabetes.
Similarly, our “normal” biological responses to lack of sleep or constant stress, result in a wide range of mental and physical illnesses.
Our “normal” biological responses to drugs and alcohol can result in chronic drug and alcohol addiction.
Our “normal” biological response to cancerogenous substances (including sunlight) can result in cancers.
The list goes on.
Obviously, not everyone responds to the same environment in the same manner – thanks to biological variability (another important reason why our ancestors have made it through the ages).
But, you may argue, if obesity is largely the result of “normal” biology responding to an “abnormal” environment, then isn’t it really the environment that is causing the disease?
That may well be the case, but it doesn’t matter for the definition of disease. Many diseases are the result for the environment interacting with biology and yes, changing the environment could indeed be the best treatment (or even cure) for that disease.
Thus, even if pollution causes asthma and the ultimate “cure” for asthma is to rid the air of pollutants, asthma, while it exists, is still a disease for the person who has it.
All that counts is whether or not the biological condition at hand is affecting your health or not.
The only reason I bring up biology at all, is to counter the argument that obesity is simply stupid people making poor “choices” – one you consider the biology, nothing about obesity is “simple”.
Continuing in my mini series on the pros and cons of considering obesity a chronic disease, I would like to now discuss the perhaps most illogical argument against recognising obesity as a disease that I often hear, “Calling obesity a disease will reduce our efforts at prevention”.
This argument makes virtually no sense at all, as I cannot think of a single “preventable” disease, where calling it a “disease” would have reduced or thwarted prevention efforts.
Whether the aim is to prevent heart disease (dietary recommendations, fitness, smoking cessation), cancers (physical activity, healthy diets, smoking cessation, sunlight exposure), infectious diseases (vaccinations, food safety, hand washing, condom use), road accidents (helmets, seat belts, speed limits), in no instance has calling something a “disease” ever stopped us from doing the utmost for prevention (although more can always be done).
Rather, if you truly embrace the concept that obesity, once established, becomes a life-long problem for which we have no cure (the very definition of “chronic disease”), we should be doubling or even quadrupling our efforts at prevention.
After all, who would want to be stuck with a chronic disease, if it can indeed be prevented?
Governments, NGOs and individuals should be even more enthusiastic about preventing a “real” disease than simply modifying a “risk factor” (which sounds a lot less threatening).
Indeed, if I was working in population health, I’d be all for emphasizing just how terrible and devastating the disease of obesity actually is – all the more reason to double down on efforts to do what it takes to prevent it.
In fact, considering obesity a “real disease” would put all the folks working hard to prevent obesity right up there on par with those working to prevent “real” diseases like cancer, HIV/AIDS, or Alzheimer’s disease.
Thus, the argument that calling obesity a “disease” would somehow distract from efforts to prevent it makes absolutely no sense at all.
New Orleans, LA