Should Obesity Be Classified as a Disease?

Dr Fiona Gillison is Head of Department of Health at the University of Bath.

The Royal College of Physicians has sparked debate over recent months by calling for obesity to be classified as a disease in the UK. The aim of doing this is primarily to elevate obesity’s status, encouraging doctors to take it more seriously and potentially unlocking more resources for its treatment and prevention. In addition, it is argued that reclassifying obesity as a disease may help to reduce the stigma felt by people living with obesity, which we know can lead to poor mental health and wellbeing, undermine motivation to lose weight, worsen disordered eating and deter people from seeking help. Few would argue that it would be of great benefit to achieve both of these aims.

But it’s also worth reflecting on whether reclassifying obesity as a disease is necessary to achieve these, and if there are unintended negative consequences that should also be taken into account.

If obesity is a disease, what are health professionals supposed to do about it?

Classifying obesity as a disease assumes that health professionals are best placed to help reduce the prevalence of obesity, and that they are currently held back from doing so by its lack of disease-status. This seems to be a flawed assumption. If we think about what is involved in ‘treating’ obesity this centres on encouraging and supporting people to change their normal daily behaviours over an extended period of time, which is very different from the typical medical and surgical interventions that doctors and nurses are trained to deliver.

Research consistently shows that doctors and nurses are uncomfortable and unconfident in raising the issue of weight with their patients. Training specifically in the provision of behavioural support has led to promising results so it’s not that it can’t be done, but there is little or no training in understanding and supporting behaviour change training in medical and nursing curricula. Similarly, there is little evidence that the services to which people can currently be referred for additional support with changing their diet and physical activity on the NHS (such as exercise referral schemes or weight loss programmes) are any better informed. Thus simply calling obesity a disease will not help as it creates the expectation and demand for action by a body of professionals who are largely untrained in providing the sort of support that people need to reduce and manage their weight.

Yet frustratingly we already have many excellent psychologists and people from other disciplines specialising in behaviour change whose expertise we are not tapping into. Health Psychologists in the UK arguably lead the way in both drawing together behavioural science theory and research into a coherent and systematic set of applied techniques, and presenting these in a user-friendly format for policymakers and practitioners designing and delivering behaviour change interventions. Behavioural science is also now acknowledged as an important part of obesity prevention and treatment nationally, reflected in documents such as NICE guidelines for obesity treatment and the creation and ongoing work of the Public Health England behavioural insights team. Yet despite these very positive steps, the implementation of such guidance and involvement of psychologists in the treatment and prevention of obesity is patchy at best. Reclassifying obesity as a disease may risk further undermining this progress by swinging attention away from behavioural science and back towards medical models and the more traditional type of health professionals (doctors and nurses) who we associate with dealing with ‘disease’.

What message would this reclassification send to the public?

The Royal College of Physicians is progressive in acknowledging the harms of obesity stigma, and calling obesity a disease may certainly help to reduce perceptions of blame towards this aim as they suggest. But it is not certain that this would be the only result. For example, if we call obesity a disease we may imply that obesity is something that doctors are responsible for curing, and that people living with obesity are passengers in the process. Even the best policies and interventions won’t be effective if people don’t work with them, so we need to be careful not to get to a point where people feel no responsibility at all for managing their body weight.

In addition, calling obesity a disease may not always reduce perceptions of blame; if we communicate a message that obesity can be ‘cured’, then will people who remain overweight or obese be subject to negative judgements for not having done the responsible thing with regard to their treatment (i.e., wilfully remaining overweight)? We are aiming for a nuanced message along the lines of “while obesity may not be your fault, you are the only person who can do anything about it”. We should first test how the reclassification would be interpreted by the public before we can be confident that the message will be received as intended.

Perhaps more importantly, calling obesity a disease still communicates that obesity is a problem for an individual rather than something that is beyond any individual’s control. Obesity levels have really only rocketed over the past 30 years, during which time the world has changed immeasurably with respect to how we live, work, travel, spend our leisure time and feed ourselves. This complex set of interacting bio-psycho-social determinants of obesity was recognised by the UK Government in the Foresight report back in 2007. Through these physical, technological, social and cultural changes we have effectively ‘designed out’ physical activity and ‘designed in’ cheap and easy access to high calorie, appetising food.

Human beings on the other hand have changed very little over the past 30 years, and with over 40% of adults engaged in weight loss attempts at any one time we are far from the complacent, lazy or unconcerned population that we are sometimes portrayed. So while obesity certainly impacts people’s health and wellbeing in ways that may require medical intervention, framing it as a disease diverts our attention from the reasons why it is developing into epidemic proportions - and arguably where the solutions lie.

What would be more helpful to do instead?

Commentators have long been suggesting that we should draw on our success in tobacco control when designing our approach to reducing obesity. Our approach to tobacco control involved a broad and multi-faceted set of policies that included making environmental, social, legislative and health care changes which all played a part in reducing smoking prevalence by 30% in the 60 years from 1951 to 2011. It is likely obesity will require an even broader set of measures given the far more complex set of behaviours that we are trying to change. The soft drinks levy is an interesting start, and regulation of the food industry will undoubtedly be another key factor, but there are further steps needed around the design of towns, transport infrastructure, working conditions and housing. Calling obesity a disease may deflect attention from these measures, seeming to shift responsibility downstream to public health and health services.

Whatever the outcome of the current debate, the most positive outcome will only be achieved if we use this increased focus to catalyse us into action. We should be introducing behavioural science into mainstream medical education. While doctors and nurses may not have time to provide lasting behavioural support, if they better understand the process of change we can ensure that people receive consistent messages throughout the health care system and increase their chances of onward referral.

We should also harness the expertise of psychologists with a specialism in behavioural science - who are currently knocking vigorously at the door - to ensure they are routinely involved in the design, delivery and evaluation of interventions to prevent obesity and help people to achieve weight loss. This would enable us to ensure that evidence-based behavioural support is available to all who seek treatment. Finally, if we are expecting both health professionals and people living with obesity to make lasting changes we need to support their efforts through creating an environment that helps them to sustain a healthy weight. If the environment doesn’t change, any ‘treatment’ we give can only be a short term patch that is easily undermined if the conditions that caused obesity in the first place remain the same.