Advances in understanding obesity


Traditional health advice about this global epidemic emphasises behavioural change above all while failing to recognise obesity as a disease. Pharmacists can help change the narrative.

Obesity is a chronic progressive disease that causes complications including heart disease, diabetes and many cancers. We have no cure, and to date prevention has been largely unsuccessful.

The major determinants of obesity are set in early life involving genetic, epigenetic, and metabolic programming. These generate a propensity to become obese that is enabled by our obesogenic environment.1 Obesity is only peripherally associated with personal choice, and the concept that a healthy diet and plenty of exercise is the solution is simplistic and does not work. This is because our weight (fat) is regulated by the brain, and sustaining significant weight loss is extremely difficult for the vast majority of those living with obesity.2

It is critical to look at the risk and benefits of the current broad, holistic health recommendations. The benefits of a healthier diet and regular physical activity are well known, as they improve quality of life and reduce the risks of chronic disease including obesity.

However, these changes alone do not have a major sustained effect on body weight for the majority of those living with obesity, and the prevention and treatment of obesity remains unaddressed.

Those living with obesity understand this all too well. Their perception of repeated personal failure and lack of control is reinforced by public health messaging and headline images3 of bodies layered with adipose tissue. There is now clear evidence that this is harmful.4

Barriers to prevention and management

Weight bias, stigma and discrimination are the greatest barriers to preventing and managing obesity and its numerous biological, psychological and social complications. Internalised weight stigma causes weight gain, reduces physical activity, generates stress, depression, eating disorders, and increases cardiometabolic risk.5,6 Blaming and shaming will not and does not work.

The distorted public perceptions of obesity prevention and management are shared by many health professionals and most of those living with obesity. The knowledge and perception gaps are extraordinary and not consistent with current scientific evidence.7 Strangely, health professionals and their patients living with obesity believe diet and exercise are the most effective measures to manage obesity. There is much less faith in therapies with proven efficacy and documented improvement in health outcomes.7

If we approached heart disease, diabetes and cancer with a similar diet and exercise mantra alone, we, as health professionals, would be considered incompetent and negligent. Of course, we do not hesitate to use lifesaving interventions and engage our patients in comprehensive chronic disease management including behavioural change and healthy choices for these conditions. We should do the same for our patients with obesity. Pharmacists can play an important role in changing the narrative on obesity and effecting real change in the lives of those living with obesity.

The conventional narrative of obesity built around unproven assumptions of personal responsibility and misconceptions about the causes and remedies of obesity creates harm to individuals and to society.

Understanding the gap between scientific evidence and the conventional narrative may help reduce weight bias and alleviate its numerous harmful effects. Media professionals, policymakers, educators, healthcare professionals, academic institutions, public health agencies and governments must ensure that the messages and narrative of obesity are free from stigma and coherent with modern scientific evidence.4

Pharmacists also have an important role in the team delivering effective therapies within the context of chronic disease management. They need a fundamental understanding of evidence-based therapies such as meal replacements, including the special role of very low calorie diets8; pharmacotherapy, which is likely to become a mainstay of long-term therapy; and bariatric metabolic surgery – currently the most effective therapy.9

Recent advances

It’s also important to be updated regularly. An additional combination pharmacological preparation naltrexone/ bupropion (Contrave) became available in February 2019.10 It is a welcome additional fourth pharmacological tool to join phentermine, orlistat and liraglutide. We need all the effective tools available and look forward to additional pharmacological agents currently under evaluation.

The established evidence base behind meal replacements for both short- and long-term weight management has been enhanced by the DiRECT study. This study, performed in primary care in the United Kingdom, showed the remarkable effect of weight loss in patients with obesity and type 2 diabetes.8 Many dietitians in Australia are highly skilled in helping patients use these effective dietary tools.

There have been two significant organisational developments in Australia recently. Until 2019 Australians living with obesity had not been heard. The Weight Issues Network (WIN) now provides that voice by bringing together those with the lived experience of overweight or obesity to represent their perspectives and needs (

Health practitioners focused on managing obesity and its complications have also failed to be adequately represented. The National Association of Clinical Obesity Services (NACOS) was also formed in 2019 to enable a stigma-free health system that provides timely and equitable access to the best available care for the effective management of obesity and its complications ( These two nascent organisations fill major gaps in providing for those living with obesity. They deserve every support.

It’s extraordinary that such a common chronic disease has not been adequately represented. Hopefully, it’s time for that to change. Obesity should be recognised and treated as a chronic disease in healthcare and policy sectors.4

For more information visit the Weight Issues Network at:


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  7. Caterson ID, Alfadda AA, Auerbach P, et al. Gaps to bridge: misalignment between perception, reality and actions in obesity. Diabetes Obes Metab 2019;21:1914–24. At:
  8. Lean MEJ, Leslie WS, Barnes AC, et al. Durability of a primary care-led weightmanagement intervention for remission of type 2 diabetes: 2-year results of the DiRECT open-label, cluster-randomised trial. Lancet Diabetes Endocrinol 2019;7(5):344–55. At:
  9. Lee PC, Dixon J. Bariatric-metabolic surgery: a guide for the primary care physician. Aust Fam Physician 2017;46:465–71. At:
  10. Greenway FL, Fujioka K, Plodkowski RA, et al. Effect of naltrexone plus bupropion on weight loss in overweight and obese adults (COR-I): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. Lancet 2010;376:595–605. At:

PROFESSOR JOHN DIXON MBBS, PhD, FRACGP, FRCP Edin, is Adjunct Professor at Iverson Health Innovation Research Institute, Swinburne University, and the School of Primary and Allied Health, Monash University, Melbourne.

The author’s view may not align with those of PSA.