According to experts, obesity has been misunderstood for quite some time. Prof Donal O’Shea, consultant endocrinologist and longstanding campaigner for the prevention of obesity, says that the current message most doctors are giving to patients about obesity is not working. Simply telling people to eat less and exercise more does not count as treatment. Weight gain is 90% irreversible for 90% of people, so a broader examination of lifestyle with prevention in mind is much more important. At last year’s Irish Medical Organisation (IMO) annual conference, Prof O’Shea outlined the complexities saying there are 198 determinants of obesity in seven groups, five of which are outside people’s control. Even if you do lose weight, it will likely come back.

That said, there have been a number of breakthroughs in recent years, not least GLP-1 agonists such as semaglutide (Ozempic). Treatment options such as these may help some of the estimated 1.25 million people in Ireland (24% of the population) who live with obesity. But is the illness being categorised correctly in the first place? The Irish Society for Clinical Nutrition and Metabolism (IrSPEN) recently commented on new criteria for the categorisation of obesity, as agreed by an international expert group. This Lancet Commission comprises 58 doctors, patients and experts who have been working to achieve a consensus on the understanding, diagnosis and treatment of obesity. They have categorised obesity into: (a) clinical obesity, where excess adiposity prevents the normal function of bodily organs; and (b) pre-clinical obesity, where excess adiposity exists and organs are functioning normally but are at risk. Of note, the Commission recommends not relying solely on body mass index (BMI) to diagnose obesity as this may lead to under- or over-diagnosis.

According to the Commission: “People with clinical obesity have reduced organ function (such as breathlessness or heart failure) and/or have substantial trouble with movement and day-to-day activities such as bathing, dressing, eating and continence – due to excess body fat.” Whereas “people living with pre-clinical obesity have excess body fat but do not have reduced organ function and can complete day-to-day activities unhindered.” The Commission added that people with pre-clinical obesity “have increased risk of developing clinical obesity and other diseases such as type 2 diabetes, cardiovascular disease and some cancers.” Successful treatment “should be measured by the improvement of signs and symptoms, rather than weight loss alone.”

The issue of stigma and blame was mentioned by Vicky Mooney, a representative of the European Coalition of People living with Obesity and a member of the Commission representing patients. “Weight based bias and stigma are major obstacles in efforts to effectively manage clinical obesity and pre-clinical obesity,” she said. This was echoed by Prof Edward Gregg of the RCSI, also a member of the Commission, who cited the importance of public understanding of the disease and its two new categories.

Prof Carel le Roux, president of IrSPEN and a member of the Commission, remarked on the importance of the new categorisation in policy development, investment planning and decision making in public health services. “Policy makers should ensure adequate and equitable access to evidence-based treatments for individuals with clinical obesity and pre-clinical obesity as appropriate.” With this new consensus, Prof le Roux said: “We can now start a serious conversation about how we can work together and move away from the idea of weight loss to the idea of health gain to address both clinical obesity and preclinical obesity.” 

For the sake of one in four Irish people, let’s hope he is right.