In contrast to other major global health issues such as tobacco and childhood malnutrition, obesity is rapidly increasing worldwide. Obesity is already a major public health challenge in many middle-income countries, which places a greater urgency on data collection and dissemination of information outlining the risks associated with obesity.

The growing incidence of obesity is one of the most challenging contemporary threats to global public health. The World Health Organisation (WHO) estimates that more than half the world’s adult population is either overweight (39%) or obese (13%). Since 1980, the worldwide prevalence of obesity has more than doubled and statistics also show a significant increase in incidences of childhood obesity. In 1990, 4.2 per cent of the world’s children were overweight or obese, and by 2010, this percentage had risen to 6.7 per cent. This trend is expected to reach 9.1 per cent, or 60 million, by 2020.

Obesity is a major contributor to Type 2 diabetes, with estimates showing that eliminating obesity from the population can potentially reduce the incidence of Type 2 diabetes by over 40 per cent. Diabetes is the fastest-growing chronic condition in Australia, with approximately 280 people developing it every day, while in New Zealand, 243,125 people have been diagnosed. As there is currently no cure, the condition requires lifelong management.

Health and wellbeing impacts

The effects of being obese are significant public health problems that are associated with a broad range of chronic clinical conditions and premature mortality. People who are obese are far more likely to develop problems with their blood pressure, cholesterol, triglycerides and insulin resistance. Risks of coronary heart disease, ischemic stroke, Type 2 diabetes and a range of cardiovascular disease subtypes also increase steadily with increasing BMI. Raised BMI increases the risk of cancer of the breast, colon, prostate, endometrium, kidney and gall bladder. Mental health and eating disorders are also associated with being overweight or obese.

Anaesthesia of patients who are obese can be problematic because of the increased risk of high blood pressure, heart disease, decreased oxygen delivery, hiatus hernia, and a higher risk of regurgitation and aspiration. Obtaining intravenous access and performing regional anaesthesia may also be difficult. For these and other reasons, it is advisable that in the first instance, patients who are obese try to lose weight prior to elective surgery.

An increasing number of research studies have demonstrated the link between obesity and poorer outcomes following surgery. Patients with a BMI over 40 suffer disproportionately greater complications and morbidity than those who are less obese or in the recommended weight range. Compared with patients in the recommended weight range, those with the modified metabolic syndrome (obesity, hypertension, treated diabetes) had two to three times higher risk of cardiac complications, 1.5 to 2.5 times higher risk of pulmonary complications, two times higher risk of coma and stroke, and a three to seven times higher risk of acute kidney injury.

What can be done?

RACS believes a combination of preventative measures and an increase in the availability of treatment options for those who are already obese is the most effective way to address obesity. Evidence suggests that taking steps to maintain a healthy weight and lifestyle throughout life is one of the most important ways to protect against many types of cancer and a range of other diseases described as, “the largest and most rigorous evaluation of preventative strategies undertaken anywhere in the world.” It found that a 10 per cent tax on unhealthy non-core foods would lead to substantial health gain and considerable future cost savings by averting treatment of obesity-related diseases. The WHO also recognises the influence of price on food choices and supports a fiscal approach.

Examples of other preventative measures include better labelling on food packaging and public education programs. There is evidence to suggest that education programs can have a positive impact on physical activity levels.

Surgery for weight loss

All individuals seeking weight loss should begin with non-surgical therapy and consider bariatric surgery only if they are unable to achieve sufficient long-term weight loss and co-morbidity improvement. Clinical decisions should be based on a comprehensive evaluation of the patient’s health and prediction of future morbidity and mortality.

Surgical options to address obesity include gastric bypass surgery, laparoscopic adjustable gastric band surgery or sleeve gastrectomy. RACS does not endorse any particular procedure.

There is strong evidence to suggest that surgery is an effective intervention for weight loss in the morbidly obese (BMI > 40) where non-surgical interventions have been ineffective, and that this may reduce the long-term costs and health impacts of obesity.Randomised controlled trials have shown that surgical treatment was statistically significantly more effective than nonsurgical therapy in reducing weight over 24 months, and that this weight loss remained present after 10 years. For obese patients with Type 2 diabetes, surgery can rapidly improve control of blood sugar and cardiovascular risk factors.

There are similar benefits for patients with a BMI > 35. Generally non-operative treatment is advised for class I obesity (BMI 30–35), however where there are comorbidities there may still be a role for bariatric surgery.


Read the complete position paper at the link below.