Obesity is increasingly at the center of workers’ compensation disputes in New South Wales (NSW), not as a “stand-alone” work injury, but as a consequential condition stemming from an accepted work injury. This often occurs when significant weight gain results from chronic pain, inactivity, or medication following a back or shoulder injury. When evidence establishes, on the balance of probabilities, that obesity has developed as a consequence of an accepted work injury, insurers may be ordered to fund treatment, including bariatric surgery. Additionally, permanent impairment can be assessed for the affected body systems.
The legal foundation for this approach lies in distinguishing between an injury and a consequential condition. In NSW, a worker does not need to prove a new “injury” to obtain compensation for a consequential condition. It suffices to show that the condition results from the accepted injury in an unbroken chain of causation, a principle known as the Kooragang common-sense test.
Legal Precedents and Recent Cases
The Personal Injury Commission (PIC) in NSW regularly applies this approach, relying on authoritative cases such as Kooragang Cement Pty Ltd v Bates. Other significant cases include Kumar v Royal Comfort Bedding Pty Ltd [2012] and Moon v Conmah Pty Limited [2009]. These cases have set a precedent for recognizing obesity and weight gain as compensable conditions.
Recent cases have further solidified this stance. In Williams v Secretary, Department of Justice [2024], the worker’s morbid obesity was accepted as a consequential condition arising from his injuries, with the Commission ruling that bariatric surgery was reasonably necessary. Similarly, in Corton v Nariment Pty Limited t/as The Oakes Bakery [2020], the PIC ordered the employer to fund lap sleeve gastrectomy, finding it necessary due to weight gain after a thoracic spine injury.
Whole Person Impairment (WPI) and Its Assessment
Whole person impairment (WPI) in workers’ compensation is a medical assessment that measures the permanent, long-term loss of function from a workplace injury, expressed as a percentage of the whole person. This percentage is calculated by a medical specialist after the condition has stabilized and is used to determine eligibility for compensation, including lump sum payments.
Permanent impairment in NSW is assessed using the AMA5 guidelines, as modified by the NSW Workers Compensation Guidelines. These guidelines adopt AMA5 in most cases and set out body-system-specific methods. Notably, obesity itself is not rated as a discrete impairment in AMA5; instead, assessors rate the body systems affected, such as musculoskeletal, respiratory, cardiovascular, and gastrointestinal systems, and combine the results.
Impact of Obesity on WPI Outcomes
Consequential conditions produce rateable impairments in relevant systems, provided the evidence supports causation back to the original work injury. For example, obstructive sleep apnea may be rated under respiratory impairments, while knee or hip degenerative changes are assessed under lower extremity impairments.
Scarring from necessary surgeries, including bariatric surgery, is assessed and combined with other impairments according to the guidelines. Assessors must also identify and deduct the proportion of impairment due to pre-existing conditions, with clear reasoning required where a pre-existing factor, such as long-standing obesity, contributed to the impairment.
Evidence and Implications for Workers
Functional narratives, including before and after weight, activity levels, medication timelines, and failed conservative measures, play a crucial role in these claims. Treating specialist opinions are vital in linking the injury to reduced mobility, pain, and subsequent weight gain, and in explaining why bariatric surgery is reasonably necessary.
Independent medical evidence should address causation to the consequential condition, not just the original injury. The PIC has criticized opinions that ignore the consequential pathway. AMA5 and guidelines-compliant impairment reports with system-specific ratings and transparent deductions are essential.
According to recent PIC decisions, “obesity/major weight gain can be compensable in NSW, not as a primary ‘injury’, but as a consequential condition flowing from an accepted work injury.”
Bariatric surgery can be funded under section 60 where reasonably necessary due to the consequential condition, and multiple PIC decisions have ordered it. WPI is assessed for the affected body systems, not for “obesity” itself, and causation and evidence are critical in documenting the chain from injury to new conditions and the need for surgery.
If post-injury weight gain is impacting your health or if your doctors have mentioned weight-loss surgery, it may be beneficial to review your medical evidence, engage the right specialists, and pursue the treatment funding and permanent impairment entitlements you may be owed under the NSW Workers Compensation scheme.
This article provides a general guide to the subject matter. Specialist advice should be sought regarding your specific circumstances.
