To the Editor: Australia, like many other nations, is experiencing an epidemic of overweight and obesity. The most recent National Health Survey reported that 62% of men and 45% of women were overweight or obese.1 Among numerous associated concerns is the cost burden of obesity-related illnesses on individuals, the community and the health system.

Among the 45–54-years age group (the stage at which osteoarthritis becomes a significant health problem), we calculated the population attributable risk (PAR) for osteoarthritis associated with obesity to be 25% for men and 22% for women, using a relative risk (RR) of 2.4 and obesity estimates of 23.3% for men and 20.1% for women. In terms of major health sequelae of the epidemic, this is second only to obesity-related type 2 diabetes (RR, 3.2; PAR, 34% for men, 31% for women). Some obese patients will have multiple obesity-related comorbidities.

In 2005 in Australia, 2551 national hospital separations among people aged 45–54 years were for obesity-related osteoarthritis.2 Using data from the three most recent National Health Surveys, we projected the likely prevalence of obesity among 45–54-year-old Australians in 20251,3,4 and then estimated future hospital separations and direct health system expenditure, using costing information supplied by the Australian Institute of Health and Welfare.2 We project that in 2025, if Australians born between 1971 and 1980 maintain their current rate of weight gain, the proportion of obese 45–54-year olds will rise to 38.8% of men and 32.2% of women. The estimated number of hospital separations for obesity-related osteoarthritis will increase to 4216. The direct health system cost (in current dollars) will rise to $44.4 million, from an estimated $25.5 million in 2005.

The 45–54-year-old population comprises a considerable proportion of the workforce, and obesity-related illness impacts on absenteeism5 as well as individuals’ and families’ quality of life. As the current generation of young adults ages, a trend toward increasing illness arising from high levels of obesity is likely, unless health and government policy initiatives to prevent weight gain are given higher priority.