Carrying extra weight can lead to worn-out joints such as hips and knees, according to a Canadian report.
The Canadian Joint Replacement Registry (CJRR) survey of more than 17,244 total hip and knee replacements performed in 2004, found 46 per cent of patients were obese, compared with 23 per cent for the whole population.
Obesity participants were classified as having a body mass index (BMI) of at least 30.
When patients who were overweight but not obese (BMI 25 to 29.9) were added to the totals 72 per cent of people receiving hip replacements and 87 per cent receiving knee replacements were overweight.
Patient UK said one of the most common reasons for joint replacement is osteoarthritis caused by pressure on joints.
This can be made worse by age and by carrying extra weight.