Weight loss: the treatment of choice for knee osteoarthritis? A randomized trial

SummaryObjectiveWe wanted to assess the effect of rapid diet-induced weight loss on the function of obese, knee osteoarthritis (OA) patients.MethodsEighty patients with knee OA, 89% women (n=71), were recruited. Mean (SD) body-mass index (BMI) was 35.9 (5.1) kg/m2 and age 62.6 (11.1) years. Patients were randomized to either a low-energy diet (LED 3.4MJ/day), or a control diet (5MJ/day). The LED group had weekly dietary sessions, whereas the control group was given a booklet describing weight loss practices. Changes in body weight and body composition were examined as independent predictors of changes in knee OA symptoms. Symptoms were monitored by the Western Ontario and McMaster Universities' (WOMAC) OA index.ResultsThe LED and control group lost a mean (SE) of 11.1 (0.6)% and 4.3 (0.6)%, respectively, with a mean difference being 6.8% (95% confidence interval (CI): 5.5 to 8.1%; P<0.0001). The decrease in body fat percent was higher in the LED group, 2.2% (1.5 to 3.0%; P<0.0001). The total WOMAC index improved in the LED group (P