Study Summary

Nine randomized controlled trials including 898 patients with osteoarthritis were included in this systematic review and meta-analysis comparing dietary interventions (reduced energy, Mediterranean, low-fat, anti-inflammatory, low-carbohydrate, and plant-based diets) versus usual care or alternative dietary approaches. Pooled outcomes of interest included pain, physical function, and body weight. Dietary interventions significantly improved pain (SMD −0.67, 95% CI −1.01 to −0.34; p < 0.0001), physical function (SMD −0.62, 95% CI −0.94 to −0.30; p = 0.0001), and body weight (MD −3.18 kg, 95% CI −3.52 to −2.83; p < 0.0001). Reduced energy diets demonstrated the largest and most consistent benefits across outcomes, while Mediterranean diets did not show significant improvements in pain or physical function. Overall, these findings suggest dietary interventions—particularly reduced energy diets—play a meaningful role in osteoarthritis management.