For knee health, nutrition strengthens the supporting system (muscle and bone) rather than the joint surface alone. First: adequate protein to build quadriceps and hip strength—stronger muscles reduce knee load. Second: weight management—excess body weight increases knee forces, so balanced calories and high nutrient density matter. Third: inflammation control—omega-3 (fatty fish), fruit/vegetable-forward eating, and reducing ultra-processed/high-sugar loads. Fourth: bone infrastructure—adequate calcium plus vitamin D supports the surrounding bone. Fifth: hydration and micronutrients like magnesium and zinc matter when deficiencies exist. Nutrition alone is not enough; the most effective knee “strengthener” is targeted exercise (resistance training, balance, mobility). If you have swelling, locking, post-injury pain, or prolonged morning stiffness, seek orthopedic/rheumatologic evaluation.