Foods That Cause Protein in Urine can worsen kidney stress when consumed in excess, especially for people with kidney disorders. A very high-protein diet, including red meat, processed meats, and protein supplements, may increase protein leakage in urine. Excess salt, packaged foods, and fast food raise blood pressure, affecting kidney filtration. Sugary foods and refined carbs can worsen diabetes-related kidney issues. Limiting these foods supports healthier kidney function.