White foam in urine after meals may be caused by diabetes, kidney function damage, urinary tract infection and other reasons. 1. diabetes: diabetic patients due to elevated blood sugar, the sugar in their urine increases, which can cause the surface tension of urine to become larger, easy to form white foam. 2. Renal function impairment: it may be due to renal function impairment caused by nephritis, nephrotic syndrome, hypertension and other disease lesions. It can affect the semi-permeable membrane of the glomerulus, which makes the semi-permeable membrane degenerate, causing the increase of urinary protein and the surface tension of urine to become larger, thus forming a white foam. 3. Urinary tract infection: it may be caused by a variety of pathogenic bacteria, due to the stimulation of inflammation, the mucosal epithelium of the urinary tract will be in a highly congested and edematous state. The highly swollen urinary tract epithelium is easy to shed, coupled with the bacteria in the urine, the two together after the urine can become cloudy, thus appearing white foam phenomenon. Patients who have white foam in the urine after meals should go to the hospital in time to find out the cause and follow the doctor’s instructions for treatment to avoid delaying the condition.