No, kidney disease isn't caused by too much protein from diet. A healthy kidney is like a filter, it filters the protein in the blood, forbid much of them going to the urine. In a kidney disease, the filter is less functional, it allows proteins going to the urine, that's how the protein in the urine goes up. In a word, the protein was always in your body, when the kidney is healthy, the protein is in the blood, when the kidney isn't healthy, some protein goes to the urine from the blood.