If he is type two diabetic he should work to reverse that, which can be done. Also, being vegetarian he should test some nutrients to see what he is deficient in. He is almost guaranteed to be lacking something. How much sunshine does he get everyday? Vitamin d is very important, which can be gotten by getting 30 minutes a day outside with as little clothing as possible. I am eating Budwig protocol, which gives a healthy Diet and can reverse diabetes. He must be vegetarian for spiritual or other reasons, because it doesn't seem to have benefitted his health. How is his prostate? That can cause erection problems also.