Hello, Welcome to Health Care Magic. I read carefully your query and I understand your concern The guide to the diet of your father is based on the renal failure, the dialysis and the fact that is a diabetic patient. I will recommend in general way what to eat and avoid but a renal dietitian explain you in more detail. As you mentioned here, the first to know is how water can your father drink, your father should know that in this condition he need to monitor the liquids intake, he should avoid water, liquid foods like soup, fruit and vegetables that contain water e.g. melons, watermelon, tomatoes etc. He should control the thirst by avoiding of salty foods; he should take low-sodium foods. Foods to avoid or eat in small portion are rich potassium foods e.g. bananas, plums, potatoes, apricots, dried foods etc .Recommendable to low the potassium is to boil the potatoes. He should avoid high-phosphorus to avoid bone problems and skin itch e.g. milk, cheese, nuts, peanuts. For proteins he should eat high-quality proteins that come from meat, fish, poultry and eggs. He can eat vitamins recommendable from your doctor like: Nephrocaps. Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. I will be happy to answer your questions. Kind regard, Dr .Marsida Janko