My Dear Freind, As you mentioned that your father has lost lot of weight , that is a clear sign that his blood sugar levels are not properly regulated and he needs to be seen by a diabetologist. So before bothering about the diet, you must treat the root cause, that is uncontrolled diabetes. I am outlining a simple diet plan, it is for 24 hours ( three major and one small meal). 1. 50% of total intake of food must comprise of salads, sprouts, vegetable and some fruits. 2. 25% must be carbohydrates, that is wheat and rice in any form. 3. The remaining 25% must be protiens, that is soya paneer (tofu), protien powders, mushrooms, nuts of all kind. If your father eats non veg, then he can have egg white, fish and chicken. Meat must be avoided, but he can have it once in a while. I pray for good health of your father. Regards Dr. Anamay Kamalakar Bidwai Chennai