ok 4lbs... so i'd say give him 1/4 c of food in the am and 1/4 c food in the pm... and let's imagine that each feeding is out of 100 parts... make 30 parts the meat (do you KNOW how much protien he shoudl get a day?? i don't know much about low protien diets) 50 parts veggies 20 parts starch... and you dont' need a scale.. just go out and buy some meat
see how long it lasts.. you can make it up and then freeze it