In our personal experience, Tom's goal of 2500 cal. and 64 oz of water is impossible. My husband's stomach can not tolerate that amount of "imput", so he is on a feeding tube nutrient that has 475 cal. per can [it also comes in a drinkable form] The best he can do is 4 of those, plus water and Gatoraide in a 24 hr. period. Sometimes we can sneak in an extra 8 oz. of bullion or thinned cream soup to boost the caloric intake some. The main thing is how often does your Dad want to try to eat and how much can he tolerate at a given time? If you can get that schedule worked out, then you can start working on the most calories possible at each meal. It's a challange. Best Luck. Amy