For your grandmother you can buy ensure pudding from the chemist which is absolutely delicious, usually served 3 times a day. Or instead of sustagen try twocal drinks, they actually have higher calorie content than sustagen. If money is an issue Milo made with full cream milk is just as good as sustagen.

At the place I work, the residents usally have their main meal at lunch.

Breakfast usually consists of porridge, toast, prunes and a boiled egg.
Morning tea is a small piece of cake or crackers with full cream cheese and tomato
Lunch is usually roast meat with vegies, or a pasta dish. Fridays is always Fish and chips. (its the only day everyone eats their lunch)
Afternoon tea is fruit, or a piece of cake or some yoghurt
Dinner is something small, usually a pasta bake, sausage rolls, sandwiches


My only other suggestion for you is to speak to a social worker at your local hospital and get them assessed by the Aged Care Assessment Team. They may be eligible for an aged care package, which may include someone coming around to help with house work and meals on wheels.

It will also mean that if within 12 months of the assessment being done either of them require full time care, the assessment process is already done and you dont have to waste time doing it before looking for permanent placement.

HTH