Wherever you travel it is possible to get most food for your expedition on arrival. If you have employed a local agent they are likely to have bought this before you get there, but if working alone stock up in a large town or city as availability may diminish markedly once you reach more remote locations.
Two major exceptions are lightweight, dehydrated mountain foods and dehydrated soups. You would be well advised to bring these from the UK unless you are happy to live on noodles and dehydrated potato. Remember that unprepared rice does not cook at altitudes unless you have a pressure cooker!
Since you are likely to be working on an energy deficient diet, high energy foods are desirable if you do not wish to return emaciated. One company, Expedition Foods, supplies a variety of high energy (800Kcal) meals and offers a 10% discount to AC members, but many other brands are available.