The amount of food depends on the chosen track. You know the best approximately how many kilometers you are able to fly in mountains in a day. I would like to recommend you to create a track for 2-3 days and takeoff when you’ll know that the weather will stay the same these days. Waiting somewhere in mountains after one flying day for good conditions again is really doubtful and a risk of problems grows. For 2-3 days you need some tea, some dried food (just to pour the meal with a hot water) and nuts. These foods have a high ratio of an energy and weight. Powder milk for babies (Sunar) is also very nutritious. If you plan a longer flying trip don’t forget on vitamins and water purifier tablets. Not in every mountain streamlet is good clean water. If above your camping place are some grazing lands with sheep or cows, I would change my mind to drink this water.