Lots of soup, that being the most resource efficient way of feeding large numbers of troops since inmemorial time. Simply boil everything you have, meat, vegetables, flour..etc on big vats.
This is from memory as my library is at present packed in cardboard boxes after I've entered an institution.
but I swear everything I write I have seen printed in black and white in some book here and there.
To begin with, you should look up what were the daily rations for troops in combat of each nation. These appear in a couple Osprey books of the Warrior series, like German
Stormtrooper ,
Italian Arditi French Poilu and
British Tommy 1914-18books. Generally speaking, soldiers in the Great War were not well fed, even for the British that had the better supply situation, the staples of the diet were canned or preserved meat, biscuit (hard tack, really), and bread, with little on the way of fresh meat, vegetables or fruits. The Germans due to the blockade were the worse off, with rations being reduced each year, 1916 had the dreadful "turnip winter" due to the failure of the potato crop, in 1917 a meatless day a week was introduced, and by 1918 they were on the verge of starvation, I think it was Ludendorff that remarked German troops were
"worse fed than a chinese coolie"
But some of the Allied armies had their problems as well, the lousy quality and quantity of the food was one of the causes of the French mutinies of 1917, and in the Italian army, better rations were a very powerful incentive to join the
Arditi shock troops.
So the daily rations for frontline infantry would be a good baseline. Pilots of course had it better than the poor bloody infantry since they could count on regular meals served hot, and since airfields were to the rear, the surrounding countryside offered more opportunities for bartering or buying from the local peasants, or plain foraging, euphemism for looting for food.
Since a lot of pilots were officers, they naturally would get better rations than the rank and file.
Also, since airmen had a hazardous duty, they probably got better rations, on par or better than those of shock troops. For example, in the Second World War, German U-boat crews had the best rations of the Wehrmacht, followed closely by fighter pilots, I think.
Now, back to the Great War, zeppelin crews did get the luxury of hearty breakfasts with eggs and bacon and other stuff, a high calory intake meal, before sailing out on a raid. That was a neccessity, since they had to endure several hours of flight at artic temperatures at high altitude.
I believe pilots were comparatively well fed, but they weren't certainly feasting on lobsters and champagne like at a general HQ table.And German pilots were the worse in this regard. I recall reading that even
Manfred von Richthofen status and glory didn't secure him three hot meals a day of whatever he liked and sometimes
"he was grumpy because there wasn't good things to eat"
Also, in a very good and detailed, autobiographical novel called
"In the line" , the author, who was a German infantryman in the trenches, fed up with eating turnip puree, goes to visit a fighter pilot friend of his, in the winter of 1917-18 hoping to take advantage of the supposed delicatessen available to aviators, and all he had to eat was pickled tripe and artificial honey.
And since this has made me hungry and is dinner time, I will log off now.