Sorry to Majalis if I'm overstepping my bounds here by stating this considering it's kind of cheating, but if you're really desperate to extend your gameplay as of now, you can also edit the save file using a text editor such as Notepad++ to give you some more food. Regular Notepad should work too, but I haven't tested this personally.
Find the save.json file in the "data" folder and open it with your text editor. Then hit CTRL+F on your keyboard to run a word search and type in "food" to find the line showing the amount of food you carry and edit the number it shows (just don't accidentally delete the comma proceeding the number by mistake, that could break the save file and the game may not be able to load it). Don't put a number in that nuts or extremely high: something like 500 seems to work just fine in my tests and doesn't break the UI in anyway or seem to cause glitching anywhere that I saw.
Unless you know exactly what you are doing and how to do it, I wouldn't recommend changing anything else as these sort of save files will only work when they are set up, formatted, and structured a particular and exact way. Any missing or improperly placed characters, lines, spacing, etc. will invalidate the file and render it useless unless those errors are corrected manually. Even then it might not fix the issue. Even a number value too high or too low can muck it up. Backing up your save is highly recommended if you insist on editing the file either way.