So there is a glitch where when you put some food or a canteen/water bottle in hands and scroll down , if you chose the Eat all/Drink all option and then press X and the F , a message will appear saying that you have cancelled the action but you will still consume/drink it all . The food/water will still be in your inventory (fully/depends if you open it with an can opener) but you will get energized / hydrated . So you can actualy have a can of peaches and a canteen and you can eat and drink as much as you like .