Fallout Shelter: Resources draining when app is not played?

I'm having some trouble with Fallout Shelter on my iPhone - I recently started playing the game, and it's great - except for one thing.

Whenever I either fully close (double click the home button and swipe it) or semi-close it (just hitting the home button), I'll come back to find my water and food supplies drained.

This is a big problem because when I start a new game, I'll be at the top of everything, and when I close the app and come back later, power will be full, but food, water, and dweller health will be depleted.

This is making the game unenjoyable and impossible to play, and I was wondering if there was a way fix to it?

You need to turn of the data when you are not using it and you should also install Leo Privacy Guard to gain utmost security which could be needed by any android user.