My experience on the issue -
* Food Stat buff currently beats Drink Regen buff by a huge margin. So always use Food and never Drink.
* Don't wait until you NEED to use a potion to survive. As soon as your health drops below the point where your potion will refill you, use it. That way, it is more likely to be ready if and when you need it.
* Do be sure to use triple stat potions. The additional Sta and Mag restoration can make all the difference.
Good Hunting.