When you are hungry or thirsty, you imagine that it is merely your body that desires to be refreshed.  The Ba’al Shem Tov taught that your soul yearns for the food too.  In every piece of food or drink there are holy sparks that have been lost since the beginning of time.  Your soul is pining to elevate those sparks back to God, by eating the food with this thought in mind.  ~ R’ Chaim Miller