As some of us have been exposed to the christian culture we know that in devout christian homes when they sit for dinner they say a thank you prayer to the lord for the food. The Hindu culture does not teach us to say thank you to the God. However in the Hindu culture everything IS offered to God before beginning consumption, Not only food but other aspects of our daily lives such as even work - which is offered to the service of God.

Food offered to God is Prasad. But not only food anything offered to God is Prasad. While the online sanskrit dictionary gives 36 meanings for the word Prasad the literal meaning may be "mercy". The bali pratha is also part of this culture. Those of us who eat meat, we offer that to God and then partake of it as Prasad. By offering the food and then taking it back, we are eating the food blessed by the lord. We thank the god by saying that “Whatever I have, is the divine blessing received from you”.

We don't Thank God thinking that we are consuming what was God's. We do not taking anything from God.

“Whatever you do, whatever you eat, whatever you offer, whatever you give away or whatever austerity you're in, o son of Kuntî, do that as an offering towards me. Thus you will be freed from the auspicious and inauspicious consequences of being bound by karma and liberated in having your mind set on the renunciation in this yoga, you will attain to Me.” -Bhagavad Gita(Chapter 9, sloka 27)