He who regards one day as special, does so to the Lord. He who eats meat, eats to the Lord, for he gives thanks to God; and he who abstains, does so to the Lord and gives thanks to God.
It is no surprise that we are to give thanks for the food that we eat. But Paul instructs that those who abstain from eating also give thanks.
The issue Paul addresses is eating meat that had been sacrificed to an idol. Some saw this as an endorsement of idolatry while others viewed the idol as nothing and therefore meat that had been sacrificed to it was no different than regular meat.
A more modern situation would be vegetarians. The same solution can be offered. From a biblical standpoint, whatever we eat should be eaten with thanksgiving. Those who have determined to eat something should do so with thanksgiving and those who have determined to abstain should do so with thanksgiving.
God has given us all things but not all things are beneficial according to 1 Corinthians 6. It is for us to determine what is and isn’t beneficial according to guidelines in the Bible. For instance we are not to be mastered by anything and thus drugs are not beneficial.
Whatever we choose to do and whatever we choose to put into our bodies, we are to do so with thanksgiving. Whatever we receive from the Lord, we should do so with thanksgiving.