In 605 B.C. Jerusalem was conquered by the Babylonians and many of their best young men were taken into captivity, including Daniel. Daniel was taken to Babylon to serve it. As Powerful King, Nebuchadnezzar. Daniel as an example of boldness and faithfulness to God in the most difficult circumstances had eternal impact on the people and the kings that he encountered.
Note : While the Jews were subject to various food laws, forbidding to eat several types of food (e.g. pork), the Christian is under no such restriction today.
Note the following texts: Matthew 15:17-20 , Mark 7:15-19, 1 Timothy 4:1-5