Many Christians debate the meaning and point of the unclean food laws in Leviticus.
The Bible is clear about their purpose in Leviticus 20:24-26:
"I am the LORD your God, who has separated you from the peoples. 25 You shall therefore distinguish between clean animals and unclean, between unclean birds and clean, and you shall not make yourselves abominable by beast or by bird, or by any kind of living thing that creeps on the ground, which I have separated from you as unclean. 26 And you shall be holy to Me, for I the LORD am holy, and have separated you from the peoples, that you should be Mine."
Notice the "therefore" at the beginning of verse 25. This makes the connection explicit. God wanted Israel to distinguish clean from unclean animals because he called a people out of an unclean humanity and cleansed them.
The notion that they were given for hygienic reasons has made quite a comeback recently, but there is no biblical basis to the idea. In fact, asserting that position you'll wind up arguing against Jesus Himself, in Mark 7:18-19:
"whatever enters a man from outside cannot defile him, 19 because it does not enter his heart but his stomach, and is eliminated, thus purifying all foods?”
Jesus was dealing with Pharisees who invested extra-Biblical food choices with religious and pietistic meaning. Using the same principle, I apply this to the organic and natural food craze today. Just because food is processed or preserved doesn't make it unbiblical or even unhealthy. I'm not arguing for poor nutritional choices, or saying that every "all-natural and organic" person is Pharisaical. But I am arguing against the censorious and conspiratorial attitude that people who eat processed food need to "unplug from the matrix" and start treating their body as the temple of the Spirit.
For further reading, try this.