Salam, Awad.

Thank you for your question.

As for the prohibition of food I quote below one relevant Quranic verse which gives the meaning of:

*{Forbidden to you (for food) are dead meat, blood, the flesh of swine, and that on which has been invoked the name of other than Allah; that which has been killed by strangling, or by a violent blow, or by a headlong fall, or by being gored to death; that which hath been (partly) eaten by a wild animal; unless ye are able to slaughter it (in due form); that which is sacrificed on stone (altars); (forbidden) also is the division (of meat) by raffling with arrows: that is impiety...}* (Al-Ma'ida 5:3)

Your doubt is why God should prohibit any kind of food, while God is the One who has created everything. Well, everything has a purpose in God's scheme. If God tells His obedient servants (that is to say, those humans whom are willing to follow His laws) that they are prohibited from eating a particular kind of food, then the duty of His servants is just to follow that command.

That is a test from God, which those who love God follow literally. It is not a question of certain things having been created by someone other than God. God is the Creator of everything. God is in command of everything. God is the Lawmaker and the Lawgiver; He has the Dominion and the Power of command.

This is the Islamic view of the universe and our duty is to understand His commands and obey. It is a matter of submitting to his Will, not a matter of who created what is prohibited and who did not.

I hope this brief answer gives you an idea about the wisdom of yielding to the only One Who is worth surrendering to in complete submission.

I hope this answers your question. Please keep in touch.

Salam.

Useful Links:

The Logic of the Lawful and the Unlawful

The Purpose of Life

Man... Vision and Mission

Why Did Allah Create Us?

Why Did Allah Create Humans?

Does God Need to Be Worshipped?