Why praying for/over the food we eat, before we eat it? Because we give thanks to God for our food and we break every curse, in Jesus' name, that can have been spoken against the food we eat. Unhealthy things can also been put into the food and when we eat it, we get infected with this and demons starts their damaging work in your body. You may don't know that food can have demons? It can, someone can ask demons to enter into the food and get into the people that eat it and the evil curses can happen. So clean the food with your words in Jesus name and thank God for your food. Read this article (That article is not made by me):
http://www.truthseekersvideo.com/articles/McDonalds_Founder_Ray_Kroc_Satanist.php God bless you and keep you safe.