>>> "if I bring my food in my checked luggage,"
---- We bring lots of food every year. Just pack it in ckecked luggage and leave in its original boxes/packages.
>>> "are the clear bags just for liquids put in the carry on bags?"
---- Correct! Actually I think its only one quart size clear bag per person and you don't put it in the carry-on but place the bag in the same box with your shoes, keys, watch, ......
That Web Site above gives all the details.