get up an appetite
Fig. to do something to make one very hungry. (Usually in this order.) He can't seem to get up an appetite these days. Whenever I jog, I really get up an appetite.
have an appetite for something
1. Lit. to have a desire to eat something in particular. I have an appetite for a nice big steak.
2. Fig. to have a desire to have, see, hear, etc., something. Bobby has a big appetite for sports and activity. Bob has no appetite for violence on television.
lose one's appetite
to lose one's desire to eat. After that gory movie, I'm afraid I've lost my appetite.
whet someone's appetite
Fig. to cause someone to be interested in something and to be eager to have, know, learn, etc., more about it. Seeing that film really whetted my sister's appetite for horror films. She now sees as many as possible. My appetite for theater was whetted when I was very young.