Uki, my first thought was "pregnant", of course, but as I read further, you dispelled that notion!
That is weird that your appetite has changed! I would just do "bland" sort of stuff until you bounce back completely. Still try to get in your requirements, then you will probably be "ravenous" in a few days for everything you haven't had lately!
Sometimes, it takes several days or a week to get back to "normal". Just go with the flow for now and be sure and keep up your strength!
I get like this where nothing sounds appealing after the flu. Might take you couple more days before your appetite returns.
When I was a kid, I came down with the flu at my grandmas's house and I vividly remember puking up orange Kool Aid. To this day, I despise just about everything orange flavored..that includes candy, soda, popsicles, orange juice.
My sister was like this with Pizza Hut pizza. She will not eat pizza from there, but everywhere else is ok....weird huh? LOL.