[anonymous]

Sudden changes in appetite and behavior are often red flags that something is wrong.
When she goes to the vet for her annual exam, lab work and dental check, bring up your concerns.

Or take her the vet sooner if you are really concerned. I would do that, before changing her diet. Always rule out medical causes first.
BTW: There are no veterinarians affiliated with DFA. So all comments should be regarded as opinion.
Good luck.