Cat suddenly eating more?

[Thurlow]

Dcat is 4 and has always seemed in great health. We've had her for a year and she's always had slight issues with food, we assumed did to not being fed at her previous home. She ate a lot to get her weight up and recently the nurse recommended we cut her food slightly so she stopped gaining weight as she was just about to creep into being overweight.

I've not even managed to do that as she's suddenly started being ravenous. She is just under 4kg and has two wet sachets and a handful of dried a day. She has started begging constantly for food, yowling and scratching at the cupboard, trying to break in to the cupboard, getting into the bin if she can smell a sachet in there.

I think she might have lost a little weight too.

I'm going to make a vets appt this week, but is she likely to be poorly?