Is it possible my metabolism has increased after lip injections or am I crazy?

My assumption is that you must have been a bit stressed or nervous about the procedure which kicked in some adrenaline and made you hungry immediately after. It's our own body's response to stress or angst. Not the fillers or Botox themselves. "This
answer has been solicited without seeing this patient and cannot be
held as true medical advice, but only opinion. Seek in-person treatment
with a trained medical professional for appropriate care."