We have a very descriptive word for a periodic drunkard in German: Quartalssäufer. I think that Henry has a similar problem.
He can go a day or two turning his nose up on wet food he has relished before only to wake me on day three with determined headbutts and then proceed to devour a whole tin with lots of slurping and smacking his lips. (Question to self: Do cats smack their lips?)
There are two possibilies: He might be a Quartalsfresser, i.e. a periodic glutton.
I tend to believe the alternative: He just loves messing with me.