My RB-cat used to do that too !!!
He was fed regularly !! He was always asking for more food ; I had to step over to a diet , as he was gaining to much weight , and this was no good for him !! He was suffering from a heart-disease , and was sleeping most of the day .
So , when feeding time came up , he scrunched it all up in a second ... ! Lots of times this resulted in throwing it all back up after a few minutes ... ! So the message from the vet was : feed him everytime he beggs for it , but give very small portions , so he won't get to much food !! This helped a lot !!
Unfortunately , dear Sydney passed away a month ago , while we were on vacation , from a heart-attack ..........! Poor Sydney ...