Feed once or twice a day?

i have a mini poodle and when he was a baby i was feeding him once a day and now that he is an adult now he jsut turned 1 jan 4, on the blue buffalo bag it says to feed only once a day. im trying my best to do only once a day but he start to whine and jump against the cabinet in the kitchen cuz hes hungry so i give him a 2nd meal. how do i convert from 2 to 1 meal a day?