The rhythm begins with the stronger (main, primary) stress: there are totally three syllables in each phrase and the time it takes for the first two syllable (primary stress + the weakest syllable) is almost the same as that of the last syllable (the secondary stress). That is, the pitch goes immediately down to the next syllable.
Appetite / BUY him one / HEAvily / GIVE him it / PERfectly / THInk of it / DIffer from / Dinner time /
