All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Some scholars deemed it disliked to speak in the interval between Ash-Shaf’ (i.e. literally means paired or even-numbered) and Al-Witr (i.e. odd-numbered prayer) without a legitimate need. However they stated that Sujood as-Sahw (i.e. the prostration of forgetfulness) is not required in such a case. Ibn ‘Umar used to attend to some of his needs between the two-Rak‘ah prayer of Ash-Shaf’ and one-Rak‘ah prayer of Al-Witr (performed after the ‘Ishaa' prayer and until Fajr). It was reported on the authority of Naafi‘, the freed slave of Ibn ‘Umar that ‘Abdullaah ibn ‘Umar used to say Tasleem between (the first) two Rak‘ahs and (the third) one in the Witr prayer when he wanted to attend to a certain matter (during that interval between Ash-Shaf’ and Al-Witr). [Al-Bukhari and others]
As for eating and drinking between Ash-Shaf’ and Al-Witr prayers, one should not do so. If the scholars deemed it disliked to engage in superfluous talk in the time interval between them, then eating and drinking should be even more disliked.Allaah Knows best.