Shaykh Ubayd al-Jaabiri said:
It is better to delay the Suhoor meal until you come close to the Adhan of Fajr as in the hadith of Zaid ibn Thabit and Anas ibn Malik (May Allaah be pleased with them). Here, in the hadith of Anas ibn Malik, it is mentioned that the time period where the Prophet ﷺ took his Suhoor meal is between that and the actual Fajr prayer itself. And that time period was fifty verses. If one were to recite the Qur’an in the correct manner without hastiness then the time period of 50 verses will be about 20 mins or half an hour at most (to begin eating the pre-dawn meal until Fajr).