Ramadan · a Light

The meal before dawn was made a practice on purpose

The Prophet ﷺ told his companions to eat before dawn, because in that meal there is blessing. He also kept the gap between the end of it and the call to prayer short. Zayd ibn Thabit said they ate with him and then stood for prayer, and when Anas asked how long the interval had been, Zayd measured it as the time it takes to recite about fifty verses. A fast kept without the pre dawn meal is still valid. It is the practice, not the fast, that the instruction protects, and the reason given is not medical but a blessing placed in the act of getting up in the dark to eat with your household.

Anas and Zayd ibn Thabit · Ramadan

Source · Bukhari 1923, Muslim 1095