Praise be to Allah, and may His Peace and blessings be upon Prophet Mohammad.
It is impermissible to eat, or drink after the second Athaan of dawn prayer is called, for Allah, The Almighty, says in this regard: “and eat and drink, until the white thread of dawn appear to you distinct from its black thread.” {Al-Baqarah/187}. The Prophet also said in this regard: "Bilal pronounces 'Adhan at night, so keep on eating and drinking (Suhur) till Ibn Um Maktum pronounces Adhan." {Bukhari}. This is because Ibn Um Maktum called for prayer at the break of dawn, and this is unanimously agreed upon among Muslims. As for the Hadith: “If any of you hear the call for dawn prayer while holding a dish to drink from, he/she should put it aside only after having taken what they needed.” {Abu Da`wood}, In [E`llal Ibn Abi Hatim 340/759]),
Abi Hatim (May Allah be pleased with him) said: "This Hadith isn`t Sahih (authentic. Ibn Al-Qat`tan) said there is doubt that the Prophet (PBUH) had said the above Hadith". [Byaan Al-Wahim Wa Al-Eihaam2/282].
If the aforesaid Hadith was sound, then the Muslim scholars must have interpreted it as pertaining to the Athaan about which there is doubt regarding the break of dawn.
In another opinion for the Muslim scholars, the Hadith was interpreted as indicative of the first Athaan which is called at night, and not at dawn. As for the second Athaan (dawn break), neither eating nor drinking is permissible after it.
Therefore, one who ate, or drank after the second Athaan, should refrain from eating and drinking for the rest of that day, and should make up for it after Ramadan because the start of the Athaan indicates the break of dawn. However, if he/she had done so intentionally, then they are sinful, and in addition to refraining from food and drink for the rest of that day, and making up for it later, they are obliged to seek sincere repentance along with showing remorse and determination not to commit that sin again. They should also make a lot of Istighfar (seeking Allah`s forgiveness).
Consequently, a Muslim should follow the opinions of the majority of the Muslim scholars as far as religious affairs are concerned.