Narrated from Anas (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) forbade drinking while standing. It was asked: What about eating while standing? He said: "That is even worse." Imam Tirmidhi says:
This hadith is Hasan Sahih.

'Abdullah bin Umar (may Allah be pleased with them both) says: "In the time of the Messenger of Allah (peace and blessings of Allah be upon him), we used to eat while walking and drink while standing." 1. Imam Tirmidhi says:
1- This hadith is sahih ghareeb through the chain of «عبيد الله بن عمر عن نافع عن ابن عمر» ,
2- Imran bin Hudeir narrated this hadith from Abu'l-Bazra from Ibn Umar (may Allah be pleased with them both),
3- Abu'l-Bazra's name is Yazid bin Atard.