Daniel 1:8-20 Daniel had a vegetarian diet

⁸ But Daniel purposed in his heart that he would not defile himself with the portion of the king's meat, nor with the wine which he drank: therefore he requested of the prince of the eunuchs that he might not defile himself.

⁹ Now God had brought Daniel into favour and tender love with the prince of the eunuchs.

¹⁰ And the prince of the eunuchs said unto Daniel, I fear my lord the king, who hath appointed your meat and your drink: for why should he see your faces worse liking than the children which are of your sort? then shall ye make me endanger my head to the king.

¹¹ Then said Daniel to Melzar, whom the prince of the eunuchs had set over Daniel, Hananiah, Mishael, and Azariah,

¹² Prove thy servants, I beseech thee, ten days; and let them give us pulse to eat, and water to drink.

¹³ Then let our countenances be looked upon before thee, and the countenance of the children that eat of the portion of the king's meat: and as thou seest, deal with thy servants.

¹⁴ So he consented to them in this matter, and proved them ten days.

¹⁵ And at the end of ten days their countenances appeared fairer and fatter in flesh than all the children which did eat the portion of the king's meat.

¹⁶ Thus Melzar took away the portion of their meat, and the wine that they should drink; and gave them pulse.

¹⁷ As for these four children, God gave them knowledge and skill in all learning and wisdom: and Daniel had understanding in all visions and dreams.

¹⁸ Now at the end of the days that the king had said he should bring them in, then the prince of the eunuchs brought them in before Nebuchadnezzar.

¹⁹ And the king communed with them; and among them all was found none like Daniel, Hananiah, Mishael, and Azariah: therefore stood they before the king.

²⁰ And in all matters of wisdom and understanding, that the king enquired of them, he found them ten times better than all the magicians and astrologers that were in all his realm.

-Daniel 1:8-20 King James Version (KJV)

The prophet Daniel appears to have been a vegetarian because pulse is herbs or vegetable food in general. The wine he did not wish to drink was probably fermented wine however even if it was unfermented wine it is still better to drink water as this would have a high sugar content.

Arcana Coelestia, by Emanuel Swedenborg, [1749-56], tr. by John F. Potts [1905-10], at sacred-texts.com

1002.

...Eating the flesh of animals, regarded in itself, is something profane, for in the most ancient time they never ate the flesh of any beast or bird, but only seeds, especially bread made from wheat, also the fruit of trees, vegetables, various milks and what was made from them, such as various butters. To kill animals and eat their flesh was to them a wickedness... They took from them only service and use, as is evident from Genesis 1:29-30. But in process of time, when men began to be as fierce as wild beasts, and even fiercer, they then for the first time began to kill animals and eat their flesh; and because such was man's nature, it was permitted him to do this, and is still permitted, to this day; and so far as he does it from conscience, so far it is lawful for him, since his conscience is formed of all that he supposes to be true and thus lawful. No one therefore is at this day [1749-56] condemned because of eating flesh.

The Ascended Master Saint Germain teaches us why the Ascended Masters, including Beloved Jesus, Who dwell permanently in the Celestial Kingdom of Heaven and therefore know the Celestial Laws there, do not eat meat and why we should not eat meat either: There is a definite reason why We never eat meat, and why human beings should not eat it either. This is because the atoms of which it is composed are the condensation into substance of this world of mankind’s own vicious thoughts and feelings of the past. (The Magic Presence by Godre Ray King p149) The Beloved Goddess of Light teaches: A person who continues to use intoxicants, tobacco, meat and all those things which bring depravity upon mankind, is not a [real I AM] student and never will be so long as that one continues to do such things! (The Voice of the I AM 1940 February p11)