According to one of the Talmudic sages, Adam was forbidden to eat meat.
His students were puzzled: It is related that Adam would sit in the Garden of Eden and the heavenly host would roast meat for him and serve him wine. This means that Adam did eat meat.
The sages answered that Adam was permitted to eat meat which came from the heavens, such as the meat which the heavenly host roasted, but the meat of any animal which grew upon the earth was forbidden.
The students continued and asked: is it possible that meat descends from the heavens? Immediately the answer was given: yes!!! An incident in which this occurred is related:
Rabbi Simeon the son of Halafta was walking and met lions who roared for prey. He prayed for assistance and two animal thighs fell from the heavens. The rabbi left on thigh for the lions and took the other to the study hall to ask whether one is permitted to eat a thigh which fell form the heavens. They told him it is permitted, for nothing which is impure falls from the heavens.
A different sage asked: What is the rule if meat in the form of a donkey falls from the heavens? They answered him: You fool! Nothing impure falls from the heavens, so meat in the form of a donkey would not fall. If it did in any case fall in the form of a donkey, it would be permissible.
(Babylonian Talmud, Tractate Sanhedrin 59b)
The Talmudic text:
Rav Yehudah said in Rav’s name: Adam was not permitted to eat flesh, for it is written. An objection is raised: Rabbi Yehudah the son of Tema said: Adam reclined in the Garden of Eden, while the ministering angels roasted flesh and strained wine for him. Thereupon the serpent looked in, saw his glory, and became envious of him!! The reference there is to flesh that descended from heaven. But does flesh descend from heaven? Yes; as in the story of Rabbi Simeon the son of Halafta, who was walking on the road, when lions met him and roared at him. Thereupon he quoted (Psalms 104): The young lions roar after their prey; and two lumps of flesh descended. They ate one and left the other. This he brought to the schoolhouse and propounded: Is this fit for food or not? The scholars answered: Nothing unclean descends from heaven. Rabbi Zera asked Rabbi Abbahu: What if something in the shape of an ass were to descend? He replied: You howling jackal: did they not answer him that no unclean thing descends from heaven?