(י) אֲכִילַת בָּשָׂר וּשְׁתִיַּת יַיִן בְּשַׁבָּת עֹנֶג הוּא לוֹ. וְהוּא שֶׁהָיְתָה יָדוֹ מַשֶּׂגֶת.
(10) Eating meat and drinking wine is considered delight (oneg), as long as he can afford it.
תלמידי ר׳ יונה, ברכות י: (בדפי הריף)
ובשבת מיסב ואוכל בשר ושותה יין לא קאמר וחייב לאכול בשר ולשתות יין דכיון שהוא מתכוין למצוה אם ירצה יאכל ואם לא ירצה לא יאכל שאינו חובה על האדם שיאכל בשר וישתה יין בשבת
Students of R. Yonah, Berachot 10b (in the Rif)
[The Gemara says] "..and on Shabbos [a mourner who has not yet buried the deceased, and is therefore prohibited to eat meat and drink wine as an onein] eats meat and drink wine" – that does not imply that there is an obligation to eat meat or drink wine. Since this is talking about parts of the Mitzvah [of celebrating Shabbos], it includes these, as if a person wants to eat meat [as part of his Shabbat celebration] he can eat meat, and if he does not want to, he does not have to. For there is no obligation to eat meat or drink wine on Shabbat.
כתב הרב רבינו יונה ריש פרק מי שמתו (י: ד"ה ובשבת) הא דבשבת ויום טוב אוכל בשר ושותה יין היינו אם ירצה לאכול אבל אינו מחוייב לאכול בשר ולשתות יין בשבת:
(יח) ...וְהָאֲנָשִׁים אוֹכְלִין בָּשָׂר וְשׁוֹתִין יַיִן שֶׁאֵין שִׂמְחָה אֶלָּא בְּבָשָׂר וְאֵין שִׂמְחָה אֶלָּא בְּיַיִן.
(18) ...the menfolk should eat meat and drink wine, for there is no real rejoicing without the use of meat and wine.
תנו רבנן חייב אדם לשמח בניו ובני ביתו ברגל שנאמר ושמחת בחגך במה משמחם ביין רבי יהודה אומר אנשים בראוי להם ונשים בראוי להן... בזמן שבית המקדש קיים אין שמחה אלא בבשר שנאמר וזבחת שלמים ואכלת שם ושמחת לפני ה׳ אלהיך ועכשיו שאין בית המקדש קיים אין שמחה אלא ביין שנאמר ויין ישמח לבב אנוש
The Sages taught: A man is obligated to gladden his children and the members of his household on a Festival, as it is stated: “And you shall rejoice on your Festival, you, and your son, and your daughter, and your manservant, and your maidservant, and the Levite, and the stranger, and the fatherless, and the widow that are within your gates” (Deuteronomy 16:14). With what should one make them rejoice? With wine. Rabbi Yehuda says: One should enable each member of his household to rejoice with an item that pleases them, men with what is fit for them and women with what is fit for them... When the Temple is standing, rejoicing is only through the eating of sacrificial meat, as it is stated: “And you shall sacrifice peace-offerings and you shall eat there and you shall rejoice before the Lord your God” (Deuteronomy 27:7). And now that the Temple is not standing and one cannot eat sacrificial meat, he can fulfill the mitzva of rejoicing on a Festival only by drinking wine, as it is stated: “And wine that gladdens the heart of man” (Psalms 104:15).
ויש לתמוה על הרמב"ם למה הצריך שיאכלו בשר וישתו יין דהא בברייתא קתני דבזמן הזה אין שמחה אלא ביין ומשמע דביין סגי בלא בשר:
חידושי הריטב”א מסכת פסחים מט:
גמרא עם הארץ אסור לאכול בשר. פירש הרי"ט ז"ל כי מתוך עמי[ו]תו אינו יודע לשחוט ולמלוח (ולעקר) [ולנקר] כראוי.
R. Yom Tov Alshabili, Pesachim 49b
Gemara: "An ignoramus is forbidden to eat meat" - R. Yom Tov explains that this is because of his ignorance, that he doesn't know how to slaughter, salt, and clean the meat appropriately.
ואף ע"ה =עם הארץ= כזה דאמר רבי בפסחים דף מ"ט ע"ב דאסור לאכול בשר, אינו משום דכיון דהוא ע"ה לא עדיף מבהמה שיהא מותר לאוכלו, ואף שגם לבני נח כבר הותר לאכול בשר הוא מחמת שלא נצטוו בתורה וסגי להיתר אכילת בשר שהותר לנח ולזרעו במה שעדיפי שנתחייבו בז' המצות, אבל ע"ה שהוא ישראל שנצטוה בכל התורה כולה ובלמוד התורה ואינו לומד משום שלא חש לידע דיני התורה גרוע ואסרתו תורה באכילת בשר, דאף שהוא שייך לפרש כן לענין דברי אגדתא ומוסר שכל ישראל צריך להרגיש בנפשו שלא עדיף מבהמה ועוף שישפוך דמן לאכילת בשרן מאחר דאינו לומד התורה שבשביל זה נברא ומתנהג כבהמה ועוף והוא הרגש אמתי, וגם לזה נתכוין רבי
ויש שמפרשין שגם כשהבשר גלאט כשר אסור לו מצד שאין לו זכות לאכול בשר וכמו אדה"ר וכו' קודם המבול.
§ Having mentioned the prohibition against plastering, which is a sign of mourning over the destruction of the Temple, the Gemara discusses related matters. The Sages taught in a baraita (Tosefta, Sota 15:11): When the Temple was destroyed a second time, there was an increase in the number of ascetics among the Jews, whose practice was to not eat meat and to not drink wine. Rabbi Yehoshua joined them to discuss their practice. He said to them: My children, for what reason do you not eat meat and do you not drink wine? They said to him: Shall we eat meat, from which offerings are sacrificed upon the altar, and now the altar has ceased to exist? Shall we drink wine, which is poured as a libation upon the altar, and now the altar has ceased to exist? Rabbi Yehoshua said to them: If so, we will not eat bread either, since the meal-offerings that were offered upon the altar have ceased. They replied: You are correct. It is possible to subsist with produce. He said to them: We will not eat produce either, since the bringing of the first fruits have ceased. They replied: You are correct. We will no longer eat the produce of the seven species from which the first fruits were brought, as it is possible to subsist with other produce. He said to them: If so, we will not drink water, since the water libation has ceased. They were silent, as they realized that they could not survive without water.
Following the many precedents prescribed in the Code of Jewish Law, we would have little difficulty in arriving at the conclusion that, if indeed eating meat is injurious to one's health, it is not only permissible, but possibly even mandatory that we reduce our ingestion of an unhealthful product to the minimal level...
If a person tends toward vegetarianism because he sees it as a lifestyle consonant with the way that the Al-mighty really wanted the world to be, there can be no doubt that he has a valid point of view...
We may therefore conclude that when a vegetarian is loath to eat meat because he does not want to take an animal's life merely for his own pleasure, that person is acting well within the spirit of Jewish belief and philosophy. He is not denigrating a Torah value, for the Torah does not establish the eating of meat as a desirable activity, only as something that is not forbidden to do.
Now, new research published in the journal PNAS combines the two perspectives to show that the widespread adoption of vegetarian and vegan diets could save millions of lives and trillion of dollars. “There is huge potential,” says study author Marco Springmann, a researcher at Oxford University, “from a health perspective, an environmental perspective and an economic perspective, really.”
Researchers assessed four different scenarios with humans consuming varying levels of meat to evaluate the links between diet, health and the environment. The lowest level of meat consumption—widespread adoption of the vegan diet—could help avoid more than 8 million deaths by 2050, according to the study. A vegetarian diet would save 7.3 million lives.
The environmental impacts of a dietary shift could be just as dramatic, according to the researchers. Livestock alone account for more than 14% of global greenhouse gas emissions, and by 2050 the food sector could account for half if cuts are implemented in other sectors along the lines that countries have committed to doing. A vegan or vegetarian diet could cut those emissions by 70% and 63%, respectively.
Changing dietary patterns could save $1 trillion annually by preventing health care costs and lost productivity. That figure balloons to as much as $30 trillion annually when also considering the economic value of lost life. And that doesn’t even include the economic benefits of avoiding devastating extreme weather events that could result from climate change.