Less meat consumption means more protection for the environment, as the production of animal-based food consumes more resources and causes more greenhouse gases than the production of plant-based food.
Beyond ecological requirements, abstaining from meat has a long tradition.
Monk father Benedict of Nursia (around 480-547) instructed his fellow monks to abstain from animal products in his religious rules. This was or is sometimes implemented more and sometimes less.
But the monastic tradition is gaining new relevance.
In principle, the consumption of meat is not forbidden in Christianity.
The theologian Hubertus Lutterbach writes in an essay that abstaining from meat was not a fundamental part of the biblical tradition.
Accordingly, the early church did not prescribe abstaining from meat either - except before some high feasts.
In remembrance of the death of Jesus, no meat should be eaten on Fridays either.
No wine and no meat for perfection
The decisive impetus for the spread of abstinence from meat among Christians came from the church father Jerome, who died in 420.
One chapter in his first book is entitled "On the licentiousness of eating meat".
According to Lutterbach, he did not make abstinence from meat mandatory.
But at the same time, the church father emphasises: "If you want to be perfect, it is good not to drink wine and not to eat meat."
Jerome envisioned that, as in the paradisiacal beginnings of the human race, people would only feed on what the earth produces - i.e. plants.
However, the church father also assumed that meat - like wine - would lead to the "stimulation of the sexual instinct". He was therefore firmly in favour of curbing passion by abstaining from meat.
The rule had a lasting impact on monastic life. "They should never eat meat as food", it says, for example, in the rule of Aurelian of Arles (+551) for nuns. Isidore of Seville (+633) at least allows food to be prepared with animal fat on high holidays.
And the Magisterial Rule from the first half of the 6th century is relatively liberal: "From Easter to Pentecost and from the feast of the Nativity of the Lord to Epiphany, freedom is allowed with regard to the consumption of meat."
However, the meat-eating brothers must "sit separately from their tithes at their own tables" so that "the purity of the renunciates does not appear tarnished".
Monk father Benedict stipulated in the middle of the 6th century: "All, with the exception of the very weak and the sick, should abstain from the flesh of four-footed animals."
The order debated whether poultry was permitted. For Hildemar of Corbie-Civate (+850), poultry was also taboo, especially as it "tasted far more delicious than the meat of four-footed animals".
Hrabanus Maurus, on the other hand, believed that Benedict did not consider poultry to be harmful - nor did fish, which Christ himself ate after his resurrection.
Since modern times, abstaining from meat is no longer considered binding in Benedictine monasteries, as novice master Frank Möhler from Münsterschwarzach Abbey explains. "There has been a break with tradition."
Contrary to Benedict's instructions, there are no longer any shared dormitories.
"Even in the Rule itself, there has been a development towards no longer adhering absolutely to traditional ascetic customs if one is no longer convinced by them," says Fr Frank. Benedict, for example, allows the consumption of wine, although this is not traditionally appropriate for monks.
Of pumpkins and monastery tea: living and cooking in the monastery
For over 30 years, Stühlingen has had a "monastery to live in". Preparing and eating meals is an integral part of living together.
Many people have found peace in this place - and helped with the washing up.
The missionary Benedictine Aquinata Böckmann understands Benedict's guidelines today as a call to live frugally and avoid excess.
In her commentary on Benedict's rule, she refers to the current core concern of preserving creation.
In Münsterschwarzach, meat is not eaten on Wednesdays and Fridays in accordance with monastic tradition, but now also on Monday lunchtimes. When meat dishes are served, vegetarian options are also offered as an alternative.
"Less meat is also the trend in the monastery," says Father Frank.
As the operator of a butcher's shop, the abbey is also trying to counteract the "cheapening" and "commoditisation" of meat products through regional quality and its own cattle fattening.
"We want to live more sustainably"
The Benedictines in Ottobeuren receive the same food as the visitors to their guest and conference centre - which means they eat meat several times a week.
"On the other hand, our confreres are also becoming more eco- and climate-conscious, so I could well imagine reflecting more closely on the topic of nutrition in the convent," says Abbot Johannes Schaber.
The Benedictines at Maria Laach Abbey in the Eifel region eat meat-free three days a week, according to Prior Administrator Petrus Nowack.
In Kornelimünster near Aachen, the five confreres eat a vegetarian diet every day of the week.
This was suggested six years ago by a confrere who was influenced by the Catholic Young Community, says Prior Oliver.
"We want to live more sustainably."