The food group of SSC has submitted two motions to VSETH to promote sustainable and more plant-based catering at ETH. Below we present some arguments for our proposal, but you can read the text of the motion and how we got to them here.
A thousand years ago, less than 4% of habitable land was used for farming. Today it's 44%. Only a quarter grows food eaten directly by people, while 70% supports livestock that provide just 38% of global protein and 17% of calories. If everyone ate a vegan diet, farmland use could fall by 75%, freeing an area equal to North America and Brazil combined. Agriculture also consumes about 70% of global freshwater, with animal products requiring far more resources.
The global food system is responsible for around one third of worldwide greenhouse gas emissions. Most come from land-use change and livestock. Research from Oxford University shows that switching to a fully plant-based diet could cut food-related emissions by up to 73%.
Extensive land use for grazing and feed crops is a major cause of deforestation and species loss. Today, 70% of all bird biomass consists of domestic birds. Among mammals, livestock make up 62%, humans 34%, and only 4%, from mice to whales, are wild.
While it's true that meat-substitute products can cost more than meat, designing a plant-based diet intentionally can reduce costs. The Bryant report (2024) gives an example of this, estimating that plant-based meals are on average “on average 30% cheaper than meat-based meals, and 21% cheaper than vegetarian meals”. We can understand this intuitively: plant-based food is simply cheaper to produce, animal products are only kept afloat by large government subsidies. Thus, plant-based can prevent further cost increases in the ETH mensas.
As climate change starts impacting everyday life more and more, the need to adapt will become increasingly pressing. Plant-based food is one part of the picture and we can stay ahead of the curve by supporting this transition. The ETH spin-off Planted focusing on meat substitutes is one of many Swiss start-ups in this space, but other technologies like precision fermentation, vegan dairy or cultured meat are promising as well.
Whether in Zürich or abroad, fully plant-based mensas already exist and thrive. Furthermore, many canteens choose to increase the ratio of plant-based food in their meals. While the plant-based model is far from ubiquitous due to cultural reasons, it is demonstrably viable and gaining ground every year.
Among all the existing sources of dietary proteins, plant-based sources dominate the supply of proteins with 57 %. And for a good reason: even animal proteins ultimately come from a plant source.
The 9 essential amino acids can be obtained from combined out of different plant-based meals a day. Nonetheless there are plant foods like soy and quinoa that contain all essential amino acids by themselves.
Evidence indicates that plant-based dietary patterns are associated with health and environmental benefits. Even many athletes prefer a plant-based diet and achieve good results thanks to it. Plant-based diets can lower risk of chronic diseases, cancers, and asthma. They also support healthy weight and gut microbiome.
Plant-based diets were consistently associated with a lower incidence of allergic sensitization and reduced symptom severity. Of course, mensas still need to communicate with students and make sure nobody is left behind.
Out of the most common food allergies, lactose, egg and fish are not relevant as plant-based meals do not contain them naturally. However nut and gluten allergies must be considered.
While phytoestrogens, in this case isoflavones in soy, are structurally similar to estradiol, and can indeed interact with the endocrine systems of some animals, their effects on humans are inconsistent, as they can have both estrogenic and anti-estrogenic activities. The limited scientific evidence we have generally links intake of isoflavones with positive outcomes in humans. In the case of soy milk, the often proposed alternative, cow's milk, can contain high levels of mammalian hormones such as estradiol in significant amounts (especially when produced by a pregnant cow, which is common practice in industrial farming), which makes the argument against soy milk even weaker.
Basic microeconomics principles can explain this well. For the sake of food security, governments engage in subsidies and deliberately create an oversupply of agricultural products. Thus, particularly some durable dairy products (e.g. milk powder) can be cheap in a way that doesn't reflect the production costs. It is also often cheaper to use existing supply lines and infrastructure. This explains why the cost function might favor continuing to use animal based ingredients in some cases. Another avenue of analysis would be to look at the supply and demand profiles of plant based end products. The consumers seeking plant based products have an expectation that they might have to overpay for the plant based version. In contrast, plant based products often have scarce competition compared to animal based counterparts. Thus, the collective bargaining favors the suppliers and the expected price of plant based products can be higher than their animal based counterparts. It is notable that these forces apply to packaged food products. For university catering, hardly any of these forces are relevant, and plant based catering is much more economical as demonstrated by the data (also presented above).