Canteen Study: Why the Origin of Food Matters
A University of Hohenheim case study using a canteen menu shows that a food’s biodiversity footprint depends not only on the product, but also on where and under which environmental conditions it was produced.
In short: A University of Hohenheim case study using a canteen menu shows that a food’s biodiversity footprint depends not only on the product, but also on where and under which environmental conditions it was produced.
What the researchers have investigated
The basis was the purchase data for a full year from the Hohenheimer Mensa: about 200 tons of food for about 211,000 meals. The specialist publication summarized the procurement in 42 product groups and linked them to a global trading model. Thus, the agricultural raw materials were traced back to their likely producing countries.
For each product-origin combination, the researchers looked at several load routes: land use, consumption of surface and groundwater for irrigation, nutrient inputs in freshwaters and climate effects. These loads were weighted according to the ecological sensitivity of the respective region. Thus, the same food can perform differently depending on the origin in the model.
This is the decisive difference to a global average. An average can cover whether a raw material comes from a water-rich or water-poor region and whether the agricultural area is in an area with comparatively high biodiversity.
15 raw materials bundle around 85 percent of the footprint
In the revised version of the study, around 85 percent of the calculated biodiversity footprint of these canteens was accounted for by the 15 most important raw materials. In the case study, animal products continued to account for a large proportion of the total. At the same time, coffee, cocoa and palm oil became more prominent because of their origin from ecologically sensitive regions, although their purchased quantities were smaller.
Even vegetables cannot be treated as a uniform group. Irrigation water became an important driver for individual countries of origin and crops. This does not mean that vegetables are fundamentally problematic. Rather, it shows why product type, quantity, place of cultivation and local water shortages belong together.
An editorial clarification is needed: The university report published on 7 September still speaks of ten raw materials together with 85 percent. However, the journal had already published an author's correction on 3 September. After that it must be called "15 raw materials". Therefore, the corrected technical version is decisive for the figures in this article.
What cannot be transferred from a canteen to every purchase
The study is a case study of a single large kitchen. It represents its specific purchase quantities and does not provide a universal top list for individual foods or brands. The procurement data come from 2023, the trading model used from 2021. Probable countries of origin were modelled; individual farms or supply chains could not be evaluated.
Also within a country, cultivation methods, irrigation, soils and natural spaces differ. The study works at country level and can only record such local differences in a limited way. The biodiversity indicator used is also a modelled comparison, not counting actually extinct species. Processing, packaging and food losses are not completely included in the regionalized agricultural view for all pathways of action.
This follows for consumers: A German country of origin is not an automatic biodiversity seal, and an imported ingredient is not bad simply because of the transport route. Origin is an additional decision criterion, not a final judgment.
Four Everyday Consequences for Purchasing
- Check the country of origin for fresh fruit and vegetables: the indication is usually on the shelf or on the packaging. Compare not only varieties, but also origin and season. The seasonal calendar of the Federal Center for Nutrition helps to recognize times with a large domestic offer. (Source)
- Plan flexibly in September: Potatoes, carrots, cabbage, onions and other seasonal offers can be combined with soup, oven vegetables or stew depending on the shop. Matching ideas can be found in our autumn recipes, vegetable recipes and potato recipes.
- Quantity before keyword: In case of frequently bought foods, a suitable portion and purchase planning can avoid unnecessary loads. Do not buy coffee, cocoa or oil on stock when part of it becomes old. The case study deliberately evaluates large total quantities and high loads per kilogram separately.
- Practically incorporate plant diversity: The researchers call plant-focused dishes and pulses as possible starting points for large kitchens. For the home, it can be used regularly to incorporate beans, lentils or peas into familiar dishes. Our recipes with pulses offer concrete starting points for this.
Why "regionally" alone is too short
Regionality can support short distances, seasonal outdoor goods and local added value. However, the term is not always clear for processed foods and alone says little about the origin of all ingredients. In a regionally produced chocolate dessert, cocoa, sugar or vegetable fat can continue to come from far-off cultivation areas.
The more practical view consists of three questions: Where does the crucial raw material come from? Does it have a season or does the cultivation fit the region? And is the purchased quantity fully used? Where the origin is not recognisable, concrete information from the manufacturer or comprehensible certifications can provide additional guidance. A green landscape image on the packaging, on the other hand, is not a proof of origin.
A simple weekly plan based on the principle of origin
Do not start with a rigid ban list, but with a basic dish. For example, for a stew, you choose lentils or beans from the stock. In the shop, you complement two or three types of vegetables whose origin is indicated and which have a large domestic offer in the season calendar. Similar ingredients can be used to create a oven dish or a vegetable pan the next day. Thus, origin, season, vegetable protein sources and residual avoidance can be combined in a decision.
A regional replacement is often not realistic for stimulants such as coffee or cocoa. Here is the more meaningful question as to what quantity you actually consume and how transparent suppliers explain origin and cultivation. The study does not justify a flat-rate purchase recommendation for a particular seal; it shows above all why more precise supply chain information is important.
Conclusion: Origin is a missing piece of the puzzle
The Hohenheim case study expands the usual view of sustainable food. Whether meat, vegetables, coffee or cocoa: product name and global average are not enough for a resilient biodiversity assessment. Origin and local environmental conditions can significantly shift priorities. For everyday life, this does not mean calculating each supply chain itself. A realistic beginning is to compare seasonal options, read source information, schedule plant diversity and buy only quantities that are actually eaten.
Sources and status
- University of Hohenheim and Studierendenwerk Tübingen-Hohenheim: Reallabor Mensa: The origin of food for biodiversity counts, joint press release of 7 September 2026. (Source)
- Specht and Lask: Multi-driver biodiversity impact assessment reveals hidden hotspots in institutional consumption, Communications Sustainability, published June 9, 2026; corrected version as primary source.
- Specht and Lask: Author Correction, published on September 3, 2026; inter alia, correction from ten to 15 raw materials.
- Bundeszentrum für Ernährung: The seasonal calendar – purchasing aid for seasonal fruits and vegetables, background source; retrieved on 8 September 2026. (Source)
Author: Kochzauber Redaktion. Information and update status: 8 September 2026. The article classifys a single case study and is not a complete environmental assessment of concrete products. The cover image is an AI-generated symbol image.