Guide · Data
The German Federal Food Key (BLS) explained
Behind every serious nutrition calculation sits a reliable set of data. In Germany that is usually the Bundeslebensmittelschlüssel (BLS) — the national nutrient database. What it contains, who maintains it, and why version 4.0 is a small milestone.
What is the BLS?
The Bundeslebensmittelschlüssel (BLS), literally the “federal food key”, is Germany’s national nutrient database. For thousands of foods it gives energy and macro- and micronutrient contents, and it is the standard instrument for nutrition research, dietary counselling and calculating nutrition values — including for FIC Regulation labelling.
Who is behind it?
The BLS was developed in the 1980s around the first German national nutrition survey. Today it is maintained by the Max Rubner-Institut (MRI), the federal research institute for nutrition and food, in Karlsruhe — responsible for it since 2004. So the BLS is an officially backed, scientifically maintained reference.
How is it structured?
Every food has a unique seven-character key that describes it systematically. Each position narrows the description:
| Position | Meaning | Example |
|---|---|---|
| 1 | main group — the kind of food | G = vegetables and vegetable products |
| 2 | sub-group | G1 salad vegetables, G3 brassicas |
| 3–4 | running number for the individual food | — |
| 5 | industrial processing; fat content for dairy | — |
| 6 | cooking method (in main groups B–W) | 3 = boiled |
| 7 | what the weight refers to | 0, 2, 3 without kitchen waste · 1, 4 with |
The table comes from the Max Rubner-Institut’s own explanation
at blsdb.de/bls. One group shows it at work: K120100 is
“potato unpeeled, raw”, K120134 the same potato boiled
(position 6 = 3), K120164 baked, K120184 fried without
fat.
🟢 For calculating a label, position 7 matters more than the taxonomy. We counted through all 7,140 keys of version 4.0: only 8 carry a 1 or a 4 there. In 7,132 cases the figure therefore refers to the edible weight without kitchen waste — peel, stones and bones are yours to account for.
🟡 One deviation turned up in the counting. The explanation gives digits only for
positions 3 and 4. In version 4.0, 765 entries carry letters
there (M2N6400, a cream yoghurt, for instance) — apparently 0–9
no longer stretched to the number of foods per sub-group. No consequence in practice,
but a parser of your own should allow letters.
In the current version the BLS covers around 7,140 foods — about 1,000 fresh base foods and roughly 6,000 processed or composite products. Each entry carries up to 138 nutrient values, in twelve groups: energy, macronutrients, carbohydrates, fibre, fatty acids, amino acids, fat- and water-soluble vitamins, minerals and trace elements, organic acids, sugar alcohols and others.
Diagram: Foodlex. Bundeslebensmittelschlüssel 4.0, Max Rubner-Institut.
Version 4.0 — free for the first time
BLS 4.0 appeared in December 2025, with one important change: it is free to use for the first time, published as open data under the CC BY 4.0 licence (the Max Rubner-Institut has to be credited). Earlier versions such as 3.02 were licensed for a fee. Other changes in 4.0:
- a completely revised selection of foods, matched to how people eat today (plant drinks, quinoa and buckwheat are new);
- a wider set of nutrients (vitamin K1 and K2, differentiated tocopherols, seven fibre fractions, the trace element molybdenum);
- for the first time, provenance documentation for every single data point — so you can tell whether a value comes from analysis, calculation, literature or a manufacturer.
The download is available at blsdb.de.
What is the BLS used for?
- Nutrition research and consumption surveys — the evaluation of the second German national nutrition survey, for instance;
- Dietary counselling — as the data behind common counselling software;
- Nutrition calculation and labelling — for labels and nutrition tables.
Internationally the BLS sits alongside databases such as the analytical reference work Souci-Fachmann-Kraut, the US USDA FoodData Central and the French Ciqual — all connected through the European EuroFIR network.
For ingredients the BLS does not cover, the values come from the supplier — usually from the product specification, the data sheet for that product.
From dataset to software
The BLS is a database, not a finished calculator: the download gives you foods as rows with up to 138 nutrient columns. For daily work — entering a recipe, matching ingredients to the right BLS codes, converting quantities to a portion or to 100 g, accounting for preparation and baking losses, and producing a compliant nutrition table and label at the end — you need BLS-based software.
A good one takes exactly those steps off your hands:
- Match ingredients to BLS entries — by searching, not by looking up codes by hand.
- Quantities → nutrition values, automatically, including the recipe total and the value per 100 g or per portion.
- Round the way the Regulation requires and produce the mandatory particulars as a table.
- Recognise allergens from the ingredient list and emphasise them.
Because BLS 4.0 is now free (CC BY 4.0), such tools can build on the official data without licence costs — good news for small producers who used to balk at the BLS licence.
Frequently asked questions
What is the Bundeslebensmittelschlüssel?
The Bundeslebensmittelschlüssel (BLS) is Germany’s national nutrient database. It is maintained by the Max Rubner-Institut and is the standard data basis for nutrition research, dietary counselling and nutrition calculation.
Is the German Federal Food Key free?
Since version 4.0 (December 2025), yes. The BLS is available free of charge as open data under the CC BY 4.0 licence; the earlier licence fee no longer applies. Previous versions such as 3.02 were chargeable.
Is there software for the BLS?
The BLS itself is a database, not a calculator. For recipe calculation, nutrition tables and labels you use BLS-based software that matches ingredients to BLS entries and works out the values automatically. Foodlex runs on BLS 4.0.
This article is general information and does not replace legal advice. What counts is the wording of the regulation as it applies at the time (the version of the regulation in force at the time). The English text of the Regulation is quoted from the consolidated version of 1 April 2025 on EUR-Lex (CELEX 02011R1169-20250401).