Eating fruits and vegetables is better for the planet than eating meat and cheese. But crisps and sugary drinks also have a very low environmental impact: scientists analyzed some 57,000 products sold in supermarkets in the United Kingdom and Ireland, in a large study published Monday by the scientific journal PNAS.
The researchers, who hope their study can help consumers shop more sustainably without sacrificing anything to their health, also cross-referenced their results with the nutritional qualities of these foods.
Fruit juice
Syrups, sodas or other fruit juices are thus among the products sold with the lowest environmental impact – because they are mostly composed of water – but their nutritional quality is poor, points out the study.
However, researchers believe that in general, the most sustainable products are also the best from a nutritional point of view.
This work thus confirms what other studies had already advanced by analyzing single ingredients (fruits, red meat, etc.). The novelty is that the analysis here concerns products made up of multiple ingredients (sauces, prepared meals, etc.).
Trade secret
The task is difficult because the quantity of each ingredient is considered a trade secret, and therefore not very detailed: only about 3% of the more than 57,000 products, sold by eight food retailers, had a completely quantified composition.
Scientists have therefore developed an algorithm based on the few known pieces of information to assess the proportion of missing ingredients – in the United Kingdom and Ireland, the components are in particular listed in order of quantity used.
Four factors considered
To assess the environmental impact, four factors were considered: greenhouse gas emissions, use of limited water resources, land use, and aquatic eutrophication (pollution of water).
Bread, but also certain cereals, certain prepared meals or desserts (cakes, biscuits, etc.) have a relatively low or intermediate environmental impact. On the other hand, fish, cheese and meat, especially red meat (lamb, beef) have a strong impact.
“Replacing meat, dairy and eggs with plant-based alternatives could have big environmental benefits“, note the authors of the study.
But more transitions”small” can also help. For example, beef lasagna, with a strong environmental impact, could be replaced by chicken or pork lasagna, or even vegetarian.
In the future, better knowing the dosages and the origin of the different ingredients would help to determine more precisely their impact on the environment, note the researchers.
