Meat substitutes that are free from dairy or other animal ingredients have the lowest environmental impact, shows a study by Klara van Mierlo and colleagues at Operational Research and Logistics.
The researchers used a computer model to test four different kinds of product: vegetarian meat substitutes, vegan meat substitutes, inspect-based meat substitutes, and meat substitutes with no added supplements such as vitamin B12 and zinc. ‘We fed in the data on a range of ingredients such as soya, lupine, mealworms, eggs, vitamins and water. The computer then calculated the best composition for a meat substitute with the same nutritional value as meat. Vegan meat substitutes had the lowest environmental impact. Only in terms of water consumption did other products – the insect-based meat substitutes – use less resources.
The calculations of the environmental impact took into account the entire production process: from sowing right up to the moment that the meat substitutes were ready for packaging and transportation to the shop. The researchers included the volume of greenhouse gases emitted to produce one kilo of each product, and they also looked at how much land, water and fossil fuels are used for the production process. Acidification and manure pollution were not included in the model. Van Mierlo: ‘They are certainly not unimportant but because their effect is largely local and we wanted to make a global model, we did not include them.’
In the model the researchers opted for meat substitutes with comparable nutritional value to that of meat. Van Mierlo: ‘Then you don’t have to adapt your diet to make up for nutrients you would otherwise have got from meat.’ Van Mierlo based the calculations on the ingredients that are used in production the Netherlands, but the model can also be used in other countries