MILAN – Water leaves a water footprint in what we eat. In California, where the issue of water is becoming relevant and almost half of all fruit and vegetables cultivated in the United States are produced, people are taking an interest in this concept, in order to understand how to measure it. The Los Angeles Times has called upon the expert Mesfin Mekonnen of the University of Twente for this purpose.
The water footprint
According to the Water Footprint Network, we use a great deal of water for drinking, cooking and washing, but even more to produce food, paper products, cotton clothing, etc. The water footprint is an indicator which enables water usage to be calculated, taking into consideration both the direct and indirect use of water by the consumer and producer. The latter, especially in relation to food, is the most relevant and implies the water used during the entire lifecycle of a product.
Foods to discuss
When talking about foodstuffs, calculations are made based on the food being analysed. It is meat which has the greatest need for water. In the United States, on average, it takes 106.3 litres of water to produce 1 gram of beef. Around 98% of beef’s water footprint is dedicated to the production of feed consumed by cattle, like grass, soya and maize. In fact, on a global scale, the water requirements in products of animal origin almost entirely relate to feed.
Methods of measurement
There are two ways of being able to evaluate the water footprint of a foodstuff: in relation to weight, or in relation to nutritional value. Both are valuable methods for understanding the impact of food on water resources. However, whether we analyse the grams or take calories into consideration, it becomes evident that foods of animal origin have a water footprint which is greater than that of plant-based foods.
by editorial staff