Researchers at the Universidad Politécnica de Madrid, in collaboration with the Fundación Botín Water Observatory, have carried out a study on food consumption habits and associated waste patterns in Spanish homes, in order to assess the impact on domestic water resources and identify possible ways of preventing water wastage. The conclusions indicate that diet type has a greater influence than food product wastage on food-associated water footprint. More sustainable and healthy diets could generate important collateral environmental benefits with respect to land, energy and water.
It is estimated that world population will exceed 9 billion by 2050. This population growth, along with the fact that our society is increasingly urban, will pose a challenge of enormous dimensions, i.e., the production of more food to supply the entire world population, a population with changing patterns of consumption.
Agriculture accounts for around 70% of all water consumption and competition for water has led to increased scarcity in many parts of the world. As a result, water is one of the main constraints on agricultural production, making the management of this resource vital.
At the Universidad Politécnica de Madrid Centre for Studies and Research on Agricultural and Environmental Risk Management (CEIGRAM), a number of studies have been carried out on the relationship between diets and the volume of water needed to produce the ingredients associated with these diets. An example is a comparative study undertaken by Alejandro Blas, Alberto Garrido and Bárbara Willaarts on American (USA) and Mediterranean diets. The same authors recently carried out another study to estimate the water footprint (i.e., the quantity of water needed to produce a good or, in this case, a set of food products) of diets and food waste in households over the course of one year.
The results for the period analysed (October 2014-September 2015) show that the water footprint associated with consumption in each Spanish household is 52,933 hm3, the equivalent of 3,302 litres per person per day, i.e., the amount of water that would be consumed in 33 five-minute showers. Meat and animal fats (26%), and dairy products (21%) account for the greatest percentage of total water footprint. Approximately 41% of the water footprint comes from other countries. In other words, it is “virtual imported water” and the main countries of origin are Tunisia, Portugal and France.
The water footprint associated with food waste (leftovers on plates and food that expires or goes off prior to consumption) is estimated at 2,095 hm3 for Spain as a whole, the equivalent of 131 litres (or a large bathtub) per person per day.
As Alejandro Blas, a researcher involved in this and other studies related to the issue, points out “although some of the population continues to follow a Mediterranean diet, Spanish consumption patterns are changing towards a diet with greater consumption of meat and sugary products than the recommended quantities”. In the light of these results, he concludes that “a Mediterranean diet, in which fruit, vegetables and fish account for the most of the food intake, would afford great water savings in households”.