The water we eat

“Food is an absolutely central issue when discussing water. Globally, the production of one kilo of wheat consumes 1,600 litres of water on average, while one kilo of beef takes 15,000 litres to produce. The reasons for this include plant photosynthesis and other organ functions, which require a lot of water,” says Mika Jalava, who just completed a doctorate on the water consumption of food production.

The water crisis is already a full reality in different parts of the world, and its biggest contributing factor is, by far, population growth.

“Curbing population growth will not help in the short term, there’s already so many of us. Dietary changes are needed.”

An oft-repeated solution to cutting the water consumption of food production is to replace meat with plant-based products.

“The eating habits of different countries are so varied that providing a single diet template for everyone is not a viable solution. For the vast majority of people, food is more than just a means of survival.”

As part of his study, Jalava developed an optimisation model in which country-specific diets are changed gradually, replacing animal products with plant products. Instead of making everyone’s dinner look alike, the aim is to retain the national characteristics of each country’s diet to as great a degree as possible.

“Starting with small changes is surely better than issuing a top-down decree to change everything.”

Aalto OptoFood takes production region characteristics into account

Jalava believes that the best way to change eating habits is to produce and make available the best possible alternatives.

“I’m a habitual meat-eater and hunter myself. The best way to convert someone like me is to offer them tasty vegetarian food. The food industry, chefs, bloggers and other food trendsetters play a key role in this.”

Jalava himself visits cooking courses to talk about dietary changes. When vegetarian food is done right, it’s not just a meat substitute, it provides all consumers with better eating options.  

In Finland, the irrigation water needed to produce a kilo of beef is about half the world average. The global Aalto OptoFood model he has developed takes into account how the production region affects the water consumption of food products. The model accordingly divides also Finland into map sectors with varying farming conditions, which are then utilised to calculate the water efficiency of different diets.

Feeding 10 billion people

The need for food is constantly increasing, as the global population is forecast to reach 9-10 billion by 2050. Will dietary changes, reduced food waste and increased production efficiency be enough to secure food security for the future?

“Yes. Simply adding these factors together results in up to a two- to three-fold increase in global food availability. A bigger question concerns the environmental impact of food production if unsustainable means are used to boost production.”

If, however, nothing is done, there’s plenty of reason to worry. Africa is the focal point in all relevant scenarios because, in 2100, it will be home to as many as 4.5 billion people and the continent’s dependence on food imports will be even greater than before.

From astronaut to water economics researcher

Jalava has always wanted to understand how the things around him work. As a little boy, he had clear plans for the future:

“I want to be an astronaut! And a few years later: a pilot at least! Well, then I’ll be a scientist.”

As a scientist, Jalava sticks to water. In his post-doctoral research, he intends to continue the development and expansion of the Aalto OptoFood model by examining the carbon footprint of food production, among other things.

Space is still a part of Jalava’s life after all these years. He chairs the Finnish Astronautical Society, and typically ends his presentations by showing images of the Moon and the Earth.

“Satellite images of the Earth mostly show blue oceans and white clouds, a large water surface area is our calling card. If we don’t manage our water well, we’ll have to travel a damn long way to find more!”

Text: Marjukka Puolakka
Photo: Iiro Immonen

This article will be published in the Aalto University Magazine issue 25, October 2019.

The public examination of the doctoral dissertation of Mika Jalava, Master of Science (Technology), was held on 30 August 2019 at the Aalto University School of Engineering. The title of the dissertation is The water we eat: Methods for estimating water use of diets in changing food. The field of the dissertation is water management, food safety.

https://www.aalto.fi/en/events/defence-of-dissertation-in-the-field-of-water-management-mika-jalava-msc-tech