It is often said that the human body needs water before it needs food. And the reality is that we need a lot of water in order to produce food.
As the world's focus now turns to healthier diets, we must radically transform the way water is accessed, used and conserved to address the needs of the more than 800 million people suffering with insufficient food.
Take the hundreds of millions of people living in rural areas, reliant on increasingly erratic rainfall on which rain-fed agriculture is dependent. When extreme weather changes due to climate change impact water availability, the effects on their food security can be devastating.
And this is only at risk of getting much worse, as population and water demands grow whilst climate change increases the severity and number of floods and droughts in many parts of the world, but especially in vulnerable developing countries.
So, this World Food Day, as millions of people across the world show their commitment to zero hunger and healthy diets, one crucial piece of the puzzle must not be forgotten: water.
This means addressing three central priorities.
Firstly, a focus must be given to irrigation with a consideration of the needs of water. Less than 20 per cent of the world's farmland uses water from rivers, lakes and groundwater for watering their crops, meaning millions still must count on increasingly unreliable rainfall for their harvests.
Without irrigation, farmers cannot grow a variety of crops needed for a healthy diet, including off-season vegetables to supplement diets largely reliant on staple crops.
Many smallholder farmers lack access to water pumps and necessary electricity or fuel that can provide irrigation water. However, a solar-powered irrigation system offers a clean solution, allowing farmers to access a critical water supply that can make the difference between a failed harvest and a bountiful one.
Secondly, building climate resilience to floods and droughts is vital. Improving the monitoring of weather conditions as well as better forecasting systems that reach out to all, especially smallholder farmers, is critical. Better information allows better preparedness, helping farmers and those managing water supplies to take adaptive measures to cope with extreme weather.
That is why the International Water Management Institute (IWMI) have been working with local communities across Africa and Asia, to ensure their water sources are adequately managed in case of disasters. One way is by building water storage facilities like ponds and tanks that can be tapped into in dry seasons.
Another is through helping communities and governments appropriately use rivers like the Nile, Zambezi and Volta. These rivers are severely vulnerable to droughts, but provide a crucial water source for the irrigation needs of millions. Their use will only be exacerbated by the increasing water demands of growing populations, developing economies and climate change.
Lastly, it is critical that all rural people are given access to water. Otherwise, it prevents the most vulnerable members of society, including women, youth, and the elderly, as well as minorities, from growing enough food. And whilst the reasons behind migration are complex, when people go hungry it can drive them to cities, contributing to additional problems like the growth of slums, unemployment and social unrest.
For women, in particular, increasing their access to vital inputs like water, often ultimately leads to better nutritional outcomes for their entire household.
Collecting more and better data to understand why certain groups continue to have unequal access requires data that is divided by sex, age, income, migration status, and ethnicity, amongst others. This can then help policy-makers to adequately address it.
With 80 per cent of the poor living in rural areas, their capacity to cope with and to adapt to increasingly tougher climatic, environmental and societal changes is low.
The critical role of water for healthy people and a healthy environment cannot be overemphasised.
However, transforming the way water is managed can be part of the solution towards healthy diets and zero hunger. If we do not address this, ending hunger can only ever be a pipe dream.
Any views expressed in this opinion piece are those of the author and not of Thomson Reuters Foundation.
Stefan Uhlenbrook is strategic program director for Water, Food and Ecosystems at the International Water Management Institute.