A scientist says the emerging debate of virtual water will soon become as important as the issue of greenhouse gas emissions.
Virtual water is typically measured as the number of litres required to grow, manufacture and market 1kg of any food product.
Dr Brent Clothier from Plant & Food Research says research shows it takes 140 litres of water to produce a cup of coffee and even more for a plate of pasta.
He told Country Life: "The Victorian State government in Australia has produced a calculation to show that the virtual water in a bowl of pasta is some 200 litres."
Mr Clothier said there's currently little accurate data which measures the virtual water content of food grown in New Zealand.
For apples, he said it's about the same as in the Netherlands and kiwifruit is about 20% of that in Australia.