BBC Rome correspondent
In Rome, the United Nations food agency is celebrating World Food Day - the anniversary of the founding, back in 1945, of the world's first organisation devoted to the abolition of hunger.
Each year, the Food and Agriculture Organisation (FAO) chooses a theme to illustrate the paradox between the riches of our planet and the fact that hundreds of millions of its inhabitants do not have access to enough high quality food to enable them to live healthy and active lives.
The buzz word this year is the threat to biodiversity, that is to say the pressure being put on the survival of plant and animal species and the genetic diversity within those species.
For many poor farmers in developing countries, the diversity of life may be their best protection against starvation, the FAO argues.
Peter Kenmore, an FAO expert, explains: "In one hectare of a rice field, there can be over 500 species of predators, all of whom are working in their own ecosystem in a way that will protect our rice from the 10 to 15 species that are significant pests.
"So that by encouraging that biodiversity, not by applying insecticides, we can have a more sustainable rice production and still maintain the very high production levels of four, five and six tons per hectare - which is the current world target."
THE BATTLE TO HALVE HUNGER
One of the UN's Millennium Goals is to halve the number of hungry people by 2015
On current trends, the number will be cut by only a quarter
Out of more than 6,000 different animal breeds, during the past century nearly a quarter have become extinct or are endangered.
It is the same story with plants - forests, which help preserve biological diversity, are under threat from loggers, and the world's oceans are being over-fished.
It may not be obvious to everyone how important it is to preserve nature's balance, but on World Food Day we are being asked to consider what we are doing to keep it in sync.