The reasons why almost one billion people don't get enough food to eat are complex and inter-related.

A major reason for food shortages in poor communities is crop failure due to drought, floods and other abnormal weather events. When crops fail, poor rural communities who have no other resources to pay for food go hungry.

Another major cause is conflict. Wars destroy farms and fields, kill farmers and displace millions of people around the world. This means less food is produced and families who flee and become refugees lose their incomes and livelihoods.

In regions like southern Africa, food production is being affected by the HIV and AIDS pandemic, which has left many farmers sick and unable to grow food.

The current Global Food Crisis has brought some other major causes of hunger into sharp focus. These include climate change, and a rapid rise in global food prices linked to high oil prices, increased biofuel production and export restrictions.