ST MARY'S Food Bank Alliance in Arizona claims to be the world's first food bank, founded in 1967, and is now one of the largest in the United States with sites in several cities.

Its founder, John van Hengel, had been volunteering with the Christian St Vincent de Paul Society, serving dinner to the hungry, when he heard a mother speak about how visiting soup kitchens and raiding supermarket bins were the only ways she could feed her family.

From this, van Hengel developed the idea of the food bank - where the wealthy could deposit food and the needy could withdraw it.

The organisation of food banks varies between the "warehouse" model and the "front line" model. Warehouse food banks, prevalent in America and Australia, gather food to be distributed between frontline agencies. They do not deal directly with the people who use the food banks. In Europe, the front line model is more usual - where food banks take in and then give out supplies directly to those who are using them.

The first European food bank is thought to have been founded in France in 1984, five years before the first one in Italy. They have since spread across the continent, becoming more prevalent since the financial crisis began in 2008, flourishing further since austerity began taking effect in 2010.

The Trussell Trust, founded by Carol and Paddy Henderson in 1997, runs the majority of the UK's food banks. The couple had focused their work on street children in Bulgaria, but were contacted by a British mother who was struggling to feed her children.

Henderson researched the issue of "hidden hunger" in the UK and founded the first Trussell Trust food bank from a shed in his garden. In 2004, it ran two food banks. The organisation now says new food banks are opening at the rate of three a week.

In January 2011, the Trust had launched 80 food banks - by January 2013 the charity had launched its 300th and is getting closer to its aim of opening a food bank in every British town. In 2012-13, Trussell Trust food banks gave emergency food to 346,992 people, up from 128,697 in 2011-12.

The Trust's model sees individual food banks being run by community members for that community. Non-perishable items are donated and volunteers pack, sort and distribute the food. Food parcels are designed by dieticians to provide recipients with nutritionally balanced food for three days.

Clients are referred to the service by professionals: a doctor or a social worker, Citizens Advice, Jobcentres or housing officials. The service is for emergencies only. Users are also directed to other services that can help them break out of the cycle of poverty.

The Oxford Food Bank and FareShare, a London-based charity, operate on the warehouse model. FareShare operates almost 20 depots, distributing food to more than 700 smaller agencies, mainly smaller independent operations like soup kitchens and breakfast clubs.