IT took me less than a minute to fill a bag with food, and it could feed a family for the best part of a week.

There was a well-oiled human machine at work when I joined volunteers at Bradford Metropolitan Food Bank for a recent food packing session. I was struck by the organisation, and the camaraderie. Food donations were sorted into categories and a precise method of bag-packing ensured that each food parcel contained the same range of items.

The food goes to families in need and other vulnerable people across the district. Every week volunteers pack more than 250 food bags, each containing about £15 worth of items.

As the Telegraph & Argus recently reported, the food bank is handing out more food than ever before. When the charity was set up in 2004 it distributed 28 food bags a month - now the monthly figure is more than 1,100. Benefit changes and private rent increases are two major factors, says food bank treasurer Keith Thomson. Even people in employment, particularly on zero hour contracts, are relying on hand-outs, with private rent rising faster than incomes, and low wages falling well behind the cost of food.

“Demand is the highest we’ve ever had,” said Keith. “We’re having to dig into our reserves to buy more food, to provide a range of items. We’ve always had great support in Bradford, from all cultures, but there’s a growing need - as changes and delays in Universal Credit bite and the gap between minimum and living wages continues - and we need to meet it right now.”

Donations come in from businesses, Age UK shops, mosques, churches, gurdwaras, supermarkets and schools, but the summer holiday period is a lean time. “It picks up in October, when we benefit from schools’ Harvest Festival collections, but for now we’re struggling,” said Keith. “The summer break puts more pressure on families entitled to free school meals.”

I joined Keith and other volunteers at the food bank’s Bradford base, where donations are packed up then collected by organisations such as housing associations, family support workers, community centres, child care providers and mental health groups, who distribute the food directly to those in need.

“We differ to other food banks in that we don't see the people who get the food,” said Keith, showing me boxes filled with food packets collected at supermarkets. “We use food beyond the best-by date, it’s perfectly edible but it would otherwise be thrown out. Morrison’s are our main support, and we also collect from Aldi, Lidl and Tesco. As well as giving us leftover food, they have donation boxes which customers fill.”

Picking up a large bag of crisps and a couple of flapjacks, just a day past their sell-by date, Keith added: “Sealed in a packet this is fine to eat. We also collect food left over at Leeds Festival - the stuff people can’t be bothered to take home.”

Donations are collected by volunteers and sorted into various boxes, each labelled. Some supplies, such as tinned food, cereal and pasta, are stacked on shelves. The packing system runs like a military operation: 12 boxes are lined up on a table and a different item is brought, one at a time, to each box. First I collected cereal, then pasta, noodles, tinned hot dogs, beans, rice pudding and custard, pasta sauce, teabags, biscuits and crisps. Showing me what to do was 10-year-old Abdullah, son of volunteer Usman Khan. “I heard about the food bank through Keith, who was my headteacher at Grange school,” said Usman. “I bring my three sons along every week, it teaches them about giving something back. We take so much for granted, young people need to see that others aren’t so well off.”

Volunteers range from students to retired people. “Volunteers must be aged 16-plus, but some volunteers bring their children in school holidays which is okay, as long as they stay with them,” said Keith.

Retired teacher Frances Atkins, a volunteer for seven years, arrived with a carload of food from Morrison’s in Girlington. “I collect from them five times a week,” she said. Frances and Ken Leach are food co-ordinators; dropping off and collecting food boxes in their cars. “As a teacher, I’ve seen families in desperate need,” said Frances. “One day I noticed a food bank collection bin in the Kirkgate Centre. Someone gave me Ken’s number and I went along to (former food bank depot) St Mary’s Church. I never left!” she smiled. “I love helping out. I’m fortunate, I have food in my cupboard. Many people don’t.”

As volunteers packed up food bags, a steady stream of people were coming in from organisations which distribute the food parcels. Two family support workers from children’s centres in South Bradford said the donations are a “lifeline” for many young families. “Universal Credit benefit changes have had a massive impact,” they said. “If it wasn’t for the food bank, the situation would be dire. Families rely on this. We usually take one parcel for a small family and two for bigger families. Most have children under five, but we’re expanding our service to cover ages 0 to 19. We help families to budget; looking at what money comes in and what goes out. But summer, Christmas and half-term are particularly difficult for them.”

Julie Benson, manager of Beacon House, a hostel in Manningham, collects four to six bags a week. She said: “We help men who are recovering addicts, homeless and coming out of prison to re-build their lives. It takes so long to get benefits up and running, they need immediate help. I don’t know what we’d do if we didn’t have the food bank.”

Those coming in to pick up food bags also take fresh items such as bread, cakes, vegetables and butter. More unusual donations I noticed included ice-cream cornets, soya milk and two large jars of sauerkraut. There are also donations of toiletries, baby items and sanitary products.

“Things like crisps, snack bars, dried fruit and cakes often go into food parcels as an extra treat,” said Mr Thomson. “As long as it’s all fit to eat, it doesn’t go to waste. But generally, we need non-perishable goods which we can store. We try to provide a range of food for a balanced diet. We do vegetarian bags, although there’s not much meat anyway.”

Each time we packed a bag, (which are pretty heavy when full), we added it a quickly growing pile. People continued to come in and collect bags from the pile, including a man from Centrepoint, which helps homeless young people to get jobs and homes. Meanwhile, someone from Bradford Unitarians brought in bags of donations, and Usman and his sons were helping to unload Frances’s car, wheeling in pallets of food from Morrison’s.

At the end of the one-hour session, 150 bags had been packed. Another 100 were packed the night before. Time and again, I was told the food bank is a "lifeline" for many people in Bradford. Thanks to this team of tireless volunteers, the food was going directly to them.