More than 30 per cent of rubbish in black bins is made up of food waste that could be eaten or composted.

Estimates suggest up to £600 is wasted by households in Barnet each year, and as well as taking up space in landfill sites, the waste rots and produces methane gas, which is more harmful than carbon dioxide.

Supermarket shoppers are being given information by Barnet Council this week about buying and using the correct quantities of food.

Rachel Jones, a waste and sustainability officer, studied the contents of bins in the borough to analyse what people were throwing away.

She said: “People need to realise they are throwing out as much as they are. When we tell them the figures, they do seem shocked.

“It is a national problem and the findings in Barnet are borne out everywhere else.

“We are doing what we can, and we hope people will pass on the advice to neighbours and friends and start helping themselves."

The "love food hate waste" stalls are part of a campaign by the North London Waste Authority to lower food waste levels and inform people about “smart shopping”.

The council is offering recipe ideas, measurement hints and general shopping advice.

Councillor Andrew Harper, cabinet member for environment and transport, said 72 percent of waste could be recycled.

He said: “It is not that a large number of people in Barnet do not want to recycle, it's just more needs to be done in terms of helping raise the understanding about the potential of recycling.

“As that understanding improves then hopefully people will respond, and the more we can get out of black bins the better.”