Supermarket shoppers should realise that 15 pence of every pound they spend is going into the bin, said Jennie Price, chief executive of WRAP -- the Waste and Resources Action Programme.

"It's very easy to buy lots of food, we have masses of choice, we like to make sure there is plenty in the fridge and we just don't see what we throw away," Price told BBC Radio 4's Today Programme.

Her agency interviewed 1,900 people for its research and found that only 10 percent considered they were throwing away a significant amount of the food they bought.

Price recommended people eat the food in their fridge in sell-by date order to avoid unnecessary waste.

Supermarkets could also help by putting fewer items in packs of meat, fruit and vegetables.

"If you want three pork chops, they shouldn't sell you four," she said. "If you eat half a bag of salad, you should be able to reseal it and eat the rest the next day."

As well as saving shoppers money, planning ahead and buying only what was needed would also help the environment.

"When you think about the amount of effort and energy -- carbon-type energy -- that goes into food production, this really is a serious issue for everybody, including the supermarkets," she said.