The average UK household throws away the equivalent of six meals every week, costing almost £60 a month, a study has found.
The waste costs the UK £12.5 billion a year despite a significant drive to reduce the problem, a report by the Waste and Resources Action Programme (Wrap) said.
The equivalent of 24 million slices of bread, 5.8 million potatoes and 5.9 million glasses of milk are thrown away every day, while the equivalent of 86 million whole chickens are discarded every year.
Recent research by the watchdog Which? found that 70% of consumers are worried about rising food prices.
But Wrap's 'Household Food and Drink Waste in the UK 2012' report suggested a lack of clarity around storage and labelling, over-estimating portions and buying more than is needed were some of the reasons consumers discarded edible food.
Households have cut avoidable food waste by 21% since 2007, saving consumers almost £13 billion, but the rate of reduction has slowed in recent years and 4.2 million tonnes is still thrown out which could have been eaten.
Almost half of this food goes straight from fridges or cupboards to the bin without making it to the dinner plate.
Wrap chief executive Dr Liz Goodwin is calling for a "major combined effort" with retailers, brands, government and consumers to cut avoidable household food waste by a further 1.7 million tonnes a year by 2025.
Tesco recently announced it is dropping some promotions for bagged salads after revealing it generated almost 30,000 tonnes of food waste in the first six months of 2013.
Dr Goodwin said: "Consumers are seriously worried about the cost of food and how it has increased over recent years. Yet as Wrap's research shows, we are still wasting millions of tonnes and billions of pounds.
"The UK is leading the way in tackling food waste and the 21% cut is a terrific achievement by millions of people who have taken action, saved money and helped safeguard our natural resources. However, there is so much more to go for and I believe we should be going for it.
"Research by Wrap shows that if we all make a major combined effort to act now, we can save up to £45 billion by 2025. It won't be easy but what a prize if we achieve it. I commit that food waste will remain a top priority for Wrap and we will be pleased to work with those who share my aspiration."
Resource management minister Dan Rogerson said: "Cutting avoidable household food waste by 21% is great news but there is still more to do.
"Everyone has a role to play in reducing food waste and we want to see businesses helping consumers to waste less food.
"Cutting waste and driving business innovation will help to build a stronger economy. We will continue to work closely with food retailers and manufacturers to achieve this goal."