Removal of packaging must be done carefully to avoid food waste.
Retailers should sell fresh fruit and vegetables loose and leave "best before" dates off packaging as part of efforts to cut food waste, experts have said.
New advice for packaging and labelling fresh produce has been produced by waste reduction body Wrap, the Food Standards Agency and the Environment Department to tackle one of the biggest areas of food waste.
Around a fifth of food brought into UK homes ends up as waste, including £4 billion worth of binned fruit and vegetables, costing the average household hundreds of pounds a year.
The new advice encourages retailers to offer fresh produce in a range of pack sizes and loose, where it is suitable to do so - which can cut plastic packaging and give customers the opportunity to buy the amount they need.Leaving off the "best before" date on some packaged items can also help reduce waste, for example with potatoes, by encouraging people to use their judgment more.
It comes as a new retail survey by Wrap, looking at 2,000 products in nearly 60 supermarkets, said it has seen good progress on implementing some of its previous recommendations.
But while supermarkets and brands have implemented best-practice guidance on date labels, product life, pack size and storage and freezing advice, more work needs to be done in a number of areas.
Peter Maddox, director at Wrap, said public concern over plastic packaging had increased since the last survey in 2015, and the guidance had been updated to deal with single-use plastics for fresh produce.
"Removal of packaging must be done carefully to avoid food waste, and we now we have a clear set of principles that will help limit plastic use, and ensure removal is done in a safe and sustainable way.
"The other significant development we recommend is removing best before dates from uncut fresh produce where this doesn't risk increasing food waste, and the guidance helps this decision-making," he said.
Wrap said better labelling can help customers reduce the two million tonnes of food thrown away because it is not eaten in time, and the 1.2 million tonnes that ends up in the bin because too much has been cooked or served.
In 2017 new best-practice guidance was published on how to apply and use food date labels and other on-pack advice, with the Government saying last year that it expected food businesses would fully adopt the recommendations.
In its latest survey, Wrap said it found good progress in areas such as removing date labelling on pre-packed unprepared fresh produce, and use of the snowflake label to show that items could be frozen.
The product life of milk and cheese had increased, and most goods carried the correct home storage advice, with many retailers using the "little blue fridge" logo to show foods that last longer when refrigerated at home.
But more work was needed in areas such as removing "open life" statements - which tell a consumer to eat a product within a certain time after opening - for things such as blocks of cheddar which have an average life of 64 days but 90% of packs advise eating within five or seven days.
Bagged salads have a very conservative open life of just one day and this could be extended, while smaller pack sizes for bread were relatively more expensive.
Wrap also wants to see an end to "freeze on day of purchase" labelling as it can lead to people throwing away good food instead of putting it in the freezer up until the date mark, with three retailers removing such labels and eight more removing the remaining few products with this statement.
Mr Maddox said: "Overall, we've seen good progress from all, but we have also been very clear with each company where more work is required, and where they are falling short."
Emily Beament is the PA environment correspondent.