Councils in England planning to switch to fortnightly rubbish collections have been advised to continue to collect food waste every week.
Fortnightly collections have proved controversial
About 180 councils in the UK collect general waste one week, and recycling the next, in an effort to cut landfill.
But critics say it is a money-saving measure which encourages rats, maggots and creates unpleasant smells.
A spokeswoman for the Waste & Resources Action programme (Wrap), which issued the guidance, denied it was a "U-turn".
Wrap says about one fifth of the UK's domestic waste is food waste - amounting to about 6.7m tonnes a year - which should be collected separately and used for composting or to produce energy.
Wrap, which advises local authorities on behalf of the government said its "revised guidance" was based on new evidence.
A spokeswoman said: "There simply isn't a U-turn, the initial guidance that was issued on alternate weekly collections by Wrap was published in 2005.
"That was a good couple of years ago - since then various things have changed, we have seen the experience of various different councils."
Among developments is the use of "anaerobic digestion technology" which breaks down food waste to release methane gas which is converted to electricity.
Pilot schemes using such plants, or in-vessel composting sites, to dispose of food waste are taking place at 17 councils across England.
"We are not saying every council that introduced alternate weekly collections has to do this - but it's an option we recommend they consider, if it is appropriate," the spokeswoman said.
The government has told councils to reduce the amount of biodegradable waste - like paper and food - going to landfill sites, in order to meet European targets and avoid a fine.
But alternate weekly collections have proved unpopular in some areas - it has prompted at least one campaign group and a campaign in the Daily Mail newspaper, amongst others, to end alternate weekly collections.
In July a public vote on the issue in Dartford, Kent showed 94% of the 10,379 people who responded opposed fortnightly collections.
And Wrap's guidance on alternate weekly collections from four months ago advised councils not to introduce the idea of fortnightly collections too near polling day.
A report by the Commons local government committee two weeks ago concluded that fortnightly collections were not right for all areas and were not proved to increase recycling.
It also said more research was needed into the unproven public health risks of leaving food to rot, in order to reassure the public.
Committee chairwoman Phyllis Starkey welcomed the new advice from Wrap but said there had never been a "government directive" that all councils had to switch to fortnightly collections.
The Labour MP told the BBC that collecting food waste separately and weekly would address residents' concerns and cut down on the build-up of methane gas in landfill sites.
But she said only areas with plants to dispose or compost food waste would be able to follow it immediately: "I think it's excellent guidance. I think it will take a while for some councils to be able to comply with it."