The model of public procurement successfully employed at the 2012 London Olympics can also ensure that local, healthy, sustainably produced food is supplied to state schools, hospitals, prisons and army barracks, the Soil Association Annual Conference heard (8-9 October).
A Plan for Public Procurement, published in July, sets out standards that public sector bodies and their suppliers are "encouraged" to follow when buying food and catering services.
Its author Dr Peter Bonfield said: "The Government buys a lot of food but less than 50p in every pound it spends goes on British food - that's what happens if you just buy on price. Most hospital food tastes awful so you have a huge waste problem."
Bonfield was formerly head of procurement at the London Olympics, where a scorecard system was employed to rate candidate suppliers across a range of socio-economic, health, environmental, quality and efficiency criteria. "Price was a factor, but (suppliers who scored highly on other criteria) didn't necessarily cost more and quite often cost less," he said.
"With a system like this, rather than just meeting a minimum standard, they are instead rewarded for continually improving."
Having spoken to heads of several Government departments and elicited a foreword to the report from the prime minister, said Bonfield: "There is huge political will for this. I have taken (Cabinet Office minister) Francis Maude out to places already doing it. The cost equation works - you can have your cake and eat it."
He added that the Soil Association's Food for Life Catering Mark "aligns with what we are talking about". Soil Association policy director Peter Melchett said the catering mark "has engaged with Government".
Scotland - Taking up challenge of 'Becoming a Good Food Nation'
One in three Scottish primary schools are already serving Soil Association Catering Mark certified meals, said Food For Life Scotland manager Angela Mitchell. But she conceded: "Secondary schools are more challenging because (pupils) can walk out the door."
Scottish Government head of food, drink and rural communities Frank Strang added: "Public food procurement is very symbolic - we can't preach if we're not doing it ourselves."
The Scottish Government published its Becoming a Good Food Nation policy document for consultation in June, which called for a food commission to "drive change" in policy and society as well as setting economic targets for the sector.
"It should be second nature to serve fresh, healthy, local food, though there may be tensions," said Strang. "Local doesn't necessarily mean healthy."