A government push to get schoolchildren eating more lentils, pulses and beans at lunch could have a “devastating effect”, making catering services unviable, school meal providers have warned.

Proposals for healthier meals in English schools, which would limit the amount of desserts and reduce “grab-and-go” items such as pizzas and sausage rolls, would pile pressure on an already struggling sector, caterers said.

Brad Pearce, the chair of The School Food People, a trade body that represents school meal providers, warned the changes were likely to drive up costs and push pupils to find somewhere to buy junk food.

“We think there will be unintended consequences of secondary school students who buy food and drink on the way to school, or leave schools at lunchtime and buy it on the high street.

“That has a devastating effect on the viability of our services in terms of revenue, and payment for staff and food and ingredients – whether that’s a school that runs its own service or a large catering provider,” he said.

Tracey Smith, the chief executive of the caterer Sodexo’s school and university business, added that caterers already had to balance “nutrition versus what children find appealing and what they actually want to eat”.

She said: “What we don’t want is children to start bringing in packed lunches that aren’t balanced because they think that they do not like the school food or that they cannot afford it.

“If you are looking at a really high-quality vegetarian dish, that could be the same price as a meat dish.”

The proposals announced earlier this month and the first major update to school food standards in 13 years, will prioritise children’s fibre intake. Some changes are expected to come into effect in September 2027, including making it mandatory for all school puddings to be made of at least 50% fruit. Deep-fried items such as battered fish and chicken nuggets will be banned.

Lentils are likely to be incorporated into more meals as a healthier and nutritious replacement for meat in some cases, although suppliers have said that – given the legumes are mostly imported into the UK – it could drive up their costs further.

The wholesaler Bidfood, which supplies school caterers across the country, said stricter demands would add further strain on the industry.

Gavin Squires, a business development controller at Bidfood, said: “Changes to menus and product specifications, alongside reduced menu flexibility in certain areas, could have implications for sourcing, availability and stock management, at a time when supply chains are already stretched.”

The average cost of a school lunch in England was £3.16 last year, although caterers said prices were primarily influenced by the level of funding from the government.

The government spends £1.5bn every year to provide free school meals for about 3.4 million children. This figure is expected to rise from September this year, when all households in receipt of universal credit will be entitled to free meals, extending access to more than 500,000 children.

Elevated inflation has already increased pressure on caterers, who normally operate on low profit margins. The war in Iran is expected to further push up food prices.

Compass Group, one of the biggest providers in the sector, has a net profit margin of only 4%. Sodexo, a group that also provides facilities management services, has a margin of 2.8%. Bidfood’s margin was about 3% in its 2025 financial year, according to accounts filed at Companies House.

Members of The School Food People have reported 50-70% inflation in food prices in their supply chain in the past three years, Pearce said.

“The pressures from the increase in the UK living wage and the London living wage are huge,” he said. “Plus you have the war in the Middle East and increases in fuel costs; it is adding pressure on what is already a very difficult situation.”

However, Stephanie Slater, the chief executive of the charity School Food Matters, said healthier food standards did not necessarily translate to higher costs.

“There is a real squeeze at the moment with food inflation and labour costs,” she said. “But it is a broader issue that it is less about food standards and more about the fact that the system needs more funding.”

The Department for Education is consulting on its proposals until 12 June, with plans for the new rules to come into force next year.

The proposed changes come amid rising concerns around children’s health, with data for 2024 released by the NHS in January showing that 24% of nursery and primary schoolchildren were overweight or living with obesity.

It is the first overhaul to school meals since 2012, when the government-commissioned School Food Plan was written by Henry Dimbleby and John Vincent, the co-founders of the food chain Leon. The revamp comes two decades after parents at a school in Rotherham, South Yorkshire, caused a storm of national coverage after being pictured passing food through its iron railings in an what was portrayed as a protest against the chef Jamie Oliver’s healthy-eating campaign.

A spokesperson for the Department for Education said: “Our new school food standards were thoroughly tested with caterers, schools and nutritional experts to make sure they are deliverable, realistic and don’t have detrimental knock-on effects to parents and pupils.

“Throughout this process we found that many schools across the country are already creating affordable, delicious meals that meet these standards. Several saw the cost of meals fall.”

The spokesperson said a “phased approach” would be taken to give caterers time to adapt.