But the days of the Lord of the Flies lunchtime could be numbered. Research to be published shortly suggests that the ambience of the school canteen has a direct effect on children's eating choices. And, picking up where Jamie Oliver left off, parents in Merton, south-west London, are launching the "campaign for a civilised lunch hour".
"Queues, noise, confusion over food - pupils complain about the lot," said Jackie Schneider, chair of Merton Parents, whose drive is supported by the Local Authority Caterers Association and the School Food Trust. "We are asking them to have another look at how they do things."
The group has written to pupils asking them to lobby their schools for improvements, with prizes including water coolers for the most effective.
A report from Roehampton university, shows rigid seating arrangements, rushed sittings and a chaotic atmosphere are all worrying pupils and parents. "Most primary schools have problems with capacity," acknowledges the report. "And it is most clearly felt by pupils during the lunch hour."
After queuing for up to 20 minutes, children ate their puddings in as little as four, or left half their lunch altogether, in order to make way for second sittings or simply to escape the chaotic atmosphere.
In one school, teachers towered over the pupils with whistles. In another they began stacking chairs while children were still eating. Children are more concerned about issues such as these than food, the report found.
Brian Dow, a spokesman for the School Food Trust, said: "Short lunch hours means kids can't sit down properly or get proper nutrition. Having the right environment is as important as the food." The tension was forcing pupils to make snap decisions over food or to leave half their portions, he said.
How can things be improved? Could the answer be handing control to pupils?
At Ricards Lodge high in Wimbledon, Alison Jerrard, the headteacher, thinks so. She has invited the school council to look at ways of revamping the canteen.
Rhianna Dawkins, 15, said: "It's improved a lot. Before it was really crowded and hard to move around. Manic." Now the school has introduced a pre-ordering system for lunch to reduce queues.
A paint job - in "calming" green - and circular tables are next on the wish list. "Round tables would be more sociable," Rhianna said.
Redecoration is expensive, but for many schools the furniture continues to be the problem. As one sixth-form boy put it: "At 6ft tall, it would be nice to sit down and eat without my knees digging into my chest."
It is not just Britain where concern is growing about rushed breaks. In the United States, the after-lunch break has shrunk to as little as 20 minutes in many schools. Teachers have blamed academic pressure.
But researchers at Maine university have argued that the physical activity allowed in break times is key if schools are to tackle the country's obesity crisis.