Teachers have claimed that going to work is “like walking into the land of the giants” because their pupils are now so tall and heavy.

       The weight of 14-year-old-male students has ballooned from an average of 5st 10lb in 1970 to 8.5st, according to one of the leaders of the NASUWT.

       The average height is also said to have risen in the past 50 years from 4ft 10in to 5ft 8in, Elaine Paling told delegates at the teaching union’s annual conference in Birmingham on Sunday.

       Whilst telling the audience she was “a big fan of statistics”, the history teacher claimed that these figures had been taken from the World Health Organisation website.

       However, a study from University College Cork placed the average height of a 14-year-old boy in 1970 at 5ft 3in and in 2007 at 5ft 6in.

       ‘Small desks put physical development at risk’

       Ms Paling told the audience that pupils’ “physical development” is being “put at risk” by “being wedged into desks that are too small and made to sit on plastic chairs that are much too narrow and short backed”.

       “And where do they put those feet?” she added. “Usually in the aisles, a perfect trip hazard. And why are school desks and chairs not bigger? Because they wouldn’t fit 30 students into the classroom.”

       Fergal McGuckin, another teacher, told the conference that walking into his A-level classes felt like entering “the land of the giants”.

       “As someone who’s a standard 5ft 8in, I really do feel vertically challenged in those environments,” he added.

       Vote on setting maximum class size limits

       Their comments arose during a union vote for Downing Street to set maximum limits on class sizes.

       Members claimed that pupils were using the same-sized classrooms that their predecessors had in the Seventies.

       In 2021, analysis by the Labour Party found that the number of secondary pupils in classes of at least 31 had increased from one in 10 in 2010 to almost one in seven pupils.

       It suggested that the number of primary school pupils in classes of 31 or more had increased from one in nine in 2010 to one in eight pupils.

       The analysis, based on figures from the House of Commons library, found that the number of secondary pupils in class sizes of 31 or more increased by more than 130,000 between 2016 and 2020, a rise of 43 per cent.

       The Department for Education said: “Schools and education staff have gone above and beyond over the course of the pandemic to make sure every child receives the education they deserve.”