By Duncan Walker
BBC News Online Magazine
Theatres are getting increasingly cramped, with less leg room and the bodies of audience members squashed closer together. Why?
A trip to the theatre these days is more likely than ever to find you shifting uncomfortably in your seat for space.
But while customers may be tempted to blame the architects or penny-pinching owners for their discomfort, the cause of the problem lies elsewhere.
Audience members are bigger than ever before, and it's not just their well-documented march towards obesity that is to blame; the average person is also taller.
Accommodating people's spreading bodies is a problem for everyone from clothes designers to airlines - but it is particularly keenly felt by theatres, many of which were built for people from a different, smaller era.
At the Royal Festival Hall on London's South Bank, a £71m refit will include the removal of 108 seats - just so audiences have more room to stretch out.
Managers believe Britons are one-and-a-half inches taller than they were when the complex opened in 1951, leaving people fighting for space.
They have decided to give each row of seats an extra three inches (about eight centimetres) of leg room - a task which sounds easier than it is in reality.
"The Royal Festival Hall is a little bit unique because it's Grade I listed and so we're refurbishing the existing seats rather than replacing them, because they're part of the iconic interior," says architect Greg Holme, from the firm Allies and Morrison.
Outwards and upwards
It is not just the Royal Festival Hall which is having to cope with bigger audience members - and it is lucky it has seats which are deemed large enough for larger behinds.
The Royal Festival Hall opened in the 1950s
Other theatres are having to take notice of audience members' spread outwards as well as upwards.
"There's a much larger minority who are clinically obese these days and it's a real problem. It's a combination of the wrong food and cutting down on exercise," says Tom Stewart, managing director of ergonomics firm Systems Concepts.
Calling for £250m over the next 15 years to refurbish 40 London theatres, the Theatres Trust said: "Most theatre buildings still reflect the conventions of a period...when theatre goers were physically smaller."
Its director, Peter Longman, says most theatres were built around 100 years ago, when the average person was a full four inches shorter, and considerably lighter.
'Count every penny'
Most buildings are still to be re-fitted with the needs of 21st Century audiences in mind. Doing so has the potential to be costly both in terms of building work and the possible loss of seats.
"If you're a subsidised theatre it may not matter that you have 200 people less, but if it's a commercial theatre you need to count every penny," says Mr Longman.
Nevertheless, theatres cannot afford to ignore audience comfort.
"There's one well known theatre where I refuse to sit because the seats are so uncomfortable. If you have a nasty time you remember," says Mr Longman.
Official figures don't go back as far as the 1950s, but the Department of Health is in no doubt we are a growing nation.
While the growth spurt thought to have been caused by better diet and fewer childhood diseases following the 1950s has eased, Britons are still getting taller.
Between 1993 and 2002 men grew one tenth of an inch to 5ft 9ins (174.8 cms).
The spacious Royal Festival Hall
The height of the average woman increased by slightly less, to 5ft 3ins (161.3 cms).
Changes in Britons' weight have been more dramatic.
Between 1993 and 2002 the average man put on 8lb and now weighs 13 stone (82.4kg). Over the same period the average woman put on 6lb and now weighs 11st (69.4kg).
It seems the challenges faced by theatres really are a growing problem.