Doggy bags are part and parcel of eating out in the US. But many British diners struggle with the idea of asking to take their leftovers home, something campaigners want to change.

In the UK, it is a rarely heard request. And if one does have the audacity to ask for a doggy bag, it will probably be uttered under one's breath or behind one's hand.

There is no such shame attached to doggy bags in the US, where they are overtly offered on a menu or freely handed out by the waiting staff as part of the service.

While the larger portions in the US may feed the need for more doggy bags, Britons are reluctant to ask for one regardless of how much is left on their plate.

A recent survey by the Sustainable Restaurant Association (SRA) showed 25% of diners were too embarrassed to ask for boxes, with 24% wrongly believing they were against health and safety policies.

We Americans don't have the airs and graces of Europeans Charlie Wolf, American broadcaster

The organisation is launching a new campaign to embolden diners to ask for doggy bags and to encourage restaurants to make patrons feel more comfortable about it.

The Too Good to Waste initiative will see 25,000 biodegradable boxes dispatched to about 50 participating restaurants in London, including the Michelin-starred Quilon and chains including Wahaca and Leon.

They are hoping it will help reduce the amount of waste in the UK - a typical restaurant annually throws away 21 tonnes of food, the weight of three double decker buses, according to the government's advisory body Wrap.

But old habits die hard and this is not the first time such a campaign has tried to convert Britons to the doggy bag culture.

In 2009, Hugh Fearnley-Whittingstall was one of several high-profile chefs who backed a supermarket's call for doggy bags to become the norm. But the campaigners have faced an uphill struggle.

Dining out in the UK has certainly become more and more common for many people. It was once the preserve of the well-to-do but more people started to eat away from home in the 1960s with the emergence of French bistros and Italian trattorias.

Food waste in the UK 21 tonnes - the weight of three double decker buses is wasted in food per restaurant per year

30% of this comes directly off diners' plates

£724m could be saved by the food industry each year through recycling and food waste prevention

10% of all produce caterers buy is thrown away Source: Wrap

An explosion of restaurants coincided with a rise in spending power, and Britons are now spoilt for choice when it comes to eating out.

Even fine dining has been opened up to the masses. But while eating out has lost some of its mystique, starched-white tablecloths, over-attentive staff and a confusing canteen of cutlery can still make some people shift uncomfortably in their seats.

In 1981, 957 million meals were served in restaurants and pubs in the UK whereas an estimated 1,661 million will be dished out this year, according to food consultancy Horizons.

So if more and more Britons are eating out, why is there still a mental block when it comes to doggy bags?

Food historian Colin Spencer, who has never asked for a doggy bag, says it is not part of the culture.

"It's a shyness about appearing to be greedy. There's a kind of nervousness which I think is quite natural."

In addition, waste has been a symbol of wealth and nobility throughout history.

"The waste went to feed others. It went to feed the kitchen staff and in the Middle Ages, what was left after the kitchen staff went to the poor and beggars waiting in the courtyard," he says.

Although it may be a reflection of the fact you obviously thoroughly enjoyed the dish, scraping the last morsel from the plate is unnecessary Liz Brewer, Etiquette expert

"I think that feeling is still there, so even though you are out in a restaurant there's partly that feeling that 'I can afford to do this, I don't have to clean my plate'".

Paul Buckley, senior lecturer of consumer psychology at Cardiff School of Management, says doggy bags have an image problem in the UK.

"What others think and social conformity puts pressure on you as a customer. Anything they think poor people may do, they won't.

"Others will ask for doggy bags and make excuses. They might want the thing to eat at home the following day but will say, 'It's only for the cat'."

This reluctance may boil down to the British desire not to create a fuss, or it could be the belief that it is good manners to leave a few morsels on your plate.

Liz Brewer, etiquette expert from TV series Ladette to Lady, recalls being told as a child to leave some food for "Mr Manners".

"Although it may be a reflection of the fact you obviously thoroughly enjoyed the dish, scraping the last morsel from the plate is unnecessary."

However, modern-day etiquette should involve a good dose of common sense.

"Common sense should tell them that food should not be wasted and that asking for a doggy bag makes sense," Brewer notes.

The word doggy bag originated in the US and American-born London-based broadcaster Charlie Wolf says they are socially accepted in his native country.

Eating out There were 2077 million meals eaten out in 2010 at restaurants, take-aways, pubs and hotels

£33.5bn was spent on food and drink in 2010

29% of all food and drink consumed is from dining out Source: Horizons

"We Americans don't have the airs and graces of Europeans. Americans are a bit more of the people, more pedestrian. There's nothing embarrassing about asking for a doggy bag.

"We don't want to see waste. There's a sense of working hard for your money and wanting value for your dollar."

He recalls how his mother used to make an omelette with the remains of meals from their favourite Chinese restaurant. She also used to bring any uneaten bread rolls home.

"We were upper middle class. My parents came through the Depression and I'm sure that had a bearing even when they became successful."

Spencer's background is middle class but his parents didn't eat out when he was growing up. His recalls how his spinster aunt was too worried about the cutlery etiquette to dine out.

Image caption Take-home boxes have yet to take off in the UK

"You didn't eat out in the 40s and 50s and it only really began to change in the 60s and only very slowly."

Despite the long-term growth of the eating-out sector in the UK, it is currently battling against a volatile economy and changes in disposable incomes, according to the latest statistics from retail analysts Mintel.

Their surveys from May suggest a third of diners have reduced their expenditure on eating out per month or reduced the frequency of visits. More than a fifth of those who have cut back order tap water, not bottled water.

So perhaps the economic climate might force Britons into trying out take-home boxes, which many restaurants already offer.

Japanese chain Wagamama offers doggy bags at all 73 of their restaurants if diners request one, and even the more upmarket restaurants are willing to assist.

Even a swanky restaurant like the three-Michelin star Waterside Inn in Bray would give you a bag, although it admits it has never actually had such a request.

"If they did ask, the customer comes first so we would do it," says Gina Curtis, secretary to chef Alain Roux.

"I don't think they will ever ask, they have too much money to ask."

It is debatable whether the various British cultural attitudes to doggy bags will be overcome to help reduce the amount of food thrown away.

But Buckley compares the situation to the public smoking ban and says people's perceptions can change, albeit very slowly.

"To go against the norm in society takes a lot of confidence. There are unwritten rules in society people will follow automatically. When these adapt, so do people's actions."

Though perhaps all it needs is a name change. In Britain, a doggy bag can be confused with a pooper-scooper, which deals with a different kind of waste altogether.