Eat everything or get out: restaurants and the new bossiness

As many restaurants seek to reduce costs and waste, 'austerity dining' is becoming increasingly popular.

Wafu, a restaurant that serves Japanese food in Sydney, has adopted a policy that diners must finish their meals or risk being asked not to return.

"Please note that vegetables and salad on the side are NOT decorations. They are part of the meal too" In a normal year, you'd expect a restaurant menu that ordered its customers around like this to fail within weeks. This, however, is no normal year - and this is written on the card at Wafu, Sydney's most talked-about restaurant opening this year. With a belief that avoiding waste is as important as making delicious food, the Japanese restaurant instructs its diners to eat everything on their plate, or risk being asked not to return. While this bossy frugality might make Wafu seem a complete one-off, its austere, no-frills approach is one of the year's biggest restaurant trends.

Across the world, restaurateurs are trying to tailor their menus to the mood of a period when money is tight and conspicuous consumption seems embarrassingly old-fashioned. From banning disposable takeaway food containers to letting customers pay for their meals with carrots, these restaurants are seeking out ways to be cheaper, less wasteful and more user-friendly. Inevitably, this strange new world of austerity dining is in part a clever marketing ploy - there's nothing like a bit of social conscience to make businesses look cool during a recession. But underneath the PR puff, many establishments are seeking a genuine alternative to the expensive excess of the boom years, and their quirky approach is getting diners excited about discovering alternatives to gastronomic greed.

The austerity dining trend takes various forms, from one-off establishments with a semi-educational bent, such as Wafu, to the many mainstream restaurants with pay-what-you-can menus. These menus have become a familiar feature in many big cities, with restaurateurs taking the gamble that diners will pay a decent price for their meal without being obliged to. In London, Little Bay and Zebrano have both tried this out, and have found that the gamble generally pays off, as diners are likely to return to the restaurant on days with fixed prices. Meanwhile, several American establishments have introduced flexible prices every day of the week. Community cafés such as So All May Eat in Denver and One World Everybody Eats in Salt Lake City have mixed their business with small-scale social activism, with part-volunteer staff trying to bring people of all incomes together. This has proved so popular that larger companies are now muscling in. The growing restaurant and bakery chain Panera Bread has opened its own not-for-profit diner in St Louis, Missouri, and is now planning to roll out a national network.

By far the largest pay-what-you-can project so far, however, comes from the Australian community activist-led mini-chain Lentils As Everything with four restaurants and a school canteen. While the name might make any veggie-sceptic's blood run cold, its unique blend of no-fixed-price meals and social activism has made it nationally famous and hugely popular. Attempting in its own small way to promote a kinder, more inclusive society, many of its staff are former refugees, training to launch themselves into regular jobs.

In California, another restaurant is trying to promote a socially conscious ethos through a radically different way of sourcing and charging for its food. Forage, which opened in Los Angeles's bohemian Silverlake neighbourhood this year, allows diners to pay for their meals by bartering their own home-grown produce. Developing on the trend for locally sourced dining, Forage has recruited a circle of local gardening enthusiasts who grow as much as possible of the restaurant's food in their own back gardens.

As Sabrina Reinbacher, one of Forage's managers, explains: "The mild weather here means that there's always something in season in local gardens that we can use, from fruit and tomatoes in summer, to citrus fruit and squash in winter." Despite the name, not everything on the menu is as wild as you might imagine - at least, not yet. Local red tape means that Forage has to get its back garden producers certified by the authorities, a process that takes some time. Currently, just under a third of the food comes from gardens, the rest is from farmers' markets. But while it's early days for the project, there's still something tickling about knowing your salad grew next door. As a financially viable,community conscious way of taking on both environmental concerns and keeping prices low, their ethos chimes brilliantly with the current mood of restraint.

All these bright new ideas are exciting, but a social conscience alone doesn't make food taste good. Isn't there a danger that all this worthiness might make these restaurants just a little grim? Conscientious consumerism is one thing, boring diners with a dressed-up soup kitchen and sermons about waste is another entirely. Forage avoids this accusation entirely - among its fresh garden produce, one of its popular dishes is (locally sourced) flank steak marinated in Coca-Cola, hardly the sort of dish to curry favour with consumer activists.

Elsewhere, however, things are a little more severe. Lentils As Everything's food is as vegetarian as its name suggests, which doesn't necessarily mean it's dull, of course, but limits it to something of a niche. Wafu's waste-not-want-not ethos, meanwhile, is complemented by a Japanese menu that is every bit as spare. While meat and fish are served in small quantities, the food is an otherwise macrobiotic affair containing no gluten or wheat, no dairy products or eggs and no refined sugar. Chef Yukako Ichikawa's menu is even punctuated with exhortations to eat up, specifying: "Finishing your meal requires that everything is eaten except lemon slices, sushi ginger and wasabi."

Apparently this approach doesn't deter people, as Wafu's dining room is apparently full nightly. What's more, its approach is not a one-off. Montreal's Spirite Lounge has recently launched with a similar system, fining diners who fail to finish their main course $2 (Dh7.3) and denying them the right to order dessert. While such heavy-handedness might sound grating, the restaurant trade is generally wasteful and environmentally irresponsible. It's possible that austerity dining is proving so popular because it taps into people's sense of guilt at their own habits. The meals at places such as Wafu can act as a form of mock penance, helping diners to feel virtuous while allowing themselves a little healthy self-indulgence. This makes some sense - in a period of economic insecurity and change, there's something perversely comforting about being told what to do. But is all this austerity more than just a passing fad? Probably not. While guzzling and luxury may swing back into fashion as the economy bounces back, the growing success of these dining projects suggests that these odd but admirable start-ups may well be just the beginning.