Look up the word sustainability in the OED and it's defined as 'the avoidance of the depletion of natural resources in order to maintain an ecological balance'. On the face of it, that sounds a long way removed from the goings-on of London's kitchens and dining rooms, but it's a word you'll hear used increasingly by restaurateurs, as society's collective awareness of sustainability grows and it becomes less acceptable for us to plunder nature in pursuit of our gastronomic pleasure.

That in part explains why the Sustainable Restaurant Association – a non-profit that promotes exactly what you'd imagine it promotes – has grown from only a handful of members to more than 4,000 in just a few years, and its president, Raymond Blanc, claims to value sustainability awards above his Michelin stars. In fact, the SRA grades its member restaurants across the three pillars of sourcing, society and environment, awarding one to three stars – much like Michelin does

At its simplest level, sustainability in restaurants means not throwing good food away, but there's a host of other important things restaurateurs can do to help the planet, such as recycling almost all of our waste, and introducing LED lighting or compact fluorescent bulbs. These use 75% less energy than incandescent bulbs and last ten times longer, giving them both an environmental and economic advantage. Turning off computers and POS systems at night can also save significant amounts of energy over the course of a year.

one obstacle to sustainable restaurants may not be in the hands of the restaurateurs, but in those of the customer

By installing electronic filing software like Sharepoint and Workplace in restaurant offices, documents can be accessed online rather than printed off. A conscious choice can be made to use hybrid cars for taxis and couriers. It's a simple thing to implement, but can make a big difference in terms of CO2 emissions, as can using video conferencing to talk to external companies instead of travelling to meet one another.

Bars, too, can work towards more sustainable practices. This includes removing drinks that have an unseasonal garnish; reducing the number of drinks that use egg white to reduce wastage of the yolks; creating a house syrup that uses garnishes left over at the end of the night that would normally go to waste; using in-house filtration systems to eliminate the need for bottled water.

Suppliers also have responsibilities, and there are now those that only trade in ethical, extensively farmed and sustainable produce, and that cut down on delivery and packaging materials and use eco-friendly transport.

The criteria for evaluating the sustainability of seafood differs from that for agriculture. Restaurants should be informed and demand that suppliers are informed, too. If they can't explain where their fish is from, and how and when it was caught, restaurants probably shouldn't be serving it. Recently there has been some activity in aquaponics – companies such as GrowUp Urban Farms in Beckton grow herbs and salads on water in a tank that also contains fish such as tilapia or trout. Nutrients from the fish waste feed the plants; in turn, the plants clean the water for the fish. All in all, it's a rather neat little cycle.

Sustainability is not just a philosophy about food – it's about people, attitudes, communities, and lifestyles

It's perhaps ironic to see a return to traditional methods of cooking, eating and living that adhere to 'old fashioned' principles of 'waste not want not', nose-to-tail eating, seasonality, and preserving food, only this time with the added advantage of technology.

However, one obstacle to sustainable restaurants may not be in the hands of the restaurateurs, but in those of the customer. Diners often expect bountiful choice, but running a truly sustainable restaurant means cooking locally and seasonally sourced ingredients. While as many ingredients as possible can be sourced from the UK – from meat and fish to bread and sugar, reducing air miles and minimising the impact on the environment – in the depths of winter, this can prove quite restrictive to menus. Customers can vote with their feet and frequent less sustainable restaurants that offer ingredients flown in from warmer climes, or they can decide to take a stand and support restaurants with a sustainable and ethical ethos.

And this, really, is the crux of the matter. Sustainability is not just a philosophy about food – it's about people, attitudes, communities, and lifestyles, and small changes and efforts can make a big difference.

Has this article got you thinking? Read more about sustainability in the restaurant industry here.