With about 60 per cent of our waking hours spent in work, and about 75 per cent of working-age people in the UK in employment, one adult meal in three is eaten at work.

The prandial problems facing many employees are similar to the crisis in schools.

Staff restaurants and work canteens, like school dining halls, often serve poorly sourced foods, bought in bulk from institutional catering providers, prepared and presented with little flair, and lacking adequate nutrition. In fact, several of the catering companies used for schools also provide food for work canteens. "Many work-places are providing stuff that wouldn't even qualify as school dinners," says Peter Melchett, the policy director of the Soil Association.

And for many employees there is not the time or the provision for a decent lunch.

This is illustrated in a legal case from December 2005 in which the US retail giant Wal-Mart was ordered to pay $172 million (£99 million at the time) damages to staff who claimed they were systematically denied their right to a 30-minute unpaid lunch break. One British worker in five never takes a lunch break, according to a survey by the catering providers Eurest. The average lunch break for workers remains at a record low of only 27 minutes. Women are the most workaholic, with one in four working through lunch.

Some businesses, however, have realised the importance of food to their employees.

At the award-winning London headquarters of Sainsbury's the staff canteen has the buzz of a contemporary restaurant. A long curved wall of orange and oatmeal stripes and wooden Wagamamma-style communal tables sets the scene for the fresh colourful dishes on offer. I choose wholesome lentil and garlic soup; a spinach and pepper fritatta with rocket, olive and cherry tomato salad; and a portion of stir-fried fennel, leek and red onions. My fresh fruit salad was juicy chunks of papaya, mango, melon and plums. A delicious meal for about £4.80.

As a former winner of the BBC's Big Challenge award for the healthiest large employers in London, Sainsbury's employees are encouraged to eat five items of fruit and vegetables a day, two portions of oil-rich fish high in omega-3 fatty acids a week, drink two litres of water a day (a water loyalty scheme makes every fifth bottle bought free) and walk 10,000 steps (almost five miles) a day. Healthy meal choices are rewarded with scratch-cards offering gifts such as exercise videos and step machines; there are regular trials of exotic fruits, and staff can help themselves to probiotic drinks. "We serve food that's as good as you'd get in any restaurant," says Danny Lemon, Sainsbury's general facilities manager. Fresh produce comes from local suppliers and the head chef, an ex-City restaurateur, checks the fish for freshness himself.

Some contract caterers are beginning to get the message, too, and are adapting their menus. "Although many contract caterers remain slaves to junk food, the focus is shifting to healthy-option menus," says Emma Hockridge, the project officer at Sustain, an alliance for better food and farming that offers advice on supply chains and training for catering managers on how to source more sustainable food. According to the Department of Health, whose White Paper Choosing Health looked at food provision in the workplace, evidence indicates that a "healthier workforce is more likely to perform well".

Dr Amelia Lake, of the Human Nutrition Research Centre at the University of Newcastle, agrees. She studies why we make the food choices we do and says "workplaces have enormous potential as a supportive environment for dietary interventions and for promoting change in large segments of the population".

"A lot of employers don't realise that encouraging employees to eat more healthily and to take a more active 15-minute break away from the desk each day could actually increase productivity as well as contribute towards long-term weight control and good health," says Dr Frankie Phillips, a registered dietitian with the British Dietetic Association.

A slew of enlightened companies have already taken inspired steps to transform mealtimes. The seven staff members of one Durham-based company take it in turns to bring in lunch for each other while another offers the healthy option free on its daily menu.

At just 60p a pot, "pukkola" is a popular choice at the Standard Life Healthcare restaurant in Guildford. The breakfast of oats, yoghurt, honey, walnuts and fresh raspberries, inspired by Jamie Oliver, is part of a health drive that also includes free fruit days for the company's 300 staff. It has steered its contract caterer, Sodexho, away from traditional canteen food to healthier options, such as vegetable cottage pie and a salad bar.

How do you make companies such as Sodexho provide healthier food? David Furness, of Standard Life Healthcare, says: "In our case it was important that it was led from the top. Our chief executive was genuinely keen on making changes. It's about co-operation and it helps if the catering team is already tuned in to the healthy food culture. But don't expect changes overnight."

The financial services company Prudential ran an eight-week "look good, feel better" programme that included on-site seminars by nutritionists. It also persuaded the celebrity chef Antony Worrall Thompson to create a new year healthy menu for its staff restaurants, which cater for 8,000 people at sites in Reading and Stirling. Main dishes included seared soy-glazed tuna with Asian crunch salad, high in brain-boosting omega-3s and antioxidants.

"The drive comes from employees," says Andrew Powles, a people-policy manager at Prudential. "I get requests from staff for Fairtrade pumpkin seeds in the vending machines instead of Mars bars."

CATER FOR CHANGE

* Ask your catering manager what is specified in the catering contract. If it's a cheap service offering chips and reconstituted meat, ask for a better quality contract. It's been proved in schools that fresh, local seasonal foods can be cheaper.

* Ask questions about the food served in your canteen. For example: What country/county/farm does the meat come from? is it free-range and/or organic? Is the fish farmed or wild? If it is from the seas, does it come from sustainable stocks?

* Take photos of what's available and post them on the intranet to start a debate.

* Contact your local hospital and ask if the community dietitian can analyse a week's menus to help raise the issues.

* For more info on changing food in the workplace, vist:

www.timesonline.co.uk/health

www.uscreates.com

www.bda.uk.com

www.sustainweb.org

www.whyorganic.org

www.bbc.co.uk/bigchallenge

Good Food in the workplace campaign: Does your workplace have any creative catering schemes or is its level of food unacceptable? Use the comment box below to tell us about your work canteen and ask questions to our online expert, Dr Amelia Lake, a research fellow at Newcastle University's Human Nutrition Research Centre.

Win an Organic Lunch Times Brain Box
Send us a review and photograph of your canteen food and you could win an Organic Lunch Times Brain Box full of healthy treats such as dried mango, fair-trade banana chips, herb oat cakes with pumpkin seeds, rosemary and thyme rice cakes, no-salt Duchy original oaten biscuits, date and walnut bar, sesame and honey snack bar, organic cherry cordial Hampstead, Earl Grey tea and Hampstead peppermint tea, apple puree and spreadable sunflower seed butter, delivered directly to your office from the Organic Delivery Company

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