Aramark's "Just 4U" food service programme divides menu choices into the following headings: Low Fat, Heart Healthy, Carb Counter, Cal Smart, Vegetarian, and Vegan.
In a survey of 100,000 US college students conducted by Aramark, 24% said vegan dishes were important to them, while 18% wanted low-carb dishes on the menu.
Sodexho also believes that functional foods, such as those that help reduce cholesterol, will be an increasing feature in menus of the future. Contract catering giant Compass reckons that a desire for healthy fresh foods means that more clients will want juice and smoothie bars.
The grab-and-go and snack market will continue to develop, and there will be a need to create more healthy hand-held snacks - these are becoming more significant in terms of their menu share and spend. Almost half of workers fork out £3.10 a day on snacks, considerably more than they pay for lunch - on average, just £2.02 a head, according to the Eurest Lunchtime Report.
Working lunches have changed over the years from four-course affairs to ones involving minimal disruption. But they also need to provide enough food to help busy executives make it through an all-day meeting.
Rob Kirby, group executive chef for Avenance, reckons that service formats that are easy to set up and clear away will become more popular.
This means that sharing platters of hot or cold items, such as mini-kebabs or sushi, and bowl food will continue to be favourites, along with hot items that can be served in small steamer baskets. Bento boxes won't be used just for Japanese fare, he says, but for other choices as well, such as Caprese salad and seared red mullet.
Ian McAndrew, culinary director of the In House Catering Company, predicts that dried fruit, nuts and muesli bars will replace biscuits during breaks.
Kirby also points to the success of Pret A Manger's take-away sandwich service, showing that for some clients the humble sarnie remains at the top of the pile.
He also warns caterers not to miss out on the growing demand for breakfast food to accompany breakfast meetings. Watch out for a new phenomenon in City offices - detox breakfasts, which include fruit or herb shots.
Global flavours will continue their march on menus. In particular, watch out for Latin American dishes, which will be a "hot" flavour this year, according to Aramark, which will run a Brazilian promotion early in the year. Sodexho reckons it has identified a growing interest in Mexican and Thai dishes, and Compass division Restaurant Associates plans to expand menus to offer North African and Caribbean food.
In suitable units, Aramark will run a Fairtrade Fortnight in March and an Organic Festival later in the year. Compass business development director for business and industry, Debi Siegenberg, agrees that Fairtrade is becoming increasingly important for many major clients. Some Government contracts require Fairtrade to be part of the offering.
Both large and small contractors think that although customers are interested in organic food they are still not prepared to pay extra for it. Blue Apple introduced a totally organic salad bar at the request of one client last year, but the response was average. Joint managing director Ruston Toms says customers continue to mistake the imperfect appearance of organic produce for inferior quality.