The expansion of sandwich bars and the trend for healthy eating has turned sluggish performance in the sandwich market between 2002 and 2006 into an estimated 9% rise in the last year, says a new report.

Research from Mintel estimates the market will be worth more than £4 billion this calendar year, up from £3.3bn in 2002. And it forecasts a 27% expansion between 2007 and 2012, taking sales to around £5.2bn.

Vivianne Ihekweazu, senior market analyst at Mintel, said: "The sandwich market has turned itself around. Having successfully tapped into the trend for healthy eating, it is now clearly reaping the rewards." The availability of superfood and wheat-free varie-ties, coupled with a greater range of fillings, helped to boost sales.

But the Mintel report, entitled Sandwiches, published last week, warned that "after three to four years, the focus will need to be a continuous increase in value sales, as the competitive environment - both within the sandwich category and outside it - is becoming very intense". It added: "More consumers may choose salads and fewer carb-rich options, as health becomes a major focus. The amount of salt in these products may also come under increasing scrutiny."

Takeaway sandwiches dominated the market, accounting for £3.8bn-worth of sales in the last year, said Mintel, while eat-in sales represented just 6% at £229m.

Mintel also found a change in adults’ bread preferences, with white bread down from 65.3% in 2003 to 52.4% in 2007. Meanwhile healthier types were increasingly favoured, with brown up 5.9%, Granary up 6.5% and wholemeal up 7.6% over the same period.

’Eat me, keep me’ deals, where one sandwich is bought for immediate consumption and another to keep and eat later, could make the most of the trend towards longer working hours, added the report.