Parents who have no time to prepare sandwiches for their children are increasingly relying on shop-bought fare. In the wealthier areas of Britain, signs have appeared in delicatessens and coffee shops advertising a children's lunch service. On offer are treats such as stuffed ciabatta, seedless grapes and fresh fruit milkshakes - costing as much as pounds 7 a day and often provoking classroom rivalry.
In Kensington, west London, The Pie Man sandwich shop offers a school packed lunch for pounds 6.99. It contains four different sandwich triangles, a scotch egg, sausages, fruit and an array of little biscuits.
In Hampstead, north London, a coffee bar called The House is doing a roaring trade with a slightly cheaper deal. "We offer a school packed lunch for pounds 3.75," said "Christian". "The children can have a sandwich, a soft drink, a piece of fruit and a packet of crisps."
Andrea Lowell, who teaches infants at a neighbouring independent day school, has noticed the trend. "Lunches are always a big topic of conversation and even of teasing," she said, adding that children were often disappointed by the contents of the pack they had been bought. "Children are creatures of habit. They don't seem to have the same need for variety that adults have and they prefer the same biscuit or sandwich spread every single day."
Beyond the privileged neighbourhoods of London, other parents are far from impressed with the latest attempt to make a living from the requirements of schoolchildren.
Gill Fairhall, from Portsmouth, who has three children, said: "Everyone has to live their life in their own way, but it does seem extravagant. I prepare packed lunches every morning. I buy in bulk and keep stores in the cellar, so the children can have a little variety."
Mrs Fairhall, a full-time mother, says she would be happy to make packed lunches even if she had paid work. "It only takes five minutes and it is just a question of making the time," she said.
Her nine-year-old daughter Pippa usually takes a filled bagel to her Church of England school in Old Portsmouth, along with a sausage roll, a packet of crisps and a cake.
Connor Dawson, six, who attends a state school in neighbouring Havant, has less adventurous tastes. He takes Marmite sandwiches and a packet of crisps to school every day and accepts nothing else.
Ten-year-old Adam Chambers, who goes to Ditcham Park, an independent school in Petersfield, is used to a lunch of a sandwich, a yogurt, a piece of fruit and a sweet, prepared each day by his mother Gina. "There seems to be a lot of competition between the boys," she said. "Adam sometimes comes home with an entirely different wrapper in his lunchbox and tells me he swapped."
Sampling the contents of five shop-bought packed lunches, Pippa, Connor and Adam were unanimous. They all swooped on the sweetest food first and, perhaps predictably, turned up their noses at a stylish Sashimi raw fish selection. "I think I'll pass," said Pippa.
Even The House's avocado- and-chicken sandwich was a little too exotic for this panel, as was a ciabatta roll filled with tomato and mozzarella. "I think Pippa was put off by the fact it was cold," her mother said. "At home she is used to ciabatta that has been warmed."
The sausages in the pounds 6.99 lunch were universally approved of, as were the crisps and chocolate biscuits.
"Adam's school doesn't really approve of chocolate," Mrs Chambers said. "It was a bit of a novelty for him."
Parents who wish to pamper children now accustomed to pesto and avocado do still have an option in reserve for special occasions. Fortnum & Mason in Piccadilly offers a child's tuck box containing Cox's orange pippin biscuits, a tin of drinking chocolate, a banana, a pot of lemon curd, ginger biscuits and bon-bons for only pounds 55.