After the attack on turkey twizzlers, now packed lunches come under fire for making schoolchildren fat Packed lunches are making children fat, government food advisers say School dinners are healthier than 'sandwiches, crisps and fizzy drinks' Report on school dinners to be published this week Parents who make packed lunches for their children should stop, as it is making them fat, government food advisers warn. Restaurateurs Henry Dimbleby and John Vincent argue school dinners are healthier than packed sandwiches, crisps and fizzy drinks, in a report to be published next week. The report will also suggest that take-up must rise to at least 50 per cent to improve nutrition in meals and to save school dinners. Bad food: Packed lunches are making school children fat and parents should instead pay for their children to have school dinners, two government advisers say The co-founders of restaurant chain Leon have spent a year visiting more than 60 schools in the UK and say school dinners are "miles better" than when celebrity chef Jamie Oliver began his war on Turkey Twizzlers in 2005. "Many parents mistakenly believe their child is better off with a packed lunch," the restaurateur's write in the Sunday Times. For the sake of the nation's health we want parents to switch to school meals. The pair argue that the fact that 20 per cent of children are obese by the time they leave primary school is a direct result of more than half bringing packed lunches or buying food outside of school. Anti-obesity drive: Leon fast food chain founders John Vincent (left) and Henry Dimbleby (right) want pupils to be banned from bringing in packed lunches or leaving the premises at lunchtime Lunchtime: There are no signs of Turkey Twizzlers and meals have improved over the past decade The pair's school lunch plan, which will be launched this week alongside education secretary Michael Gove, also puts it down to head teachers to improve quality and take-up of school lunches. "A lot of heads will feel exasperated by this," Ian Bauckham, head of Bennett Memorial Diocesan school in Tunbridge Wells, Kent told The Sunday Times. Many focus on a limited number of high priorities and we already have a big agenda to raise academic standards. As reported earlier this year, cooking lessons at school will become compulsory for children ages seven to 14 from September as the Government aims to ensure they can make up to 20 dishes before taking their GCSE exams. Crusade: Jamie Oliver on the 2005 show 'Jamie's School Dinners' which led to a Government pledge to improve food for school children Leon fast food chain founders Henry Dimbleby and John Vincent were tasked last year by Mr Gove, 45, with moving on the campaign for better school meals begun by celebrity chef Jamie Oliver, 37. They suggest parents should spend the £1.2billion that annually goes on packed lunches on school meals instead, and double the take-up percentage over five years, reported the Sunday Times. Mr Dimbleby and Mr Vincent's chain has 13 restaurants in London and the South East, specialises in burger, chicken and fish dishes and has an emphasis on sustainability and providing good nutrition. Jamie Oliver's 2005 crusade led to the Feed Me Better campaign, after which then Prime Minister Tony Blair promised to take steps to improve school dinners. It saw the creation of the School Food Trust, which saw £60million spent on education and support for school administrators to improve foods in schio