School meals are already becoming healthier with a sharp decline in canteens ordering chips, chocolate and frozen turkey, according to new figures.

The reduction in fatty and unhealthy foods being supplied to schools by catering wholesalers predates TV chef Jamie Oliver's campaign, said market research company ACNielsen.

Figures showed fewer frozen chips were supplied to schools in the year to March 12, compared with the previous year, with sales down by £521,000.

And frozen turkey sales were also down by £463,000.

Chocolate sales were £267,000 lower than last year, while frozen burgers and sausage rolls were both down by about £150,000.

Eleni Nicholas, managing director of ACNielsen UK said the figures were evidence of "a clear move away" from unhealthy food.

"Following a year of constant media interest in health and obesity in children it seems that the sector has already begun to re-evaluate what is being served to our children."

The figures showed healthier food had also increased in popularity.

Still water sales were up by £230,000, while, drinking yoghurt, chilled fruit and vegetables and natural frozen fish sales also rose.

Oliver's hit TV series Jamie's School Dinners brought the issue of school meals to the heart of the education debate in the run up to the General Election.

The chef's Feed Me Better campaign included a petition to Downing Street which attracted 271,000 signatures.

Ministers announced a £280 million package of investment into school meals, including a new panel of experts to offer advice and extra money for ingredients.

New rules are due to come into force aimed at cutting levels of salt, sugar and fat in processed foods served in schools, including burgers and cake.