A quarter of pupils at schools in Redbridge, Essex, have turned their noses up at healthier school meals, according to caterer Eden Foodservice.
The 25% drop is more than double the national average.
A spokesman for Eden Foodservice, which was formerly Initial Catering, said: "We've had to adhere to the Government standards, but basically they've had a bigger impact in Redbridge than anywhere else."
A BBC survey this week and Caterer research showed that since September school- meal take-up in English schools had fallen by anything up to 10% compared with last year.
Many local authorities contacted by Caterer conceded their school meals service was in the red and questioned the long-term viability of a council-run service.
Paul Doherty, headmaster of Nightingale primary in Redbridge, said: "School dinners are often run by outside caterers. My view is, if school dinners are so important why don't we have a national dining service?"
An Eden Foodservice spokesman said: "We believe the drop is primarily due to children adjusting to unfamiliar dishes and the wide demographic we are catering for."
By Tom Bill