A BBC survey of school meal uptake is expected to show numbers have fallen in England since the introduction of healthier school food at the start of the new term.
The results of the in-depth study, which are due to be released on Monday, are expected to paint a particularly negative picture in secondary schools, where the cafeteria-style culture at many has made introducing healthier alternatives a challenge.
The BBC compiled the report by questioning members of the Local Authority Caterers Association (LACA).
A source close to one local authority told Caterer: "It's the secondary schools that have been really struggling."
Other anecdotal evidence has suggested that numbers have remained largely flat or fallen year-on-year since the start of the new school year in September.
See next week's Caterer for reaction to the story.
By Tom Bill