Research led by a team at the University of Birmingham into 36 secondary schools in England (with 2273 pupils participating) and their compliance with the school food standards (SFS) showed limited compliance in both the schools mandated to comply (state-funded schools) and those not mandated to comply (academies and free schools established between 2010 and 2014). There is no external monitoring of compliance in England.

Compliance varied across standards. It was highest for those applying to lunchtime (median 81.3%) than those applying across the school day (median 41.7%). It was lower for high fat, sugar and energy-dense items standards (median 26.1%) than for those aiming to increase variety (median 92.3%). 

Using 24-hour recalls, the team found that pupils from SFS-mandated schools had a lower mean lunchtime intake of free sugar. There were few significant associations between percentage compliance and overall nutritional intake suggesting the wider food environment outside schools also needs addressing. 

The authors recognised limitations of the study including pausing data collection due to the COVID-19 pandemic, with only 46% of pupils providing two 24-hour recalls, and the limitations of self-reporting, especially in adolescents.