School food policy in secondary schools in England and its impact on adolescents' diets and dental health: the FUEL multiple-methods study.

Background: School food standards are a legal requirement for state-funded schools in England and are designed to promote healthy eating in pupils. However, state-funded academies/free schools established between 2010 and 2014 are exempt from this legislation. To complement the school food standards, the government launched the School Food Plan in 2013, which outlines voluntary actions that schools can take to support healthy eating and increase school meal uptake. There has been little evaluation of the school food standards and School Food Plan in secondary schools.

Objectives: To compare implementation and costs of the school food standards and School Food Plan, and pupil dietary and dental outcomes in two groups of secondary schools: those mandated and those not mandated to comply with the school food standards legislation.

Methods: An observational, multiple-methods study. We sampled state-funded secondary school academies/free schools, pupils aged 11-15 years, and school staff/governors with a role in food provision/education from the Midlands. We collected qualitative data in four schools. The primary outcome was pupil free sugar intake at lunch; across the school day; and during 24-hours. Secondary outcomes were additional nutritional outcomes and dental caries measures. We assessed school food standards/School Food Plan implementation and costs using researcher observation, document analysis, and surveys with staff/governors, schools and pupils. Dietary intake and dental outcomes were measured online using 24-hour dietary recall and surveys, respectively. In the qualitative study we conducted staff/governor interviews and pupil focus groups in a subsample of schools. We used multilevel analyses to explore variation in pupil outcomes across the school food standards-mandated and school food standards-non-mandated school groups. Data were analysed using the Framework approach.

Results: Thirty-six schools (13 school food standards-mandated, 23 school food standards-non-mandated), 2453 pupils and 151 staff/governors participated. On average, schools were compliant with 64% of school food standards and implemented 41% of School Food Plan actions, with no differences across school food standards-mandated/non-mandated schools. There was a wide variation in annual costs of the school food standards and School Food Plan reported by schools (mean of £195 per pupil). Pupils in school food standards-mandated schools had lower lunch intakes of free sugar than those in school food standards-non-mandated schools (adjusted mean difference = -2.78 g, 95% confidence interval -4.66 to -0.90 g). After further adjustment for total energy intake, there was no significant difference in free sugar intake, but the school food standards-mandated group had lower fruit and vegetable intake at all time points, and higher consumption of confectionery during the school day and sugar-sweetened beverages over 24 hours. There were no differences in dental outcomes between the two groups. Twenty-one staff/governors and 137 pupils participated in the qualitative study. Staff described balancing school food standards compliance with conflicting priorities related to financial viability. Some pupils felt that school food did not meet their needs for convenience, speed, value for money and taste, and disliked the lunchtime experience. Little time was afforded to healthy-eating education within the curriculum.

Limitations: There were large numbers of missing data for some study elements, including assessment of some School Food Plan actions and cost data.

Conclusions: In the secondary school context, the current school food standards are difficult to comply with and the School Food Plan has not achieved the desired outcomes. We found no evidence to show that school food standards legislation has positively influenced nutritional intake.

Future research: We need to develop healthy secondary-school food provision models that meet pupils' preferences, and better understand how to situate the food and healthy-eating agenda in secondary schools.

Trial registration: This trial is registered as ISRCTN68757496.

Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme (NIHR award ref: 17/92/39) and is published in full in Public Health Research; Vol. 12, No. 12. See the NIHR Funding and Awards website for further award information.