Abstract
BACKGROUND: In September 2023, Tower Hamlets implemented a major policy change to Universal Free School Meals (UFSM) extending provision to all secondary school pupils aged 11-16y. There is limited evidence exploring the effects of UFSM in secondary school-aged children, and this, therefore, offered an opportune natural experiment to explore the effects of this policy change. The aims of the project were to explore the effects of UFSM on secondary-school aged pupils' dietary intake and food security. METHODS: Natural experiment using a mixed longitudinal cross-sectional design in intervention (n = 3) and control schools (n = 2). Schools purposefully selected Year 8 classes and all pupils were invited to participate using opt-out consent. Pupils completed four non-consecutive weekdays of total dietary intake using Intake24. Dietary outcomes were mean change in key macro- and micronutrients pre-post-UFSM at lunchtime and in total diet. Within-pupil changes were analysed using a linear model that adjusted for gender and included a lunch-type and intervention/control interaction. RESULTS: Dietary data pre- and post- UFSM was captured for 176 pupils (99 intervention, 77 control). Only a small number of pupils in the intervention schools changed lunch-type to take up UFSM (n = 19). Most pupils had a combination of School, Home or Other lunch. Only two of the 18 tests for interaction gave p < 0.05, namely energy and protein intakes at lunchtime. Most pupils were food secure both pre- and post-UFSM in intervention and control schools. CONCLUSION: Although we found almost no lunch-type and intervention/control interaction effects on mean change in pupils' dietary intakes, inferences about dietary effectiveness require careful consideration. Reasons include only a small number of pupils took up the UFSM offer, there may be a delay between implementation and take-up, and we do not know how the offer of UFSM was communicated to parents and/or pupils. This study highlights a need for better understanding of reasons for poor take up and whether take up will change over time post policy implementation. Wider challenges pertinent to school food, such as, the quality and availability of food on offer, and the dining environment, remain important considerations to maximise the nutritional benefit of universal free school meal policy changes.