Effectiveness of an environmental nutrition and physical activity intervention in early childhood education and care settings (NAPSACC UK): A multicentre cluster randomised controlled trial

Background
Early childhood education and care (ECEC) provision is widespread. NAPSACC UK is an intervention in ECECs designed to improve nutrition and physical activity policies, practice and provision through ECEC staff workshops, self-assessment and assistance over one year. It was adapted for the UK from the USA and we tested whether it reduced energy consumption and increased physical activity.

Methods
Repeated cross-sectional, multicentre, two-arm, single-blind, parallel-group, cluster-randomised controlled trial including ECEC providers in the UK. The randomisation was conducted by a statistician who was blinded to ECEC provider identity, with allocation within each local authority area and by ECEC Index of Multiple Deprivation scores to minimise differences between arms. Participants were not blind to allocation. Co-primary outcomes after 12-months were child average total energy consumed per eating occasion in the ECEC (lunch or snack) and child accelerometer-assessed total physical activity on ECEC days. Secondary outcomes were moderate-to-vigorous physical activity, sedentary time, energy served and consumed at lunch and snacks, diet quality, and Body Mass Index z-score. The senior statistician and majority of co-investigators were blinded. Analysis was intention-to-treat. Trial registration is ISRCTN33134697 and is completed.

Findings
Between 14 March 2022 and 25 March 2024 we enrolled 52 ECEC providers (25 intervention; 27 control) and 835 2-5 year-olds (401 intervention, 434 control). The co-primary outcomes were assessed 12 months after baseline with data provided by 382 children for nutrition and 244 children for physical activity. There was no evidence of a difference in the co-primary outcomes compared to control of average kcal per eating occasion in ECEC (adjusted geometric mean ratio 0·86 (95%CI 0·72 to 1·03; p=0·09)) or total physical activity (adjusted mean difference (aMD) -2·13 minutes (95%CI -10·96 to 6·70; p=0·64)). There was evidence of lower lunch energy served (aMD -69·1 kcal per occasion (95%CI -116 to -22·2; p=0·004)) and consumed (aMD -67·7 kcal per occasion (95%CI -118·6 to -18·7, p=0·009)) with the intervention. There was no evidence of differences in other secondary outcomes. No adverse events were reported.

Interpretation
NAPSACC UK did not improve average kcal per eating occasion in ECEC or physical activity. Lower lunch energy servings and consumption closer to recommendations were observed as secondary outcomes. The lower fidelity to the intervention than intended and staffing pressures give insight into interpretation of the null result. Therefore, we recommend that policy-level and statutory changes, which require low agency by individual ECEC settings are research and policy priorities for nutrition and physical activity in ECEC.