Background There is limited evidence on diet and physical activity (PA) interventions to prevent childhood over- and under-nutrition in Nigeria, and none focused on parental involvement. Knowledge of socio-cultural and environmental contexts, prioritising views of target populations, is needed to inform intervention strategies. The aim of this study was to explore parents, children and other stakeholders’ views on the factors that might enable or hinder participation in diet and PA interventions and parental involvement, and potential intervention components likely to be feasible and acceptable.

Methods A grounded theory, qualitative cross-sectional study was conducted in culturally diverse local government areas of Lagos State, Nigeria. Participants were identified through purposive and theoretical sampling, and data collected over three iterative phases. Eleven boys and girls aged 8–11 years; 19 women and 14 men aged 19–60 years who were parents, teachers/school heads, community leaders, health workers, and health or education civil servants, took part in 25 semi-structured one-to-one interviews and three focus groups. Discussions were digitally recorded and transcribed verbatim. Manual thematic analysis and independent coding of the transcripts generated key themes and reduced bias in the analysis.

Results Three overarching themes were identified: 1. Active community collaboration 2. Strategies for involving families; and 3. Schools as key settings for interventions. Adult participants voiced active partnership between communities and schools as essential to addressing barriers to diet and physical activity interventions, such as inconsistent funding and lack of safe outdoor space for PA. Children reported concerns about school meal quality and poor access to clean water and menstrual hygiene products impacting PA participation. Suggested solutions achieved by community partnerships included security for outside play areas, and infrastructure improvements using recycled/locally sourced materials, and health campaigns funded by local dignitaries. Suggested activities for engaging families in interventions included health literacy teaching for parents, using learning aids tailored to literacy levels and local dialects, and involving religious leaders.

Conclusion This study highlighted the challenges for consideration in childhood diet and PA intervention development in Nigeria. The feasibility and acceptability of grassroots suggestions for intervention components and parental involvement could usefully be explored in future pilot studies.