OBJECTIVE: To assess the effectiveness of lunchbox interventions aiming to improve the foods and beverages packed and consumed by children at centre-based care or school; and subsequent impact on children's adiposity.

METHODS: Systematic search of nine databases for controlled trials published in English between 1995-January 2017. Where appropriate, data were pooled in a random effects meta-analysis.

RESULTS: Of the 1601 articles identified, ten studies (centre-based care n = 4, school n = 6) were included of which eight were RCTs. The impact of interventions on the packing of discretionary foods, sugar-sweetened drinks and other core foods was inconsistent. Meta-analysis of four RCTs trials found a moderate increase in provision of vegetables (SMD = 0.40 95% CI 0.16 to 0.64, p = 0.001, I2 = 82%; equivalent to a mean difference of 0.28 serves) but not fruit. Four studies reported impact on children's dietary intake, one reported no significant effect on consumption of discretionary foods, one reported improvements in the consumption of sugar-sweetened drinks and water, and two reported improvements in consumption of vegetables and fruit. Two studies, that were broader obesity prevention interventions, reported no significant impact on adiposity.

CONCLUSIONS: There is some evidence that lunchbox interventions are effective in improving the packing of vegetables in children's lunchboxes, however more robust research is required to determine the impact on children's dietary intake and adiposity.

TRIAL REGISTRATION: PROSPERO 2016: CRD42016035646 .