The aim of the study was to assess the impact of different lunchbox messages on parents’ intention to pack a healthy lunchbox.

This study employed an experimental design.

A series of messages were developed to align with the six constructs of the Health Belief Model. Messages were also developed that were (and were not) personalised and varied based on the source of the information provided (university, school, dietitian and health promotion service). During a telephone survey, participants were read the content of each message and asked about their intention to pack a healthy lunchbox.

Parents of primary school-aged children were randomised to receive different messages to encourage the packing of healthy lunchboxes.

The study was completed by 511 parents. Linear mixed regression analyses identified significant differences (P < 0·05) in intention scores between variant messages targeting the same behavioural constructs for ‘susceptibility’, ‘severity’, ‘benefits’ and ‘barriers’ but not ‘cues to action’ or ‘self-efficacy’. The highest mean behavioural intention score was for ‘benefits’, whilst the lowest mean score was for ‘barriers’. There were no significant differences in intention scores of parents receiving messages from a dietitian, university, health promotion team or school (P = 0·37). Intention scores did not differ in which messages were personalised based on child’s name (P = 0·84) or grade level (P = 0·54).

The findings suggest that messages that focus on the benefits of packing healthy lunchboxes may be particularly useful in improving intentions of parents to pack healthy foods for their children to consume at school.

The present study describes the energy content of primary-school children’s lunchboxes and the proportion of lunchbox foods considered discretionary. Subgroup analyses by sex, socio-economic status, age and weight status were undertaken.

A cross-sectional study was conducted. Mean kilojoule content, number of items and categorisation of foods and drinks in lunchboxes as ‘everyday’ (healthy) or discretionary (sometimes) foods were assessed via a valid and reliable lunchbox observational audit.

Twelve Catholic primary schools (Kindergarten–Grade 6) located in the Hunter region of New South Wales, Australia.

Kindergarten to Grade 6 primary-school students.

In total, 2143 children (57 %) had parental consent to have their lunchboxes observed. School lunchboxes contained a mean of 2748 kJ, of which 61·2 % of energy was from foods consistent with the Australian Dietary Guidelines and 38·8 % of energy was discretionary foods. The proportion of lunchboxes containing only healthy foods was 12 %. Children in Kindergarten–Grade 2 packed more servings of ‘everyday’ foods (3·32 v. 2·98, P < 0·01) compared with children in Grades 3–6. Children in Grades 3–6 had a higher percentage of energy from discretionary foods (39·1 v. 33·8 %, P < 0·01) compared with children in Kindergarten–Grade 2 and children from the most socio-economically disadvantaged areas had significantly higher total kilojoules in the school lunchbox compared with the least disadvantaged students (2842 v. 2544 kJ, P = 0·03).

Foods packed within school lunchboxes may contribute to energy imbalance. The development of school policies and population-based strategies to support parents overcome barriers to packing healthy lunchboxes are warranted.