Objective: Nutrient and food standards exist for school lunches in English primary schools although packed lunches brought from home are not regulated. The aim of the present study was to determine nutritional and dietary differences by lunch type.Design: A cross-sectional survey was carried out in 2007 assessing diet using the Child and Diet Evaluation Tool (CADET), a validated 24 h estimated food diary. The data were analysed to determine nutritional and dietary intakes over the whole day by school meal type: school meals and packed lunches.Setting: Fifty-four primary schools across England.Subjects: Children (n 2709) aged 6-8 years.Results: Children having a packed lunch consumed on average 11·0 g more total sugars (95 % CI 6·6, 15·3 g) and 101 mg more Na (95 % CI 29, 173 mg) over the whole day. Conversely, children having a school meal consumed, on average, 4·0 g more protein (95 % CI 2·3, 5·7 g), 0·9 g more fibre (NSP; 95 % CI 0·5, 1·3 g) and 0·4 mg more Zn (95 % CI 0·1, 0·6 mg). There was no difference in daily energy intake by lunch type. Children having a packed lunch were more likely to consume snacks and sweetened drinks; while children having a school meal were more likely to consume different types of vegetables and drink water over the whole day.Conclusions: Compared with children having a school meal, children taking a packed lunch to school consumed a lower-quality diet over the whole day, including higher levels of sugar and Na and fewer vegetables. These findings support the introduction of policies that increase school meal uptake. [ABSTRACT FROM AUTHOR]