Household Income Is Associated with Food and Nutrient Intake in Japanese Schoolchildren, Especially on Days without School Lunch

Background/Aims: The study aimed to examine the association between household income and the intake of foods and nutrients of Japanese schoolchildren, and any differences between days with and without school lunch. Methods: This was a cross-sectional study. Children, with the support of their parents, kept dietary records with photographs for 4 days (2 days with school lunch and 2 days without). The socio-economic status of each family was obtained from a questionnaire completed by the parents. All students in 5th grade (10–11 years old) at 19 schools in 4 prefectures and their parents (1,447 pairs of students and parents) were invited to take part in this study; 836 pairs of complete data sets were analyzed. Results: The average results of 4 days of dietary records showed that lower income level was associated with a lower intake of fish/shellfish, green vegetables, and sugar at the food group level, a lower intake of protein and several micronutrients, and a higher energy intake from carbohydrates at the nutrient level among the children. These associations between income and food/nutrient intake were not significant on days with school lunches, but were significant on days without school lunch. Conclusion: Our study confirmed an association between household income and amounts of foods and nutrients consumed by Japanese schoolchildren, and suggested that school lunches play a role in reducing disparities in the diets of children from households with various incomes.