The consumption of nutrients and food groups on days with or without school lunches was assessed among 5th grade elementary school students. The distribution of meals in one day was also compared. A cross-sectional study was conducted from October 2007 to February 2008 in Tokyo and Okayama. Weighing and observation were used to collect data on the school lunches, while dietary records by children accompanied by photographs were used to collect data on meals at home. The study lasted three days, two non-consecutive days with school lunches (weekdays) and one day without (Saturdays or Sundays). The subjects were 82 children with a normal obesity index. The consumption of calcium, vitamin B1, vegetables, and dairy products was significantly higher on the days with school lunches, while the consumption of salt and seasonings was significantly lower on the days with school lunches. The consumption of calcium, vitamin B1, and vitamin B2 at lunch accounted for a larger percentage on the days with school lunches. The results indicate that eating or not eating school lunches affected the consumption of nutrients and food groups for a child's entire day.