Kuroda et al. proposed a simple method for calculating the carbohydrate content based on a food exchange list (Shokuhin Koukanhyou), with a sugar content of dietary staples of 40 % for rice, 50 % for bread, and 20 % for boiled noodles and a side dish containing 20 g sugar. This study focused on the sugar content in in school lunches, which have a nutrient composition that is different from diabetic meals. The total energy content of school lunches and the sugar content in their side dishes were investigated in 42 school lunches served in elementary school. The average energy intake in the total lunch increased depending on the school grade (670±44 to 752±50 kcal; means±standard deviation). On the other hand, the sugar content of side dishes increased from 29.7±7.5 g in the 1^st-2^nd grade to 31.2±8.1 g in the 5^th-6^th grade, thus it could be estimated to be 30 g regardless of the energy intake. Two hundred milliliters of milk containing approximately 10 g of carbohydrate was served in every school lunch, which accounted for the 10 g increase in comparison to hospital lunches. These results indicate that the sugar content in the side dishes of elementary school lunches can be estimated to be 30 g regardless of the energy intake.