According to data provided by FAO from 2011. almost one-third of total food produced for human consumption remains unused and end up as waste mass [1]. The aim of this research is to collect data on the amount of food left after meals in elementary school canteens in the Osijek-Baranja County and to use the collected data to improve diet nutrition management. Considering several ways and variables in selecting the appropriate quantification method for this type of measurement, a simple equation was used, the difference between mass of the meal before the dining and mass of the leftovers. According to HZZ data, the unemployment rate in Osijek-Baranja County is exceptionally high and the average incomes are lower than the average of most Croatian counties [2]. The provided finance for nutrition in elementary schools can be better utilized to improve meal quality rather than financing waste. Collected data would be a good basis for raising awareness of the value of food in primary schools. Education in young age can help to raise responsible people who will have knowledge of their impact on economic, social and environmental aspects.