In this paper, we seek to understand how wastes occur, in the food service industry. Different business units, from a large restaurant chain, were longitudinally analyzed.Considering the fact that more players operate in this growing Brazil industry, invariably it brings the need for greater efficiency, in the medium term. In this sense, the impact of losses or waste on corporate profits, according to industry indicators, is still quite significant, since they occur during all steps of the production/sales chain. This situation reveals the existence of an opportunity to increase the efficiency on the operation's field. Waste's measurement method applied in this research was the difference between the theoretical cost and the actual cost, based on successive inventory counts. The selection of the candidates' predictive variables was supported, mainly, by the Sociology and Economics of Strategy fields. After the application of a panel data regression technique, variables related to the store´s physical format, employees profile and the unit main manager's socio-demographic were found significant to explain different levels of waste.