Food waste has a wide range of negative implications on the environment, economy and society and it is a concern for the catering industry and a growing percentage of the population. This work investigates the main root causes of food waste, in the catering industry, based on data collected from 32 businesses located in Wales, UK. The research uses multi-criteria decision making methods (Analytic Hierarchy Process and Decision Making Trial and Evaluation Laboratory), to analyse the degrees of importance and interrelationships of food waste enablers using holistic cause and effect diagrams and priority ranking. The analysis identifies critical food waste enablers in different dimensions (procurement and storage, processing, operation strategy, people and consumer) for various business outlets. Those causes can be addressed with limited resources and create the maximum value for the business and environment. The methodology could be used as a strategic tool by businesses in daily operations by managing and controlling identified root causes.