Recent years have seen increasing global interest in the study of food loss and waste, and their related environmental impacts. Wasted food creates carbon emissions throughout the duration of the food supply chain, from agricultural production, food processing, and distribution, to consumption and waste disposal. While it is widely known that the generation of food waste must be reduced, the lack of quantitative information on the production of household and catering food waste has led to the underestimation of waste volumes and hampered the development of proper policy interventions designed to decrease food waste. This study investigated the volume of catering food waste generated in Beijing and calculated its carbon footprint. In this study we focused on avoidable food waste, i.e., all wasted food and raw materials that could have been consumed had they been prepared differently. Other bio-wastes, such as vegetable peelings, bean dregs, or bones, were not measured. During first-hand surveys of the catering sector of urban Beijing in 2013, 136 restaurants were studied. These establishments can be divided into large, medium, small, canteen, and fast food restaurant categories. A total of 2704 samples were collected, each consisting of two parts:a consumer questionnaire, and the weight of each sample consumer's food waste generated by the establishment. The greenhouse gas emissions produced during each stage of the food supply chain were calculated, and then scaled up using the restaurant data to determine the total quantity of carbon emissions produced by the production of catering food waste in Beijing. The main conclusions of this study are as follows:(i) The total amount of food waste generated by the Beijing catering industry is 39.86×10⁴ t/a, or about half of the total weight of food consumed in Beijing. (ii) The food waste was comprised of many different food types, the most prominent (by weight) being vegetables (43.16%), followed by aquatic products (10.51%), pork (8.79%), wheat flour (7.35%), beans and bean products (7.19%), poultry (6.93%), rice (6.09%), other grains (3.20%), mutton (1.94%), eggs (1.84%), beef (1.70%), other meat (1.23%), and dairy products (less than 1%). (iii) The total carbon footprint of the catering food waste produced in Beijing was 192.51×10⁴-208.52×104 t CO₂ eq. By food category, the largest proportion of the calculated total carbon emissions was generated by meat (61.76%), vegetables (25.09%), and grains (11.30%). By process, the food production stages producing the largest proportions of the emissions are agricultural production (almost 50%), catering consumption (37.39%), and waste management (13.68%).These results reveal clear differences between the distribution of waste and the carbon footprint of different wasted products. Although food waste can be more accurately quantified in terms of mass or value, these metrics does not provide sufficient information about its potential environmental impacts. Therefore, analyzing food waste in terms of both wasted mass and the carbon footprint of the wastage is a better means of identifying priority targets for the development of efficient waste reduction measures.