This study is aimed to evaluate and compare environmental impacts of various food waste management systems: anaerobic digestion, co-digestion with sewage sludge, and volume reduction using a garbage dryer followed by incineration from generation to final disposal. An environmental credit using life cycle assessment was employed to compare by-products. The entire disposal process, namely discharge, collection, transportation, treatment, and final disposal, was included in the system boundary. The functional unit was 1 tonne of food waste from households for each treatment option. Global warming potential of the category indicator was selected to assess the environmental impact of food waste disposal options. The net global warming potential (environmental credit) of the options (wet based) was 33 kg of carbon dioxide equivalent (CO₂-eq) for anaerobic digestion and -315 kg of CO₂-eq for incineration by renewable energy production as electricity, thermal energy, and primary materials avoided. We found that dryer-incineration option was an available alternative for food waste recycling in a metropolitan area in Korea.