The purpose of this study is to adopt the urban metabolism method to compare bio-waste scenarios of reuse and landfills. The study focuses on food waste (FW) generated from Taipei City to determine what outcomes will result if bio-waste is transformed into energy or material resources. The results show that under the scenario of bio-waste reuse, metabolic efficiency in Taipei increases, e.g., the same amount of resources can be used to produce more products. However, the urban impact also increases due to the bio-waste conversion process. Applying the life cycle assessment method of quantifying the environmental burden for bio-waste conversion technology selection enhances the urban metabolism efficiency of resources in Taipei and reduces the urban impact on the environment. The most environmentally friendly FW conversion technology is composting after pre-treatment of high-temperature cooking. The next most environmentally friendly method is direct composting treatment. This is followed by anaerobic co-digestion with sewage sludge, and the worst option is transforming FW into bio-ethanol.