Nutrient availability in urban food waste: carbohydrate bias in the Philadelphia–Camden urban matrix

Urban areas provide animals with both a unique set of challenges and resources. One of the novel resources available in urban areas is an abundance of human food waste. Although it is known that many urban-dwelling animals are consuming human food waste at some level, there is not a good understanding of the nutrients provided by this novel resource. Given that human food waste is unlikely to resemble an animal’s natural diet, there could be health consequences for an animal consuming human food waste. In some animals, nutritional imbalances can also lead to behavioral changes, making it important to understand more precisely what they are eating. To answer the question of what nutrients were available in urban food waste, we surveyed food waste in the Philadelphia–Camden urban matrix. We found that human food waste contained ∼1000% more carbohydrates than other nutrient types. Given the impact that carbohydrate-rich diets can have on human health, there may be important consequences for the animals in urban environments that consume this food waste. Therefore, it is possible that human food subsidies have cascading consequences for entire communities and their ecosystem services in cities.