Uneaten food, whether by patients or unserved, is considered food waste. Plate waste is the remaining, uneaten food after being served to patients in the hospital. The uneaten food has a cascading environmental impact on increasing the amount of food grown or raised, energy in transport of food to hospitals, and impact of methane and carbon dioxide from landfilling the uneaten food. Food waste has been measured either by weight or visual estimation. About 500 hospitals worldwide have had food waste studies and about half are in Europe. This study is the first to quantify the limited data on different strategies for improving food waste results. There were 92 studies that documented improvement of food waste, with the single biggest change being tailoring the food choice to the individual patient's desire for food. Unserved food waste was not considered in this review.