There are several different metrics used to measure sustainability. Given the limited and depleting amount of fresh water sources, looking at the amount of water used to produce specific crops is one measure of sustainability, albeit an imperfect one. For example, the data suggests that on average, it takes a substantially larger amount of water to produce a serving of beef than a serving of strawberries. But surviving on beef is a lot easier than surviving on strawberries. Gram per gram, beef provides five times as many calories as strawberries or brussels sprouts, plus protein is an essential nutrient. While choosing food types based on water requirements may create nutrition challenges, substitutions within a food type may bring other c...