Objective: To investigate the resource efficiency and environmental impacts of producing one kilogram of edible protein from two plant- and three animal-protein sources.
Design: Primary source data were collected and applied to commodity production statistics to calculate the indices required to compare the environmental impact of producing 1 kg of edible protein from kidney beans, almonds, eggs, chicken and beef. Inputs included land and water for raising animals and growing animal feed, total fuel, and total fertilizer and pesticide for growing the plant commodities and animal feed. Animal waste generated was computed for the animal commodities.
Setting: Desk-based study at the Department of Nutrition and Department of Occupational and Environmental Health, Loma Linda University.
Results: To produce 1 kg of protein from kidney beans required approximately eighteen times less land, ten times less water, nine times less fuel, twelve times less fertilizer and ten times less pesticide in comparison to producing 1 kg of protein from beef. Compared with producing 1 kg of protein from chicken and eggs, beef generated five to six times more waste (manure) to produce 1 kg of protein.
Conclusions: The substitution of beef with beans in meal patterns will significantly reduce the environmental footprint worldwide and should also be encouraged to reduce the prevalence of non-communicable chronic diseases. Societies must work together to change the perception that red meat (e.g. beef) is the mainstay of an affluent and healthy diet.
Keywords: Animal protein; Plant protein; Resource efficiency; Sustainable agriculture.