Making meat and milk from plants: A review of plant-based food for human and planetary health.

• Current commercial technologies limit the variety of plant-based meat forms, creating an obstacle for widespread substitution for the diverse assortment of animal meats. Plant-based milks may have wider acceptance as a fluid dairy milk substitute, as this is a specific type of dairy product. Less is known about adoption of other plant-based dairy products (e.g., yogurt and cheese). • Plant-based meats have lower environmental impacts compared to animal meat across several environmental indicators. The degree to which plant-based milks have lower environmental impacts than dairy milk depends on the indicator, plant-based milk comparator, and the functional unit. • Plant-based analogs do not completely mimic the nutrient composition of animal-source foods. While analogs may have better fat profiles, they may lack comparable protein and micronutrient compositions that are highly bioavailable in animal-source foods. • Future research on plant-based analogs should consider under which contexts direct substitution of ASFs are viable and have benefits or harms. This includes generating evidence on the role of trade and impacts on consumer diet patterns and health, and on smallholder producers livelihoods and welfare. Interest in alternative protein sources to substitute for animal source protein-rich foods has emerged alongside calls for sustainable food systems to meet protein demands as the global population grows towards a projected 9.8 billion people by 2050. Food companies are capitalizing on sustainable diet recommendations that encourage consumption of plant-based foods and have heavily invested in new plant-based foods that mimic animal source foods, effectively expanding the "plant-based foods" category. At the same time, globally there are two opposing protein transitions taking place as lower-income populations shift from plant to animal protein sources and higher-income populations that overconsume animal protein sources are recommended to shift towards plant-based foods. Using a global food systems lens, this review article builds on existing literature to assess the extent to which plant-based meat and milk analogs can become part of sustainable diets across two competing protein transitions and to identify unresolved knowledge gaps. This articles first examines global meat and dairy consumption trends as well as the emergence of plant-based analogs and consumer perceptions. We then draw on the literature to compare the environmental footprints and nutrition compositions of plant-based meats and milks against their respective conventional equivalents. We find that, while there are promising environmental benefits to substituting meats and milk with certain plant-based analogs, the uptake of these products is likely stifled based on the small number of products they mimic (i.e., ground meat, meat emulsions, meat crumbles, and fluid milk). Further, plant-based analogs do not completely mimic the nutrient composition of animal source foods. Plant-based analogs may have improved compositions, such as improved fat profiles. However, analogs may lack comparable protein and micronutrients that are highly bioavailable in animal source foods. Care should be considered for plant-based analogs that inherently fall under the "plant- based food" category as they are vastly different from whole and minimally processed plant foods and the intended benefits of plant-based food consumption may not be generalizable. Future assessments of meat and milk analogs should consider under which contexts direct substitution of animal source foods are viable from a consumer standpoint and examine both environment and nutrition impacts that are important to the given population. [ABSTRACT FROM AUTHOR]