Animal and plant-sourced nutrition: complementary not competitive

Abstract

Debate on the sustainability of the global food system often compares the environmental, economic and health impacts of plant-and animal-sourced foods. This distinction can mask the considerable variation in impacts across and within these food groups. Moreover, the nutritional benefits of these food groups are insufficiently discussed. In this review, we highlight the nutritional contribution to the current global food system of both plant-and animal-sourced foods and place their impacts on human health in the global context. We highlight how the comparison of the environmental impacts of foods via life cycle analyses can change on the basis of the functional unit used, particularly the use of mass as opposed to nutrient content or nutrient richness. We review the literature on the affordability of nutrient-adequate diets, demonstrating the presence of both plant-and animalsourced foods in affordable nutritious diets. Finally, we address the potential of alternative food sources that are gaining momentum, to ask where they may fit in a sustainable food system. We conclude that there is a clear place for both plant-and animal-sourced foods in future sustainable food systems, and a requirement for both for sustainable global nutrition; as such, the two groups are complementary and not competitive.

Diets with Higher Vegetable Intake and Lower Environmental Impact: Evidence from a Large Australian Population Health Survey

“…In other words, this was an a priori modeling decision by the researchers. Our finding that adult diets in Australia with a higher vegetable intake and lower environmental impacts had more red meat and fewer grains supported the view that animal- and plant-sourced nutrition should be viewed as complementary, not competitive [ 71 ]. These results underscored the importance of examining the complete diet, including the local context that determines the interrelationships between the various types of food eaten in meal combinations.…”

Evaluation of nutritional quality of complementary foods formulated from blends of Nigerian yellow maize (Zea mays), soybean (Glycine max) and crayfish (Procambarus clarkii)

“…Conversely, the protein of soybean is a relatively rich source of tryptophan but has a limiting sulphur‐containing amino acids 45 . Crayfish, being an ASF, is rich in sulphur‐containing amino acids and therefore can complement diets formulated with soybean as a component 47 . The sulphur‐containing amino acid in crayfish was approximately 3758% and 1186% higher than those of MF and SBF, respectively (for the essential amino acids composition of MF, SBF and CRF, see Table A5).…”

Nutritionism in a food policy context: the case of ‘animal protein’

“…Scrinis 2013). Depending on the context, this may imply that animal:plant ratios are altered, but decisionmaking should at all times resist the oversimplification of this problematic binary categorisation (Smith et al 2021). Moreover, we contend that animal-source foods should not be reduced to the quantity of protein they provide, but rather appreciated for their high density in numerous bioavailable nutrients, many of which are difficult to obtain in adequate quantities through plant-source foods alone and vice versa.…”

“…A second consideration is that a narrow focus on CO 2 -eq and land use per unit of nutrition (even on the hypothetical condition that this would be properly expressed) risks overlooking various contextual factors (Smith et al 2021). This is related to the use of global averages masking large regional and even local variations in efficiency, a difference in global warming between CO 2 from fossil fuels and biogenic methane from ruminants, poor suitability of marginal land for crop agriculture, often failing to account for soil carbon stock changes (for better or worse), the amount of existing woodland on a farm, which will be actively capturing carbon from the atmosphere, lack of accountancy for co-products, etc.…”