Systematic Review of Dietary Patterns and Sustainability in the United States

Abstract

Improving awareness and accessibility of healthy diets are key challenges for health professionals and policymakers alike. While the US government has been assessing and encouraging nutritious diets via the Dietary Guidelines for Americans (DGA) since 1980, the long-term sustainability, and thus availability, of those diets has received less attention. The 2015 Dietary Guidelines Advisory Committee (DGAC) examined the evidence on sustainable diets for the first time, but this topic was not included within the scope of work for the 2020 DGAC. The objective of this study was to systematically review the evidence on US dietary patterns and sustainability outcomes published from 2015 to 2019 replicating the 2015 DGAC methodology. The 22 studies meeting inclusion criteria reveal a rapid expansion of research on US dietary patterns and sustainability, including 8 studies comparing the sustainability of DGA-compliant dietary patterns with current US diets. Our results challenge prior findings that diets adhering to national dietary guidelines are more sustainable than current average diets and indicate that the Healthy US-style dietary pattern recommended by the DGA may lead to similar or increased greenhouse gas emissions, energy use, and water use compared with the current US diet. However, consistent with previous research, studies meeting inclusion criteria generally support the conclusion that, among healthy dietary patterns, those higher in plant-based foods and lower in animal-based foods would be beneficial for environmental sustainability. Additional research is needed to further evaluate ways to improve food system sustainability through both dietary shifts and agricultural practices in the United States.

Environmental and nutritional analysis of the EAT-Lancet diet at the individual level: insights from the NutriNet-Santé study

“…In contrast, a recent review focusing on analysis of sustainability of dietary guidelines for Americans reported that healthy US dietary patterns may be responsible for similar or higher GHGe, energy and water use compared to current US diets (Reinhardt et al, 2020). The review study also underlined, as expected, that plant-based dietary guidelines may only contribute to limit environmental pressures related to food systems.…”

Adherence to the Mediterranean Diet and Environmental Impact of the Diet on Primary School Children Living in Parma (Italy)

“…A trade-off between maintaining health and the environmental dimension of human diets has been reported in the literature. In this regard, a newly published systematic review found that adhering to the national dietary guidelines does not ensure eco-friendlier diets compared to the current average US diet [ 37 ]. Similarly, an improvement in the environmental performance was not necessarily associated with diet adequacy in terms of energy and nutrients considering national data of the adult populations of five European countries (Finland, France, Italy, Sweden, and the UK) [ 38 ].…”

The importance of food systems and the environment for nutrition

“…A growing body of literature takes an even broader view on dietary patterns, assessing their associations with not only human health but also environmental impacts including GHG emissions, land and water use, and biodiversity ( 65–67 ), and the EAT– Lancet Commission Report represented an attempt to find synergies between healthy diets and sustainable food production at a global level ( 1 ). Research on the sustainability of various dietary patterns increasingly highlights the existence of both co-benefits and trade-offs between nutrition and environmental impacts ( 68 , 69 ). Although some research has shown that diets which rely mostly on plant-based sources have lower GHG emissions, reduced deforestation, and decreased water footprints (especially in HICs) ( 1 , 65 ), in many LMIC contexts improving nutritional status may benefit from a focus on adequate nutrients with more inclusion of animal source foods in the diet, which may be accompanied by an increased environmental footprint ( 70 ).…”