Improving diet sustainability through evolution of food choices: review of epidemiological studies on the environmental impact of diets

Abstract

The Food and Agriculture Organization defines sustainable diets as nutritionally adequate, safe, healthy, culturally acceptable, economically affordable diets that have little environmental impact. This review summarizes the studies assessing, at the individual level, both the environmental impact and the nutritional quality or healthiness of self-selected diets. Reductions in meat consumption and energy intake were identified as primary factors for reducing diet-related greenhouse gas emissions. The choice of foods to replace meat, however, was crucial, with some isocaloric substitutions possibly increasing total diet greenhouse gas emissions. Moreover, nutritional adequacy was rarely or only partially assessed, thereby compromising the assessment of diet sustainability. Furthermore, high nutritional quality was not necessarily associated with affordability or lower environmental impact. Hence, when identifying sustainable diets, each dimension needs to be assessed by relevant indicators. Finally, some nonvegetarian self-selected diets consumed by a substantial fraction of the population showed good compatibility with the nutritional, environmental, affordability, and acceptability dimensions. Altogether, the reviewed studies revealed the scarcity of standardized nationally representative data for food prices and environmental indicators and suggest that diet sustainability might be increased without drastic dietary changes.

The Global Food‐Energy‐Water Nexus

“…As a result, there is much room for future research on identifying sustainable diets. Despite this variability, previous studies generally found that sustainable diets consist of less meat, particularly less beef and more vegetables, and tend to be similar to vegetarian, pescetarian, or Mediterranean diets (Hallström et al, 2015;Perignon et al, 2016Perignon et al, , 2017. These findings indicate that there are options to improve environmental and nutritional sustainability through diets (Tilman & Clark, 2014).…”

Are our diets getting healthier and more sustainable? Insights from the European Prospective Investigation into Cancer and Nutrition – Netherlands (EPIC-NL) cohort

“…The current Western diet is considered environmentally unsustainable and unhealthy due to the high quantities of animal-based foods consumed ( 9 , 10 ) . Shifts in dietary patterns towards less animal- and more plant-based foods can therefore potentially provide benefits for both the environment and health, as has been described by previous review studies ( 11 – 14 ) .…”

How Do Dietary Choices Influence the Energy-System Cost of Stabilizing the Climate?

“…Further, we have not included any positive effects from lower human consumption of red meat, although these may balance or outweigh the potential welfare loss mentioned above [52] nor have we included any added value of biological preservation (biodiversity) from the likely reduced demand for land resulting from the alternative diets.…”