Measuring Adherence to Sustainable Healthy Diets: A Scoping Review of Dietary Metrics

Abstract

Comprehensive metrics that provide a measure of dietary patterns at global and national levels are needed to inform and assess the effectiveness of policy actions that promote sustainable healthy diets. In 2019, the Food and Agriculture Organization of the United Nations and the World Health Organization reported 16 guiding principles of sustainable healthy diets, but it is still unknown how these principles are considered in dietary metrics. This scoping review aimed to explore how principles of sustainable healthy diets are considered in dietary metrics used worldwide. Forty-eight food-based, investigator-defined dietary pattern metrics assessing diet quality in free-living, healthy populations at the individual or household level were assessed against the 16 guiding principles of sustainable healthy diets, which was used as a theoretical framework. A strong adherence of the metrics to health-related guiding principles was found. Metrics had a weak adherence to principles related to environmental and sociocultural aspects of diets, except for the principle related to diets being culturally appropriate. No existing dietary metric captures all principles of sustainable healthy diets. Notably, the significance food processing, environmental, and sociocultural aspects of diets are generally understated. This likely reflects the lack of focus on these aspects in current dietary guidelines, which highlights the importance of including these emerging topics in future dietary recommendations. The absence of quantitative metrics that comprehensively measure sustainable healthy diets limits the body of evidence that would otherwise inform national and international guideline developments. Our findings can help grow the quantity and quality of the body of evidence available to inform policy activities to realize 2030 Sustainable Development Goals of multiple United Nations.