National dietary guidelines provide a set of principles to guide decisions about healthy diet and lifestyle. They should be informed by scientific evidence and country-specific public health and nutrition priorities, as well as sociocultural and contextual factors. Dietary guidelines commonly propose a set of recommendations related to the consumption of individual foods and/or food groups in sufficient quantities to meet nutrient intake requirements based on life stage and sex, for both health promotion and chronic disease prevention. More recently developed national dietary guidelines have included holistic contexts for eating, by addressing food combinations (meals), food safety considerations, lifestyle factors, sustainability, and other aspects of eating.

The scope of this Special Issue is to publish original research and systematic reviews that report findings on the assessment of healthy eating based on the development, implementation, evaluation, and impact of national dietary guidelines. The Special Issue brought together a selection of original research manuscripts and reviews to showcase the latest evidence on the use of dietary guidelines as a basis for the development of tools and methodologies to influence population eating patterns and promote healthy eating and diet quality at different life stages, as well as associations with health and disease.