Planetary Health Diet Adherence in Korean Adults: Association with the Korean Healthy Eating Index

The Planetary Health Diet (PHD) was developed to address global health and environmental challenges by promoting sustainable and nutritionally adequate eating patterns. This study evaluated adherence to the PHD among Korean adults and examined its association with the Korean Healthy Eating Index (KHEI), with the aim of informing the development of a Korea-specific PHD adherence index.

Using data from the 2013-2023 Korea National Health and Nutrition Examination Survey (KNHANES), dietary intake of adults aged ≥19 years was analyzed. Adherence was assessed by comparing food group consumption with PHD reference ranges, and KHEI scores were calculated to examine their association with PHD compliance and nutrient intake. Analyses were also stratified by sex to examine differences in intake patterns.

Men generally consumed larger quantities and had higher frequencies of intake across most food groups, whereas women consumed more fruits and dairy products. However, both sexes showed insufficient consumption of whole grains, legumes, and nuts, and red meat intake far exceeded the suggested limits. Participants with higher KHEI scores demonstrated greater intake of plant-based proteins and lower intake of red meat and saturated fats. Nutrient profiles also improved with higher KHEI scores.

These findings suggest that better diet quality, as indicated by higher KHEI scores, is aligned with more sustainable eating behaviors and that that the KHEI may serve as a practical proxy for assessing adherence to the PHD. However, persistent gaps in whole grain, legume, and nut intake, together with excessive red meat consumption, highlight the need for culturally adapted guidelines and strategies to promote sustainable dietary shifts in Korea.