Regional Trends in Dietary Intake in Japan: the 2003~2017 National Health and Nutrition Survey

Abstract

Objective: There are regional health disparities in Japan regarding the physical condition and lifestyle as demonstrated in the gaps among prefectures. However, no regional annual trends have been reported. This study investigated the regional trends in dietary intake among Japanese adults.

Methods: Overall, 140,817 Japanese participants (64,773 men and 76,044 women) aged ≥20 years, registered in the 2003~2017 National Health and Nutrition Survey were included. The dietary survey was conducted with a semi-weighted household-based dietary record on a single day. The 47 prefectures were regrouped into 12 regions. Age-adjusted mean intakes of energy, carbohydrate, fat, protein, salt, vegetables, and fruits by region were estimated using a regression model, according to the survey years. Trend analyses from 2003 to 2017 were performed using the Joinpoint Regression Program.

Results: Significant decreases in carbohydrate and salt intake were noted in all regions, whereas fat intake showed a significant change in trend with annual increases. Protein intake decreased in approximately half and fruit intake decreased in two thirds of the regions. No changes in trend in energy and vegetable intake were observed in most regions, although a declining annual trend was observed in some regions.

Conclusions: In Japan, annual trend in intakes of energy, protein, vegetables, and fruits differed among regions from 2003 to 2017. These results may be attributed to the differences in health and nutrition policies between local governments. Regional trends in dietary intake among Japanese need to be monitored continuously to develop health and nutrition policies for local governments.