Trends in dietary salt sources in Japanese adults: data from the 2007–2019 National Health and Nutrition Survey

Abstract

Identifying trends in dietary salt sources is essential for effectively reducing salt/sodium intake. This study aimed to examine the trends in dietary salt sources among Japanese adults using the 2007–2019 National Health and Nutrition Survey data collected from 95,581 adults aged ≥20 years. Dietary intake was estimated using the 1-day household-based dietary record. Foods reported as potential sources of salt intake in Japan and other countries were categorised into 21 groups. Salt intake for each food group was adjusted using the density method based on the energy intake. Trends in dietary salt intake based on food sources by sex and age groups (20–39 years, 40–59 years, and ≥60 years) were analysed using the Joinpoint Regression Program. Salt intake for each age group in both men and women decreased from 2007 (5.3g/4184kJ – 6.4g/4184kJ) to 2019 (4.9g/4184kJ – 5.6g/4184kJ). The major dietary source of salt continued to be seasonings such as soy sauce and soybean paste (approximately 70%). Salt intake from seasonings decreased over time in adults aged ≥40 years but did not change in those aged 20-39 years. Additionally, a decreasing salt intake from unprocessed fish and shellfish and an increasing salt intake from unprocessed meat were observed across all age categories for both sexes. This study demonstrated that a strategy targeting different age groups may be needed to reduce salt consumption from seasonings among the Japanese population. Further studies on salt content in seasonings and continued monitoring of trends in dietary salt sources are required.

Association between home meal preparers and salt intake in haemodialysis patients: a cross-sectional study

“…Regarding the association between age and salt intake, a previous study reported that ageing leads to a total reduction in dietary intake, and the consequence of such a reduction is a decrease in salt intake. 22 Although that study was conducted with mostly middle-aged and older adults, it may be fair to assume that a similar trend would be found among the haemodialysis patients in our study. Regarding salt reduction compliance, a previous study 23 reported that such compliance was associated with the perceived benefit of salt reduction for the future.…”

A scoping review of dietary assessment questionnaires potentially suitable for assessing habitual dietary intake in the National Health and Nutrition Survey, Japan

“…In the future, it will be necessary to verify whether the 11 questionnaires identified in the present study can be used in the NHNS participants or sub-sample of them (not only in terms of validity and feasibility but also in terms of participation rates, and consistency with previous NHNS results). Additionally, although 11 questionnaires were extracted in the present study, the dietary patterns, energy, macro nutrient and salt intake among Japanese have changed over time ( 82 – 84 ) . It will be necessary to periodically examine the feasibility of using the questionnaires to monitor changes in the dietary intake of the Japanese population through the NHNS.…”

Relationship between Household Shared Meal Frequency and Dietary Intake among Men and Women Aged ≥20 Years: Cross-Sectional Analyses Based on 2018 and 2019 National Health and Nutrition Surveys in Japan

“…Furthermore, differences in sodium intake to the shared meal frequency were observed between men and women. In men, although condiments (the largest food source for sodium intake) [ 41 ] increased with a shared meal frequency, sodium intake did not. One interpretation would be that the same condiment was consumed across the shared meal frequencies, and sodium intake from other food sources decreased in men; this is possible given that the intake of cereals (including bread and instant noodles) and confectioneries (including savory snacks) was reduced across the shared meal frequencies.…”