The aim of this study is to conduct a comparative analysis across nations to: (1) identify the determinants influencing knowledge and attitudes related to sodium (Na) intake and (2) to analyse the association between knowledge and attitudes related to Na intake.

We utilised a secondary data from a cross-sectional study that was conducted across seven nations. Structural equation modelling (SEM) was utilised to assess the impact of socio-economic and health-related predictors on knowledge and attitudes pertaining to Na intake and further to investigate the relationship between knowledge and attitude.

Indonesia, Brazil, Thailand, Japan, France, the UK and the USA.

7090 participants aged 15 years and above were included in the study.

SEM analysis showed a strong association between knowledge about Na intake and related attitude across all countries, particularly in the UK (2·65, 95 % CI 1·48–3·82), France (2·62, 1·45–3·79) and the USA (1·97, 1·21–2·73). In Brazil, Japan and France, individuals or family members having certain health conditions such as raised blood pressure, heart diseases, strokes or other diseases exhibited a positive attitude towards reducing Na intake. Conversely, socio-economic factors like education and income demonstrated the complexity of influences on knowledge and attitudes about Na intake.

The study underscores the need for tailored public health interventions to reduce excessive Na consumption, considering the diverse cultural, social and economic factors. It highlights the complex determinants of knowledge and attitudes towards Na intake, calling for further research in varied populations.

To estimate the consumption of ultra-processed foods and determine its association with dietary quality among middle-aged Japanese adults.

Cross-sectional study using data from the Saitama Prefecture Health and Nutrition Survey 2011. Dietary intake was assessed using one- or two-day dietary records. Sociodemographic and lifestyle factors were obtained via self-administered questionnaire. Food items were classified according to the NOVA system into four groups: unprocessed or minimally processed foods; processed culinary ingredients; processed foods; and ultra-processed foods. The dietary share of each NOVA food group and their subgroups was calculated in relation to total energy intake, and the average dietary content of key nutrients was determined across tertiles of the dietary energy share of ultra-processed foods (low, middle and high intake).

Saitama Prefecture in Japan.

Community-dwelling adults aged 30–59 years (256 men, 361 women).

Consumption of unprocessed or minimally processed foods, processed culinary ingredients, processed foods and ultra-processed foods contributed 44·9 (se 0·8) %, 5·5 (se 0·2) %, 11·3 (se 0·4) % and 38·2 (se 0·9) % of total daily energy intake, respectively. A positive and statistically significant linear trend was found between the dietary share of ultra-processed foods (tertiles) and the dietary content of total and saturated fat, while an inverse relationship was observed for protein, vitamin K, vitamin B6, dietary fibre, magnesium, phosphorus and iron.

Our findings show that higher consumption of ultra-processed foods was associated with decreased dietary quality among Japanese adults.