Dietary intake and sources of sodium and potassium, and salt-related knowledge, attitudes, and behaviours among rural adults in China: a cross-sectional study

We assessed dietary intake and sources of sodium and potassium, and salt-related knowledge, attitudes, and behaviours (KAB) among rural adults in four Chinese provinces. This cross-sectional study was conducted in four provinces in China, with two counties per province and eight villages per county purposively selected. Participants (18–69 years) were enrolled using stratified random sampling by sex and age in each village. Sodium and potassium intake were estimated using eligible 24-h urine samples, with a 24-h dietary recall collected from a 25% subsample to assess dietary sources. Salt-related KAB was assessed using an interviewer-administered questionnaire. Data were summarized using sampling weights as means (SE) for continuous variables and weighted proportions for categorical variables. A total of 2,669 participants were recruited between August 2021 and May 2023. Mean sodium and potassium intake was 5.8 g/day (SE 0.1) and 2.39 g/day (SE 0.04), respectively, equivalent to 14.7 g/day of salt (SE 0.2). Overall, 77.7% of participants were aware of the health risks of excessive salt or salty sauce intake, 67.3% recognized the importance of reducing salt in cooking, and 50.1% reported trying to reduce salt intake. We find that 72.1% of sodium intake came from salt added during home cooking, while cereals and tubers were the main sources of potassium. Rural Chinese adults consume excessive sodium and insufficient potassium relative to World Health Organization recommendations, with generally poor attitudes and adoption of salt-reduction behaviours. These findings highlight the need for interventions that strengthen salt-reduction education, provide practical tools, and improve supportive food environments.