Awareness, understanding and use of sodium information labelled on pre-packaged food in Beijing:a cross-sectional study

BACKGROUND: Nutrition labelling has been mandatory for pre-packaged foods since 2013 in China, and sodium is one of the nutrients required for display on the nutritional information panel (NIP). This study aimed to estimate the awareness, understanding of, and use of sodium labelling information among the population in China. METHODS: A cross-sectional survey was carried out in urban Beijing in 2016 on pre-packaged foods. The researchers randomly selected 380 residents from four convenient but disconnected communities and 370 shoppers from four supermarkets owned by different companies and conducted face-to-face interviews. Questions on nutritional knowledge, health attitude, understanding and use of nutritional labels as well as other related factors were assessed. RESULTS: All of the 380 community residents and 308 of the 370 supermarket shoppers successfully completed the survey. Of those 688 respondents, 91.3% understood that excessive salt intake was harmful, 19.5% were aware that sodium content is listed on the NIP, 5.5% understood the meaning of NRV% (Percentage of Nutrient Reference Values), 47.7% did not know the relationship between sodium and salt, and 12.6% reported they frequently read the label when shopping. Factors for why people were more likely to choose a product because of its low level of salt shown on the label include income level and their level of awareness of the link between salt and diet. CONCLUSIONS: Although the participants had a good understanding of the harmful effects of salt, the awareness, understanding and use of sodium labels was very low in Beijing, and even worse nationwide. Efforts should be taken to educate the public to understand and use the NIP better and design clearer ways of displaying such information, such as front-of pack (FoP) labelling or health-related smartphone applications to improve health and help people make better food choices. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12889-018-5396-7) contains supplementary material, which is available to authorized users.