Sodium Content in Pre-Packaged Foods in China: A Food Label Analysis

Sodium intake from pre-packaged foods is increasing in China and is well above the WHO recommendation of 5 g per day. The purpose of this study is to analyze the sodium content of pre-packaged foods collected by the National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention (NINH, China CDC) in 20 provinces of China from 2017 to 2022. The proportion of pre-packaged foods that meet or exceed the low-sodium, medium-sodium, and high-sodium classifications were analyzed. The proportion of pre-packaged foods that meet and do not meet the WHO global sodium benchmarks and the difference in sodium content between these foods was also calculated. High-sodium foods include sauces, dips, and dressings (3896 mg/100 g), convenience foods (1578 mg/100 g), processed fish products (1470 mg/100 g), processed meat products (1323 mg/100 g), processed poultry products (1240 mg/100 g), snack foods (750 mg/100 g), processed egg products (741 mg/100 g), and fine dried noodles (602 mg/100 g). A large number of pre-packaged foods currently collected in China have a sodium content above sodium benchmarks. This study provided data to support the assessment of sodium intake from pre-packaged foods in the Chinese population and the implementation of comprehensive salt reduction strategies.


Introduction
High sodium intake is an important risk factor for high blood pressure [1,2], cardiovascular disease [3], stroke [4], stomach cancer [5], and premature mortality [6].High sodium intake has led to 1.9 million deaths globally [7].The World Health Organization (WHO) recommends a sodium intake for adults of less than 2 g/day (i.e., 5 g/day of salt) [8].However, the current Chinese adult's average salt intake is estimated to be 9.3 g/day per person [9], which is 86% higher than the WHO's recommendation [8].The consumption of pre-packaged foods in China continues to increase [10,11].
WHO makes sodium reduction a global priority and "best buy" [12,13].In 96 national salt reduction initiatives, 89 countries combined two or more implementation strategies, including interventions in settings, food reformulation, consumer education, front-of-pack labelling (FOPL), and salt taxation [14].The UK [15], the USA [16], and Canada [17] set voluntary salt reduction targets for pre-packaged foods; the South African government set maximum sodium content in various categories of processed foods [18]; Chile, Peru, and Uruguay adopted a front-of-pack warning label (FOPWL) [19,20]; and Fiji and Mexico adopted taxes on foods high in salt [14].
Nutrients 2023, 15, 4862 3 of 13 group standards, and industry standards for food published by the Chinese government (Supplementary Table S1), with full consideration of the characteristics of pre-packaged foods, their processing technologies, formulation, and Chinese dietary habits, pre-packaged foods have been classified step by step.The specific number and distribution of various pre-packaged foods are shown in Table 1 and Figure 1.

Data Classification
According to the Standard on Nutrition Labelling of Pre-packaged Foods (GB 28050-2011) [21], the Standards for Uses of Food Additive (GB 2760-2014) [23], Regulation of Food Composition Data Expression (WS/T 464-2015) [24], as well as various national standards, group standards, and industry standards for food published by the Chinese government (Supplementary Table S1), with full consideration of the characteristics of pre-packaged foods, their processing technologies, formulation, and Chinese dietary habits, pre-packaged foods have been classified step by step.The specific number and distribution of various pre-packaged foods are shown in Table 1 and Figure 1.

Data Inclusion and Exclusion Criteria
Pre-packaged foods with complete NIPs and ingredients were included.The Standard on Nutrition Labelling of Pre-packaged Foods (GB 28050-2011) specifies mandatory rules for nutrition labelling by manufacturers to provide quantitative information on energy, protein, fat, carbohydrate, and sodium content of foods and their contributions to the Nutrient Reference Value (NRV).Foods with incorrect or incomplete nutrition information and foods that were missing ingredient information or could not be classified into target categories were excluded from the analysis.

Data Analysis
Data for sodium (mg/100 g) for each subcategory of pre-packaged foods are presented as median, proportion, range, and IQR means interquartile range.
According to the Standard on Nutrition Labelling of Pre-packaged Foods (GB 28050-2011), foods with a sodium content not higher than 120 mg/100 g were classified into low-sodium foods [21].According to the recommendation of Dietary Guidelines for Chinese (2022), sodium content that exceeds 30% of NRV is high; thus, foods with sodium content higher than 600 mg/100 g were classified as high-sodium foods [9].The foods with sodium content between 120 and 600 mg/100 g were classified as medium-sodium foods.These are shown as green, yellow, and red according to a horizontal bar chart to indicate the percentage of low-sodium, medium-sodium, and high-sodium foods.
The proportion of pre-packaged foods meeting and not meeting WHO global sodium benchmarks and the difference in sodium content of the corresponding products was calculated and presented as median and IQR.The analyses were conducted using IBM SPSS V.26.0.

The Sodium Content for Chinese Pre-Packaged Foods
From a total of 7825 pre-packaged foods collected from China, 38 were excluded due to incorrect or incomplete nutrition information, 44 were excluded due to missing ingredient information, and 83 were excluded due to not being classified into target categories (Figure 2).Finally, this study included a total of 7660 products.Chinese pre-packaged foods were classified into 20 categories and 38 subcategories (Table 1).
are shown as green, yellow, and red according to a horizontal bar chart to indicate the percentage of low-sodium, medium-sodium, and high-sodium foods.
The proportion of pre-packaged foods meeting and not meeting WHO global sodium benchmarks and the difference in sodium content of the corresponding products was calculated and presented as median and IQR.The analyses were conducted using IBM SPSS V.26.0.
It can be seen from Table 1 that sodium content varied significantly within certain food subcategories: cake and pastry products (47 mg/100 g in moon cakes to 238 mg/100 g in western-style pastries), biscuits (107 mg/100 g in egg roll to 480 mg/100 g in soda biscuits), snack foods (59 mg/100 g in dried fruit to 2590 mg/100 g in extruded flavouring noodles), processed meat products (458 mg/100 g in prepared meat products to 1987 mg/100 g in cured meat products), processed poultry products (693 mg/100 g in prepared poultry products to 1536 mg/100 g in dried poultry products), processed fish products (701 mg/100 g in other fish products to 1561 mg/100 g in cooked fish and seafood products), and sauces, dips, and dressings (2000 mg/100 g in pickled vegetables to 6600 mg/100 g in soy sauces).Among the subcategories of bread and bakery products, the difference in sodium content was relatively small.The highest proportion of high-sodium foods included products within the categories of sauces, dips, and dressings (96.6%), processed meat products (95.6%), processed poultry products (94.8%), processed fish products (91.3%), convenience foods (86.7%), processed egg products (77.3%), snack foods (60.0%), and fine dried noodles (50.3%).Bread and bakery products, cheese, biscuits, cake and pastry products, and frozen rice and flour products had a relatively high proportion of medium-sodium products.Chocolate, sugar confectionery and jelly, beverages, edible ices, yogurt, sour milk, and similar foods, and edible oil had relatively low sodium content, ranging from 0 mg/100 g to 72 mg/100 g (Figure 3).
It can be seen from Table 1 that sodium content varied significantly within certain food subcategories: cake and pastry products (47 mg/100 g in moon cakes to 238 mg/100 g in western-style pastries), biscuits (107 mg/100 g in egg roll to 480 mg/100 g in soda biscuits), snack foods (59 mg/100 g in dried fruit to 2590 mg/100 g in extruded flavouring noodles), processed meat products (458 mg/100 g in prepared meat products to 1987 mg/100 g in cured meat products), processed poultry products (693 mg/100 g in prepared poultry products to 1536 mg/100 g in dried poultry products), processed fish products (701 mg/100 g in other fish products to 1561 mg/100 g in cooked fish and seafood products), and sauces, dips, and dressings (2000 mg/100 g in pickled vegetables to 6600 mg/100 g in soy sauces).Among the subcategories of bread and bakery products, the difference in sodium content was relatively small.
Bread and bakery products, cheese, biscuits, cake and pastry products, and frozen rice and flour products had a relatively high proportion of medium-sodium products.Chocolate, sugar confectionery and jelly, beverages, edible ices, yogurt, sour milk, and similar foods, and edible oil had relatively low sodium content, ranging from 0 mg/100 g to 72 mg/100 g (Figure 3).

The Median Sodium Content of Chinese Pre-Packaged Foods Meeting and Not Meeting WHO Global Sodium Benchmarks
The sodium content of Chinese pre-packaged foods in each food subcategory was compared with the related sodium benchmarks (Figure 4).A large proportion of products in the subcategories of frozen rice and flour products, convenience foods, processed meat products, processed poultry products, processed fish products, and sauces, dips, and dressings did not meet the related sodium benchmarks, ranging from 55.4% to 100.0%.The proportion of foods in subcategories such as biscuits, bread and bakery products, cheese, cereals, and congee meeting sodium benchmarks was relatively high.Among these categories, the proportions of soda biscuits, sandwich biscuits, and cereals meeting the sodium benchmarks were 95.0%, 93.0%, and 91.5%, respectively.
Among foods that met sodium benchmarks and those that did not, the category with the greatest difference in median sodium content is congee (34 mg/100 g in meeting to 1243 mg/100 g in not meeting), and the difference in sodium content of products that did not meet the requirements is about 36.6 times that of products that met the requirements, followed by paste and like products (20.5 times) and frozen rice and flour products (8.8 times).The difference in median sodium content between soda biscuits that met sodium benchmarks and those that did not is minimal.The difference in median sodium content between other subcategories ranges from 1.5 to 8.4 times.(Table 2).

Discussion
High sodium intake is the major dietary risk factor for deaths and DALYs in China [26][27][28]; pre-packaged foods are gradually becoming an important source of dietary sodium for the Chinese.This study analyzed the sodium content of pre-packaged foods collected by NINH, China CDC in 20 provinces of China from 2017 to 2022.We also analyzed the proportion of foods that meet or exceed the low-sodium, medium-sodium, and high-sodium.Compared with the published articles, this study also calculated the proportion of foods that meet and do not meet the WHO global sodium benchmarks, as well as the difference in sodium content of the corresponding foods.This study provided data to support the implementation of comprehensive salt reduction strategies, such as setting salt reduction targets for different categories of pre-packaged foods, improving food reformulation, and promoting the development of FOPL.
In this study, we observed that sauces, dips, and dressings had the highest median sodium content (3896 mg/100 g), and the distribution of sodium content in this category is very wide, ranging from a minimum sodium content of 0 mg/100 g to a maximum sodium content of 23,696 mg/100 g.The sodium content of sauces, dips, and dressings in this study is much lower than in 14 Latin American and Caribbean countries (7778 mg/100 g) [29] but much higher than in countries such as the UK (440 mg/100 g) [30], the USA (600 mg/100 g) [30], and Fiji (1422 mg/100 g) [31].Sauces, dips, and dressings are special products that are not only an ingredient in pre-packaged foods but also an important source of sodium for the Chinese [32].In the sauces, dips, and dressings category, 96.6% are high-sodium foods, and soy sauces, pickled vegetables, fermented bean curd, and paste and like products exceeded the sodium benchmark by 88.3%, 99.6%, 100.0%, 91.2%, respectively.A study that evaluated the sodium content of sauces in the UK over the past 10 years found that 70.0% of products met the UK maximum salt targets [33].The wide range of sodium content distribution in sauces, dips, and dressings, as well as the fact that a high proportion of UK products have achieved the goal of salt reduction targets, means that there is still a lot of room for China to reduce sodium content in this category.
Pre-packaged foods commonly consumed by Chinese consumers include convenience foods, processed meat and poultry products, and snack foods, among others [10,34,35].We found that most of these categories belong to high-sodium foods, and more than 70% of processed meat products, processed poultry products, processed fish products, and convenience foods did not meet sodium benchmarks.Therefore, in response, stricter measures to reduce sodium content should be implemented in these categories.However, researchers reported that the rate of achievement of salt reduction targets in categories such as processed meat and fish products and instant noodles was very low.In China, only 7.1% of processed meat and fish products met the UK's sodium reduction targets [36], while 26% of instant noodles met the Pacific Salt Reduction Target (1600 mg/100 g) and 24% met the South Africa 2016 Target (1500 mg/100 g) [37].Reducing the sodium content of pre-packaged foods that are high in sodium, high in consumption, or both can help reduce nearly 90% of the sodium intake from pre-packaged foods [38].Therefore, strong sodium reduction policies should be implemented to regulate the sodium content of these categories, and technical issues should not become an obstacle to the high sodium content of these categories.There is evidence to support the feasibility of new approaches to reducing sodium content in pre-packaged foods, such as salt removal, salt replacement, flavour modification, functional modification, or physical modification [39].
In 2021, the WHO established global sodium benchmarks for 18 categories and 97 subcategories that were based on the lowest value for each subcategory from existing national and regional targets [25].These sodium benchmarks ensure that products from all countries contain the same amount of sodium and provide a reference point for countries to set targets for salt in foods.If all pre-packaged foods met WHO global sodium benchmarks, the average sodium intake of the Chinese population would be reduced by 13.9% [38].However, achieving this goal means that approximately 46.9% of Chinese packaged food needs to be reformulated [38]; this result is similar to the study by Martini et al. [40], in which they found the sodium content of most of the items of cereal-based products currently sold on the Italian market is much higher than sodium benchmarks.These results indicate that further efforts are needed globally to reduce the sodium content in pre-packaged foods.It is noteworthy that China has implemented voluntary salt reduction targets for pre-packaged foods, labelled "Healthy Choice" FOPL on lower-sodium products, and held an annual "China Salt Reduction Week" to help Chinese reduce salt intake.
Comprehensive salt reduction strategies in countries such as Finland and the UK have shown significant results.The multicomponent salt-reduction initiative led by the Finnish Government [41,42] resulted in a decrease in the average daily salt intake in Finland by 36% [43].The comprehensive salt-reduction strategy led by the UK Government has reduced the sodium content of a wide range of packaged food categories by 20% to 50%, and overall population salt intake has decreased by 15% [15].Comprehensive strategies could generally achieve the biggest reductions in salt consumption across an entire population; food reformulation may be one of the best strategies for reducing sodium intake [44,45].The current Chinese adult's average salt intake is 86% higher than the WHO's recommendation [8].This means that China needs to take stronger measures to reduce sodium intake and monitor and evaluate the effectiveness of these measures.
The latest report from the WHO stated that by accelerating the implementation of salt reduction policies, it is possible to meet the 2013 target of a 20% reduction in sodium intake and potentially avoid over 7 million deaths by 2030 [7].China is committed to implementing and updating salt reduction measures, including developing FOPWL, revising salt reduction targets for pre-packaged foods, and promoting the use of low-sodium salt in China.Currently, NINH, China CDC has established a working group on guidelines for salt reduction in collaboration with the Chinese Nutrition Society and has revised Guidelines for Salt Reduction in the Chinese Food Industry.This Guideline provides a detailed classification of pre-packaged foods based on food characteristics, processing techniques, recipes, and Chinese eating habits, and plans to set the latest average salt content target and maximum salt content target for sodium reduction in pre-packaged foods.This Guideline also provides food manufacturers with scientific and practical guidance on salt reduction technologies, sets nutritional food processing standards and work targets, creates a progressive nutritional culture and policy environment, and guarantees support for consumer health.It is important to note that the National Nutrition Plan (2017-2030) aims to reduce daily sodium intake by 20%, and the WHO aims to reduce sodium intake by 30% by 2030.
The strength of this study is the fact that it included a large number of pre-packaged foods in the Chinese food and beverage supply.Compared with the published articles, this study also calculated the proportion of foods that met and did not meet the WHO global sodium benchmarks, as well as the difference in sodium content of the corresponding foods.An important limitation of the current research was that it was based on the nutritional information provided on the nutrition label and did not include actual measurements of sodium in pre-packaged foods.

Conclusions
This study analyzed the sodium content of 7660 products in 20 categories and 38 subcategories.The highest median sodium levels per 100 g were among sauces, dips, and dressings, convenience foods, processed fish products, processed meat products, processed poultry products, snack foods, processed egg products, and fine dried noodles, and these were classified as high-sodium foods.A large number of pre-packaged foods currently collected in China have a sodium content above the global sodium benchmarks.This study provided data to support the implementation of comprehensive salt reduction strategies, such as setting salt reduction targets for different categories of pre-packaged foods, improving food reformulation, and promoting the development of FOPL to help reduce sodium intake among the Chinese population and further reduce diet-related NCDs.

3. 2 .
Proportion of Chinese Pre-Packaged Foods Meeting Low-Sodium, Medium-Sodium, and High-Sodium Content

Figure 3 .
Figure 3. Proportion of Chinese pre-packaged foods meeting low-sodium, medium-sodium, and high-sodium content by categories.

Figure 3 .
Figure 3. Proportion of Chinese pre-packaged foods meeting low-sodium, medium-sodium, and high-sodium content by categories.

Table 1 .
The sodium content of Chinese pre-packaged foods by categories.

and bakery products Fine dried noodles Processed meat products Processed poultry products Processed fish products Processed egg products Sauces, dips, and dressings Figure
1. Distribution of Chinese pre-packaged foods.

Table 1 .
The sodium content of Chinese pre-packaged foods by categories.

Table 2 .
The sodium content of Chinese pre-packaged foods meeting and not meeting WHO global sodium benchmarks, median (IQR).