Sodium density level of popular restaurant dishes in China
The analysis included a total 8131 menu foods from 192 restaurants in 6 provinces of China. The sample encompassed 3829 (47.1%) and 4302 (52.9%) foods from north and south area, 2285 (28.1%), 4162 (51.2%) and 1684 (20.7%) foods from large, medium and small restaurants, respectively. The dish type was mainly fried dish (83.9%), followed by cold dish (11.7%), soup (3.0%) and staples/snacks (1.4%).
In total, the restaurant dishes contained 487.3 (291.1, 781.9) mg sodium per 100g. The sodium level varied significantly by area, restaurant size, and dish type (Table 1). The highest sodium categories were south area (566.3mg per 100g), medium (497.5mg per 100g) and small (491.3mg per 100g) restaurants, soup (687.0mg per 100g), cold dish (528.4mg per 100g) and fried dish (480.9mg per 100g). Sodium mg per kcal showed similar trends, with the average sodium 3.4 (1.9, 6.4) mg per kcal. Categories with the highest sodium level per kcal were south area (3.6 mg), medium (3.5mg) and large (3.4mg) restaurant, cold dish (4.8mg), soup (4.3mg) and fried dish (3.3mg).
Table 1 Sodium level in Chinese restaurant dishes.
|
N
|
Sodium (mg) per 100g
|
|
Sodium (mg) per kcal
|
Median
|
P25
|
P75
|
|
P value
|
|
Median
|
P25
|
P75
|
P value
|
Area
|
|
|
|
|
|
|
|
|
|
|
|
North
|
3829
|
415.7
|
250.7
|
682.8
|
|
<0.0001
|
|
3.2
|
1.7
|
6.1
|
<0.0001
|
South
|
4302
|
566.3
|
337.9
|
858.4
|
|
|
3.6
|
2.0
|
6.5
|
Restaurant size
|
|
|
|
|
|
|
|
|
|
|
|
Large
|
2285
|
466.1
|
278.1
|
763.3
|
|
0.0286
|
|
3.4
|
1.8
|
6.7
|
0.0006
|
Medium
|
4162
|
497.5
|
297.7
|
798.0
|
|
|
3.5
|
1.9
|
6.5
|
Small
|
1684
|
491.3
|
302.1
|
767.1
|
|
|
3.1
|
1.8
|
5.7
|
Dish type
|
|
|
|
|
|
|
|
|
|
|
|
Cold dish
|
950
|
528.4
|
292.1
|
898.4
|
|
<0.0001
|
|
4.8
|
2.1
|
10.3
|
<0.0001
|
Fried dish
|
6819
|
480.9
|
291.1
|
762.3
|
|
|
3.3
|
1.9
|
6.0
|
Soup
|
246
|
687.0
|
409.6
|
1143.3
|
|
|
4.3
|
2.3
|
9.3
|
Staples/snacks
|
116
|
278.4
|
40.1
|
541.6
|
|
|
1.1
|
0.2
|
2.3
|
Total
|
8131
|
487.3
|
291.1
|
781.9
|
|
|
|
3.4
|
1.9
|
6.4
|
|
Sodium level per serving in restaurant dishes and compared to Chinese dietary reference intakes
Table 2 showed serving size, sodium (mg) per serving, %AI, and proportions of restaurant dishes exceeding the daily sodium AI (1500mg) and PI (2000mg) by categories. The average serving size was 575.6±318.0g, providing 3331.2±4156.9mg sodium per serving, 222.1% AI. In total, 74.9% of restaurant menu foods exceeded Chinese adults’ daily sodium AI, while 62.6% of foods exceeded the adults’ PI. Foods in categories of north area, large and medium restaurant, fried dish and soup had larger serving size and higher sodium (mg) per serving. In some instances, the higher sodium per serving was mainly due to higher sodium density, such as south area, cold dish, and small restaurant, while in other instances, it was due to larger serving size, such as north area, large restaurant, and staples/snacks, or due to the combination of both serving size and sodium density, such as medium restaurant, fried dish, and soup.
Table 2 Sodium levels of restaurant dishes in China compared to the dietary reference intakes (DRIs)
|
N
|
Mean serving size (g)
|
Sodium (mg) levels per serving
|
% of dishes exceeding the sodium DRIs levels ‡
|
Mean
|
SD
|
Mean
|
SD
|
%AI †
|
Median
|
P25
|
P75
|
AI: 1500 mg
|
PI: 2000 mg
|
Area
|
|
|
|
|
|
|
|
|
|
|
|
North
|
3829
|
620.0
|
340.2
|
3270.2
|
4849.9
|
218.0
|
2345.5
|
1409.3
|
3734.5
|
72.1
|
58.9
|
South
|
4302
|
536.1
|
291.2
|
3385.5
|
3423.7
|
225.7
|
2759.3
|
1596.3
|
4220.1
|
77.4
|
65.9
|
Restaurant size
|
|
|
|
|
|
|
|
|
|
|
|
Large
|
2285
|
611.4
|
377.9
|
3447.0
|
4774.4
|
229.8
|
2604.3
|
1527.5
|
4040.7
|
75.7
|
63.8
|
Medium
|
4162
|
576.4
|
291.3
|
3397.6
|
4219.8
|
226.5
|
2642.6
|
1579.3
|
4081.5
|
76.7
|
64.1
|
Small
|
1684
|
525.0
|
283.6
|
3010.1
|
2894.8
|
200.7
|
2283.6
|
1368.8
|
3901.9
|
69.5
|
57.4
|
Dish type
|
|
|
|
|
|
|
|
|
|
|
|
Cold dish
|
950
|
426.6
|
237.2
|
2975.5
|
4540.7
|
198.4
|
2018.3
|
1091.0
|
3251.5
|
62.3
|
50.5
|
Fried dish
|
6819
|
598.9
|
317.3
|
3356.1
|
3887.3
|
223.7
|
2614.1
|
1575.8
|
4082.2
|
76.9
|
64.4
|
Soup
|
246
|
574.0
|
357.3
|
4805.4
|
8190.7
|
320.4
|
3373.0
|
2112.2
|
4852.2
|
85.8
|
77.6
|
Staples/snacks
|
116
|
431.3
|
454.6
|
1653.1
|
2011.6
|
110.2
|
934.7
|
107.6
|
2354.3
|
36.2
|
27.6
|
Total
|
8131
|
575.6
|
318.0
|
3331.2
|
4156.9
|
222.1
|
2543.7
|
1496.9
|
4030.9
|
74.9
|
62.6
|
AI, adequate intake; PI, PI-NCD, proposed intake for preventing non-communicable chronic diseases.
† Mean sodium levels per serving, expressed as a percentage of the daily AI for adults (1500mg per day).
‡ Percentage of dishes in the groups that exceed the daily AI (1500 mg per day) or PI (2000 mg per day) per serving.
Sodium sources of restaurant dishes in China
For the total sample, cooking salt was the leading source of sodium in Chinese restaurant dishes, accounting for 45.8% (Figure 1). Monosodium glutamate was the second contributor (17.5%), followed by food ingredients (17.1%), soy sauce (9.4%), and other condiments/seasonings (10.2%). Beside sodium from food ingredients, the majority (82.9%) of sodium came from salted condiments/seasonings added in cooking procedure. However, cooking salt only contributed to less than half of sodium in restaurant dishes. On the other hand, monosodium glutamate, soy sauce and other condiments/seasonings (such as other sauces, compound condiments/seasonings) contributed to more than one third of total sodium in restaurant dishes.
Condiments/seasonings usage and association with sodium level in Chinese restaurant dishes
Figure 2 presented the prevalence of major salted condiments/seasonings by dish types in Chinese restaurants. In total, 76.8% of foods contained cooking salt, while 71.1% and 41.7% of foods contained monosodium glutamate and soy sauce, respectively. However, other condiments/seasonings beside the above three categories of salted condiments/seasonings, were found in the 94.2% of restaurant dishes, and were most prevalent in all food types. Cooking salt was another major salted condiment for all type restaurant dishes, especially for soup (91.9%) and fried dish (77.8%). Monosodium glutamate was more often used in soup (80.9%) and fried dish (73.0%), followed by cold dish (60.0%). Soy sauce was a popular salted condiment/seasonings in China, being found in 43.8% of fried dish and 33.0% of cold dish. In staples/snack, prevalence of condiments/seasonings was below 50%, except for that of other condiments/seasonings.
Among all the samples included, nearly one half of restaurant dishes (45.1%) contained 3 categories of salted condiments/seasonings, followed by those contained 2 categories (24.2%) and 4 categories (23.3%) condiments/seasonings (Table 3). Only 7.4% of foods was added 1 category salted condiments/seasonings in cooking. Foods in south area, small restaurants and fried dish were more likely to contain all 4 categories of salted condiments/seasonings. Generally, foods that contained more categories of condiments/seasonings were significantly likely to have higher sodium level than those contained less categories of salted condiments/seasonings. This trend was seen in all subgroups, and the difference was significant (P<0.0001). The median value of sodium (mg) per 100g in foods with 4 categories of condiments/seasonings (644.4mg per 100g) was 4.8 times that of foods with 1 category of condiments/seasonings (134.8mg per 100g), 1.7 times of those with 2 categories (380.7mg per 100g), 1.3 times of those with 3 categories (506.4 mg per 100g).
Table 3. Sodium level by category amounts of salted condiment/seasonings in Chinese restaurant dishes (N=8131).
|
P value*
|
Category amounts of salted condiment/seasonings †
|
1 category
|
2 categories
|
3 categories
|
4 categories
|
%
|
sodium (mg) per 100g
|
%
|
sodium (mg) per 100g
|
%
|
sodium (mg) per 100g
|
%
|
sodium (mg) per 100g
|
Median
|
P25
|
P75
|
Median
|
P25
|
P75
|
Median
|
P25
|
P75
|
Median
|
P25
|
P75
|
Area
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
North
|
<0.0001
|
8.8
|
113.2
|
29.9
|
396.4
|
22.0
|
342.1
|
191.9
|
539.2
|
49.1
|
445.5
|
290.8
|
713.2
|
20.1
|
500.6
|
346.6
|
783.8
|
South
|
6.2
|
146.2
|
43.9
|
488.8
|
26.1
|
408.0
|
259.6
|
705.6
|
41.6
|
578.9
|
370.1
|
911.0
|
26.1
|
704.3
|
533.2
|
998.9
|
Restaurant size
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Large
|
<0.0001
|
8.9
|
138.2
|
38.0
|
432.0
|
21.9
|
344.0
|
214.6
|
538.1
|
45.4
|
481.2
|
303.4
|
797.1
|
23.8
|
648.7
|
429.7
|
917.5
|
Medium
|
7.3
|
121.7
|
30.6
|
455.9
|
24.9
|
399.2
|
235.3
|
646.2
|
45.2
|
527.6
|
335.5
|
827.9
|
22.7
|
644.4
|
432.7
|
934.0
|
Small
|
5.9
|
138.7
|
35.6
|
405.8
|
25.7
|
386.2
|
234.5
|
666.3
|
44.5
|
486.7
|
317.0
|
763.0
|
24.0
|
640.3
|
444.8
|
901.4
|
Dish type
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Cold dish
|
<0.0001
|
15.1
|
139.4
|
36.0
|
479.9
|
25.1
|
470.2
|
272.9
|
709.2
|
47.3
|
615.4
|
372.4
|
970.3
|
12.6
|
729.6
|
414.6
|
1191.6
|
Fried dish
|
5.8
|
145.1
|
48.6
|
456.6
|
24.3
|
367.4
|
221.8
|
598.5
|
44.9
|
486.7
|
313.3
|
764.4
|
25.1
|
637.8
|
432.8
|
898.5
|
Soup
|
5.3
|
73.7
|
21.4
|
309.7
|
22.0
|
667.0
|
401.1
|
1141.9
|
52.4
|
696.4
|
388.2
|
1239.0
|
20.3
|
791.3
|
572.8
|
1118.6
|
Staples/snacks
|
48.3
|
39.5
|
5.3
|
178.1
|
14.7
|
393.0
|
276.7
|
554.7
|
24.1
|
507.0
|
360.8
|
777.6
|
12.9
|
461.1
|
301.8
|
777.4
|
Total
|
<0.0001
|
7.4
|
134.8
|
35.9
|
441.6
|
24.2
|
380.7
|
228.3
|
630.7
|
45.1
|
506.4
|
321.6
|
810.0
|
23.3
|
644.4
|
436.6
|
919.7
|
† Category of salted condiments/seasonings includes: cooking salt, monosodium glutamate, soy sauce, and other condiments/seasoning.
* Non-parametric Wilcoxon signed-rank tests of sodium level among different category amounts groups of salted condiment/seasonings.