Objective To understand the current salt reduction environment and the sodium content of popular dishes in restaurants and canteens in Beijing, thereby providing a scientific basis for the salt reduction intervention in the future.

Methods A questionnaire survey was conducted among 3 083 random diners from 47 restaurants of different scales and 20 canteens in 12 districts of Beijing from May to August 2022 to understand the salt reduction environment and salt reduction services. Two hundred popular dish samples were collected, and inductively coupled plasma-mass spectrometry (ICP-MS) was employed to measure the sodium content in the dish samples. The chi-square test was performed for inter-group comparisons of the salt reduction environment, while the Wilcoxon rank sum test and the Kruskal-Wallis H rank sum test were conducted for inter-group comparisons of sodium content in dishes.

Results The proportions of restaurants and canteens with signs related to low salt diet were 53.19% (25/47) and 65.00% (13/20), respectively. The proportions of restaurants and canteens with reading materials for salt reduction were 51.06% (24/47) and 65.00% (13/20), respectively. The proportions of restaurants and canteens offering low-salt dishes were 55.32% (26/47) and 50.00% (10/20), respectively. In the case of food ordering, 16.67% (2/12) of waiters in small restaurants actively asked about less salt, which was lower than that (62.07%, 18/29) in large restaurants (χ² = 7.003, P = 0.015). The sodium content of 200 popular dishes ranged from 5.69 mg/100 g to 1 139.05 mg/100 g, with a median of 378.46 mg/100 g. The sodium content of restaurant dishes was higher than that of canteen dishes (Z = –2.032, P = 0.042). The sodium content of meat dishes was higher than that of meat and vegetable dishes and vegetable dishes (P < 0.001). The sodium content of dishes cooked by stir frying, deep frying, and stewing was higher than that of steamed and boiled dishes (all P < 0.05). Among the dishes, 22.50% (45/200) had the total sodium content ≥ 2 000 mg (equivalent to 5 g salt). The proportion of total sodium content ≥ 2 000 mg was higher in large restaurants (34.48%, 30/87), medium-sized restaurants (33.33%, 6/18), meat dishes (28.81%, 17/59), stir-fried dishes (27.88%, 29/104), and cold dishes (25.00%, 5/20).

Conclusions Some restaurants and canteens in Beijing lack a supportive environment for salt reduction, and the sodium content of some dishes is still high, especially in restaurants. It is suggested that efforts should be made to strengthen salt reduction intervention in the catering industry and bolster the publicity and education of salt reduction.