[Daily intake of plain water and beverages of primary and middle school students in four cities of China].

Objective: To describe the daily consumption of plain water and beverages of primary and middle school students in four cities of China.

Methods: A total of 5914 students from Beijing, Shanghai, Guangzhou and Chengdu were selected using multiple-stage random sampling method, and 5868 students completed the study from September to October 2011. The information on amounts and types of drinking water was recorded using a 24 hour measurement for seven consecutive days. The amount of plain water and beverages was analyzed for subjects in different gender, grades and cities.

Results: The daily consumption of plain water of subjects was (744 ± 484) ml (68.3% of total drinking water) with statistically significant difference among the Guangzhou, Beijing, Shanghai and Chengdu ((869 ± 528), (818 ± 518), (702 ± 471), and (573 ± 333) ml; F = 113.74, P < 0.05). The amount of plain water in boys (809 ± 534) ml was significantly higher than in girls (683 ± 436) ml (Z = 9.58, P < 0.05) while higher in urban (792 ± 531) ml than in rural (695 ± 427) ml (Z = -6.09, P < 0.05). The consumption of plain water in high school students was the highest (829 ± 513) ml, and that in primary students was the lowest (672 ± 426) ml (F = 55.23, P < 0.05). The average daily consumption of beverages was (345 ± 287) ml (31.7% of total drinking water) and the highest in Shanghai (424 ± 304) ml, then in Beijing (347 ± 303) ml and in Guangzhou (316 ± 267) ml, the lowest in Chengdu (293 ± 255) ml (F = 58.94, P < 0.05). The consumption of beverages for students in urban areas (394 ± 301) ml was higher than that in rural areas (296 ± 264) ml (Z = -14.48, P < 0.05), but no significant difference between boys (348 ± 306) ml and girls (342 ± 269) ml (Z = -1.44, P > 0.05). The consumption of beverages of high school students (356 ± 309) ml and middle school students (360 ± 301) ml were higher than primary school students (328 ± 263) ml (F = 8.37, P < 0.05).

Conclusion: The major drinking water of primary and middle school students in four cities of China was plain water. The amounts of consumption of plain water and beverages varied in different cities, urban and rural and levels of education.