Objective: To investigate the drinking behaviors of adults at different time of day in four cities of China in summer.
Methods: A total of 1483 adults aged 18 - 60 years old from Beijing, Shanghai, Chengdu and Guangzhou were selected using multiple-stage random sampling method. The information of amounts and types of daily drinking water was recorded by subjects for seven consecutive days using a quantitative measurement.
Results: The proportion (97% - 99%) and mean (290 - 471 ml) of drinking water of subjects after breakfast, lunch and supper are higher than other time of day (P < 0.01). The distribution of plain water, tea, beverages at different time of day was the same as total drinking water. Among three periods a day, the amount of drinking water in the morning (719 ml/d) was the most, followed by in the afternoon (539 ml/d), and the least in the evening (417 ml/d), the difference was statistically significant (F = 972.55, P < 0.01). The highest consumption of plain water and beverages were in the morning. The consumption of tea in the morning was close to it in the afternoon and higher than that in the evening (t = -52.13, P < 0.01). The average daily drinking water in mealtime was 240 ml, while non-mealtime was 1436 ml, so the difference was statistically significant. Beverages in non-mealtime were higher than mealtime while plain water in non-meal time was higher than meal time (P < 0.05).
Conclusion: The highest consumption of drinking was plain water among three periods a day, and beverages were higher in mealtime while plain water higher in non-mealtime.