The amount we consume is far more than that we see, because a large quantity of water is hidden in products or food, which is called "water footprint".
According to a research conducted and published in Journal of Hydrology, Hong Kong's food related water footprint is 4,727 L per capita per day, equivalent to taking shower for 7.87hours continuously*. This is indeed much more than its direct water use of 130L per capita per day.
The reason of such a high figure is because of Hong Kong's typical urban diet, characterised by a high intake of water intensive products such as animal products and sugar. The current meat consumption in Hong Kong is 126 kg per capita per year, which is extremely high and leads to high water footprint produced.
If Hong Kong people consumed more vegetables and fruit, and reduced consuming sugar, crop oils, meat and animal fats, this would not only become a healthier diet, but would also result in a reduction of the water footprint of 40%.
*Assuming average flow rate of WELS Grade 1or 2 shower to be 10L/min
Source: Water Supplies Department, Vanham, D., et al. Cities as hotspots of indirect water consumption: The case study of Hong Kong. J. Hydrol. (2017), https://doi.org/10.1016/j.jhydrol.2017.12.004