Why is my logged water intake less than the amount I drank?

This is not a bug, but rather a reflection of the data we use, which is primarily sourced from the United States Department of Agriculture (USDA). The water amounts logged in our system are based on lab-tested values that account for the actual water content present in foods and beverages.

While you might be logging a 600ml bottle of water, for example, the USDA data reflects the precise chemical composition of that liquid. This means that even seemingly pure water can contain trace amounts of minerals and other minor components. Foodnoms logs the scientifically determined water portion of that liquid, which might be slightly less than the total 600ml volume.