Are you able to provide a source to substantiate this? :)
I was remembering from the following quote from Dr. Filonov's book: "Water makes up about 70% of body mass, comes
with a drink and food composition, but other than that about 400 ml per day formed in the oxidation of mainly
fat."
I looked up another Filonov quote where "up to 1 liter of metabolic water" was mentioned, but not in conjunction with how much we burn in 24 hours: "from a physiological point of view of the body in complete starvation does not feel substantial
deficit of the liquid, because for every kilogram of a split
fat mass (or glycogen) is released per day up to 1 liter
endogenous (metabolic) water.