Let's try this. During my last 7 day dry fast I lost 21 lbs or 9.53 kilo. Let's assume that 40% of it was water weight, which equals to: 3.8 kilo. The remaining 5.73 kilo are divided between fat and lean tissue, both of which constitute metabolic water, since metabolic water does not come just from fat but from lean tissue as well. Hence, I produced an average of 5.5 to 6 kilo (liter) of metabolic water in one week, or an average of .8 liter of metabolic water per day. Now had I been heavier then where I started I am sure I would've produced more. However, my fat reserves have dwindled sufficiently since after my 40-day fast and my subsequent dry fasts...:)