Jane, am currently talking with people on Youtube who swear they lose more while dry fasting versus water fasting. Nobody has specifically said “three times as much,” but they insist it’s definitely “more.”
The “dry fasting is 3x faster than water fasting” thing is very pervasive, though, as a claim. Among the reasonable-sounding people who swear they lose fat more quickly on a dry fast, there’s a morass of some outright falsehoods propagated by dry-fasting advocates, a lot of wishful thinking, and the fact that the length of the fasts are so short as to render weight measurements useless as a fat-loss gauging tool. Any truth in there, if it exists, is swamped by the other factors.
Totally agree - I see no way of getting around what is apparently quite a hard limit on fat burning, a la “A limit on the energy transfer rate from the human fat store in hypophagia.”
As far as making water from fat - that could have a meaningful effect on our hydration while dry fasting - it does not happen (from everything I’ve read). We start off by consuming 3 water molecules in the breaking down of every triglyceride molecule, so we’re at a net negative thus far. Eventually, some water is indeed created, as the byproduct of cellular respiration/metabolism, but the vast majority of that goes to the lungs and is exhaled, along with carbon dioxide.
A white fat cell has a very thin layer of cell membrane around the outside that contains the cytoplasm, nucleus, mitochondria, etc. - the normal cell parts. Then there is a relatively huge droplet of fat in the middle. Very little water, overall, and the cell cannot afford to lose it from the cytoplasm. It’s a common thing to hear the like of “There is water in fat and our body rushes to get it while dry fasting.” Here too, as far as I can tell, that’s just wrong.