I recently posted about doing the doubly-labeled water test for $1,000 and it reporting that I burn over 4,600kcal/day.
Now Brad from Fire in a Bottle has written a pretty detailed biochem analysis of where the DLW method could be inaccurate in "dietary Weirdos” like myself:
Doubly Labelled Water is Less Useful For Weirdos
The tl;dr is this: the doubly-labeled water method really measures the rate of CO2 leaving your body, like all methods of measuring calories out, as CO2 is a byproduct of energy production. It makes certain assumptions to derive your caloric burn from this rate, and Brad has identified ways of “Ninja Water” leaving the body in other ways.
You could think of it like this: unable to measure how much gas an engine is burning, we measure how much exhaust gases are coming out of the tail pipe. Somehow, “weirdos” like me could be producing more exhaust for the same amount of gas burned and power produced.
I don’t think that the whole calories/CICO thing is very helpful for fat loss. Best case, it can show that you haven’t lowered your metabolic rate through excessive caloric restriction or weight loss.
But the nerd in me is fascinated by how the “gold standard” method of Current Real Serious Science could be so wrong.
I think the real takeaway is that the "real science" in areas like nutrition and even medicine is waaay, way less developed than what us nerdy types assume. They present themselves as "serious", and we take that to mean "special relativity" / "quantum mechanics" understanding-of-physics level refined knowledge and epistemology, but really they're at the "four elements make up the world" level of understanding. Basically: no one knows jack shit but it's called science so we take it seriously anyway.
Thank you very much for documenting your trials to ascertain the mechanisms behind weight loss.
I'm sure that there are many people who are fascinated reading of the various tests/trials you subject yourself to in order to understand this.