The fact that counting calories is difficult, or that some food labels might be wrong, is not evidence that CICO is incorrect. Just as the fact that different people burn different amounts of energy does not disprove CICO.
I'm astonished how many commenters are desperately trying to find loopholes in simple laws of physics.
I said above, it's not that CICO is wrong. No point I have raised could possibly disprove CICO because CICO is obviously correct from a physics perspective, and I'm not sure if anyone here is trying to find loopholes in simple laws of physics.
I (and most of the other commenters here it seems) keep trying to communicate that it is possible to be both technically correct and simultaneously not useful as a weight loss strategy.
CICO isn't about counting calories, all you have to do is to gradually eat less until you start losing or maintaining the weight you want. CICO guarantees that to work, and lots of people have used that strategy to lose weight, it works 100% of the time if you follow it properly.
It wont work for everyone though, since many people can't make themselves eat less without following some rituals, the problem there isn't CICO but that those people can't implement a CICO diet properly. But that doesn't mean that CICO is a useless concept for losing weight, it just means that those people needs more help to keep their psychology in check.
Saying that CICO isn't useful when CICO is the basis for every single weightless diet in existence is just ignorance or a lie. All weightless diets either makes you absorb less calories by some method, or make you burn more calories, so the first thing when looking at a diet is asking how it relates to CICO. Trying to sweep that under the rug as some old school nonsense principle that has proven to not work just proves how much nonsense there is in nutritional "science".
CICO has limited use. Boiling everything down to a single physics based metric doesn't give us all the information we need.
Knowing what mechanisms and processees go into losing weight can make the journey much more intellectually stimulating, satsifying for the participant and smooth out incredibly rough bumps in the road to losing weight. CICO can't fill this need for tailoring weight loss to smooth out the efficiency losses you get with brutal cuts into one's life and psyche.
Pumping out a single metric and hammering flat all the differences in personal process with psychology and ritual screams of unnecessary suffering. It's probably wrong to use oneself like that.
Very few people live according to the physics based description of what their life should be... However one would derive that idea without hiding or ignoring personal presuppositions?
The "CICO diet" most here are referring to is when people attempt to estimate their "calories in" and their "calories out" and keep the former slightly lower than the latter. To my knowledge this has not been demonstrated to be generally effective, possibly due to the challenges with estimating these values with a reasonable degree of accuracy.
If you're simply referring to the physics of CICO that underpin most diets then I have already acknowledged it is correct.
But being correct does not make it necessary knowledge for people looking to lose weight any more than Hamiltonian mechanics is necessary knowledge to play tennis.
If I still haven't managed to convey the distinction between technical correctness and practical utility yet then I have to conclude this is a gap I cannot bridge and I wish you luck.
I'm astonished how many commenters are desperately trying to find loopholes in simple laws of physics.