https://www.science.org/doi/10.1126/sciadv.aaw0341 https://www.science.org/doi/10.1126/sciadv.aaw0341 "Incorporating data from overfeeding studies, we find evi

https://www.science.org/doi/10.1126/sciadv.aaw0341 https://www.science.org/doi/10.1126/sciadv.aaw0341 "Incorporating data from overfeeding studies, we find evidence for an alimentary energy supply limit in humans of ~2.5× BMR" A good book the topic is Herman Ponzer's "Burn" The main issue seems the surface area of the GI tract.