The liver functions as the body's 'energo-stat', detecting circulating energy currencies like ATP ratios to regulate energy balance.

“my view is that the liver is the N or go stat of the body I borrow that term from Mark Freedman who wrote an amazing chapter on this in 2008 that has been one of the most influential things in my thinking on appetite but he described the liver as the N ergo stats was an engineer you'll appreciate the nomenclature right it's looks kludgy to someone who's not an engineer to say why would he call it an N ergo stat but in engineering speak that makes perfect sense but that the liver is probably most susceptible to detecting some currency of circulating energy and circulating metabolites ATP would be the most logical thing for it to be sensing so probably ratio of ATP to ADP or ATP to a MP or ADP to a MP something like that”