There could be more to it. There's a hypothesis that microbiome changes could be a contributing factor[0]. Restricting food intake is similar in that it reduce

There could be more to it. There's a hypothesis that microbiome changes could be a contributing factor[0]. Restricting food intake is similar in that it reduces stomach capacity[1], though almost certainly not as drastically as surgery. Lots of people have already mentioned fasting in this thread; I'll add an anecdote that for a few days after a fast, I get full much more quickly. [0] https://biodesign.asu.edu/news/dramatic-shift-gut-microbes-and-their-metabolites-seen-after-weight-loss-surgery https://biodesign.asu.edu/news/dramatic-shift-gut-microbes-a... [1] https://www.ncbi.nlm.nih.gov/pubmed/8561056?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=1 https://www.ncbi.nlm.nih.gov/pubmed/8561056?itool=EntrezSyst...