Is drastically restricting the amount you eat equivalent to gastric bypass? Or is there something more?
Put another way: is gastric bypass a way of solving the psychological problem of eating too much, the lack of will to stop eating?
Put another way: is gastric bypass a way of solving the psychological problem of eating too much, the lack of will to stop eating?
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-a...
[1] https://www.ncbi.nlm.nih.gov/pubmed/8561056?itool=EntrezSyst...