This has been known for a long time. But what it does show is that the body never acclimatizes or resets its 'set weight' to the new weight, but rather fights virtuously to return to its old weight, even after many years.
Feels tricky to compare rebound from a quick fix with rebound from a process that takes more effort. How do you account for the people who wash out by not being able to follow the high effort process?