But the article isn't saying it's surprising that you gain weight when you stop the treatment, the surprise is how fast you regain it compared to other treatmen

But the article isn't saying it's surprising that you gain weight when you stop the treatment, the surprise is how fast you regain it compared to other treatments. The conclusion isn't at all obvious so there's no "duh" moment. Why would you gain back the weight that much faster if you lost it with this pill vs. that pill?