[fatso83]

This is known for decades. If you drop too fast over too long period of time your metabolism changes base burn rate and you will have a hard time losing fat/staying the same weight once your normalize your diet. There is a reason diets like PSMF at restricted to 1-2 weeks. Not healthy over time.

[JamesBarney]

I've now read several studies about successful long term weight loss maintenance. And none of them mention speed of weight loss as a factor. The Wikipedia article on it doesn't mention it.

Also here's a study that suggests the exact opposite, that rapid weight loss is correlated with long term success.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3780395/