https://www.discovermagazine.com/health/fat-cells-can-retain-a-genetic-memory-even-after-weight-loss
Research shows that genetic reasons are why some dieters experience the Yo-Yo Effect.
Sometimes, good memory can be bad news.
It turns out fat cells have excellent memory. Researchers published a study in Nature that explains how that memory works and why it is so persistent. The work describes the genetic and cellular mechanisms that make the "Yo-Yo effect," a common phenomenon where a person can lose weight, but it returns right away.