The yo-yo phenomenon does not occur easily once the calibration of the skeleton is completed, unless the external force is applied.
However, the masticatory muscles and the skin layer easily change depending on the activity of the muscles, so yo-yo effect can occur gradually if you neglect the management such as eating habits.
※ If you fail the weight control or pick up eating habits of enjoying chewy and hard food, some yo-yo can resume, so ongoing management is necessary such as proper eating habits and lifestyle.