Personally, I feel we hit sticking points in both directions (gaining and losing wieght) purely because the body like to maintain a set balance and it does so by stabilising whenever it can to maintain the homeostasis.
When I initially lost weight, it took a little while before things started to move; once I got to a weight I preferred to be at (not through a set scale weight decision but via exercise and feeling physically better) the body then took absolutely ages to pack any weight on at all...at one point I even thought the body couldn't gain any weight because no matter what I ate I did not gain an ounce, and I ate a lot. Once the scale did start to shift again, however, then it continued to shift until it stabilised at another point.
Many overlook or just don't know that the body is capable of burning off around 400 extra calories, a day, purely to maintain the current homeostasis and that's what it does even if we're not expending extra energy.
36.5 kg /80.3 lb Middle-Finger DL (right hand)...