what happens to your body after repeatedly gaining and losing the same XXlbs?

i dont even know what im asking tbh but ive been in a binge/restrict cycle since like dec 2023 and basically end up losing 15lbs in like 2 months and gaining it all back in another couple weeks. and i keep doing this for the entirety of 2024 and now.

does anyone know how this influences the body? bc some ppl say im just losing muscle mass and then others are saying im losing water weight etc., so im honestly confused.

one thing i have realized is that when i only eat high protein + fiber stuff (for both my binge and restrict periods), I seem to maintain and even build more muscle but in a weird way. like this last binge/res cycle (aka the last 3 months), ive managed to lose my ab definition but somehow gain more muscle definiton in my arms. maybe it's my bdd playing up or smth but idk

anyway if anyone knows, pls satisfy my curiosity!