You are right by saying that is dangerous, as with water, minerals comes out from your body as well. That is why we see broken bones so often. https://www.youtube.com/watch?v=klFeEHpYfqY here is a video for you about extreme weight cutting.
That was very interesting video. Conor McGregor looks like a dead man in that cut but the last guy was really a walking dead. As far as I know, MMA fighters aren't paid well and they struggle with money, boxing pays much better. I think that weight cuts must be much harder for them than actual fights. Extreme weight cut is intense, that is the moment when all your sense heighten and even a smell of the good food is euphoric.Do you know kids question for trolling: "What is more heavy? 1 kg of iron or 1 kg of feathers". 
That is our case. Sugas has longer bones, more meat. Simple. It does not matter if someone looks smaller or bigger than his opponent. For UFC matter that you show your weight on scales, then you free to have any weight during the fight.
You made me find a perfect example how unfair UFC weight system is
Here is a picture of Jared Cannonier. He fought in 3 different weight classes. Not simultaneously, but technically, you can prepare to fight a guy on a right, and get a guy on left as an opponent That is more power, more damage, more control.
Yeah, I know that question, someone has asked me and my friends when I was a kid but the question was, which one is heavier, 1kg of iron or 1kg of cotton. I'm expressing my emotions when I say that I can't understand how they are the same weight, I'm saying that he is too big and his weight cut must be awfully terrible. That is our case. Sugas has longer bones, more meat. Simple. It does not matter if someone looks smaller or bigger than his opponent. For UFC matter that you show your weight on scales, then you free to have any weight during the fight. You made me find a perfect example how unfair UFC weight system is
Here is a picture of Jared Cannonier. He fought in 3 different weight classes. Not simultaneously, but technically, you can prepare to fight a guy on a right, and get a guy on left as an opponent
That is more power, more damage, more control. Is this the picture of the same guy? Are the numerations correct? He looks much younger in 2024 than in 2016
I didn't know if weight had such an impact on a person's appearance in terms of visual age.