I was wondering which aspect is particularly unhealthy...and what are the specific health effects? Here is what I understand to be true... Being too dehydrated can lead to Kidney failure. Ex: Daniel Cormier Obviously Kidney failure is bad. But if your kidneys don't fail...is dehydration rapidly aging you? Are your kidneys getting somewhat damaged every time? For instance...Conor was an obviously extreme weight-cutter at 145...has he done significant damage to his kidneys or aged exponentially from these cuts? Will his career be cut short? Or is he fine because his kidneys didn't fail? Is it unhealthy to drop from reasonably good shape...AKA 17% bodyfat down to 8% bodyfat on a regular basis? I think most people yoyo in weight with the holidays...the fighters just have lower %s in their peaks and lower averages than the general public.