This is just more keto pseudoscience. Unfortunately people care more about YouTube videos than what reputable sources say: https://www.niddk.nih.gov/health-information/diabetes/overview/symptoms-causes#type
Not disputing that excess fructose can cause liver damage, but most studies demonstrating this have mice ingesting absurd amounts. This doesn’t happen when you are eating a normal amount of food anyway. Excess water can kill you, but no one avoids drinking water because of this.
It’s the tenant that has no hot water though. The more information they give the landlord, the faster they will get hot water again.