Answer:
be honest , very kind
i would approach the situation in a very calming way, tell them how common or rare their results are, tell them all the ways to cure and better themselves if possible.
I am not a medical professional
what are you studying?
This is when you lose weight, gain weight, then lose weight, then gain more weight than you had before!! It can go on for a very long time. Many obese people suffer from this.