Ketosis, Pro and Con?

I think I have been in ketosis a few times since my surgery because I
don’t eat enough. I haven’t tried to so this, but I do have the
tell-tale coated tongue/bad breath and I think I tend to lose weight
faster than the average person who had surgery with the same doctor.
Should I be worried about the future? i got myself out of ketosis a few
months ago after the doctor yelled at me about not eating enough.