It's a short term study. Full benefits of Ketosis only become apparent after 4 weeks when the body has undergone a full metabolic shift.
If you go from your link to the PUBMED link in the references:
www.ncbi.nlm.nih.gov/pubmed/26278052
you will see many arguments to the contrary, all citing the short term of the study as fundamentally flawed. They all say that in the long term fat loss is accelerated (with supportive references).
There is no single one size fits all diet. Some people cannot tolerate, or rather have bad side effects from ketosis. I'm lucky, I don't. And so do several others.
You see, you cannot just google a topic and take it as full fact. That's why people out there think vaccines cause autism,dagga is healthhy etc etc.