I haven’t read about the Inutie or whatever initiative, but am a scientist. Absolutely correct thinking goinng on about sampling bias and all of the variable behavior (diet and exercise), variable health issues as to why people do keto (weight loss only, diabetics, liver disease) and the variable genetic background for each of us (keto to reduce blood lipids due to familial risk of heart disease, strokes, cancer, hyperlipidimemia) etc.
Now, if you had huge bucks from the NIH or an Angel investor, a huge nation consortium to be able to control for some variables, like age, gender, ethnicity, smoking, medications and medical history and were able to do a completely @prospective @ study (enrolling everyone who starts a keto diet and follow everyone for a few years regardless how how long they stay on keto) and THEN study everyone…
Then you might be able to get some useful data on some sections of participants.
But, who is going to pay for a study like this? It would have to be a group who cares about finding ways to reduce morbidity from obesity. Maybe the NIH or an Angel, but Pharma would lobby against funding a study that might lead to an obesity cure UNLESS they can figure out a way to make money from a drug that comes out of a follow up study of those who lose weight and why.