I have not read all of the comments on the OP, so forgive me if a similar reply has already been published. I just finished reading the “study” which by the authors own admissions, “represents observational data and is not a clinical trial”. I have no problem with the study in general. However, it must be noted that what the study reveals is already known among many of us on a ketogenic diet. That is, if you consume a high fat, high protein diet apart of a nutritional state of ketosis you may be doing more harm that good. Even if you are “cutting” carbs you may not be doing yourself any favors. If you are not a fat burner, you are a fat storer. That just is not going to be a good thing.
All of us know people who seem to defy the metabolic “derangement” that most of here suffer from. They seem to eat whatever they choose and live long and healthy lives. Well, this study is really a study of those individuals compared to us, the metabolically deranged. Ugh, yes those genetic freaks will live longer! I could have told you that! You see, they removed the data from this study from anyone who developed metabolic syndrome. So basically you have those who eat low carb and those who eat whatever, oh and a few who basically eat nothing but carbs. Also, you have to wonder if sampling the population of such a study just a couple of times in yes…25 years! is sufficient. But if it is, so what, again we already know there are people who can eat whatever they want, get no diabetes, no hypertension and have good cholesterol levels. For those of us on Keto, most of our concern is metabolic disorder. For me it was pre-diabetes, pre-hypertension and yes pre-high cholesterol. All of which we headed sharply in the wrong direction. Keto has reversed all of that. So yes, my wife who looks half her age, has perfect health markers will live longer than I will (4.1 years according to this study). At least she won’t have to watch me give myself insulin, or watch me eat myself into a early death. Yeah, I’ll drop dead someday. Apparently sooner than she will. But for now, we are living life more abundantly than ever.