I know the study which you're referring to, and unfortunately dietary and nutrition science is one of the worst disciplines.
You can find evidence pointing both ways. For instance, it's well studied that in animal models (which can be far better controlled than human populations) high fat diets lead to increased lifespans. The rub here is whether murine models translate to humans, which is not a given.
Keto often has issues because obese people find it as an excuse to continue eating caloric surpluses. It's not magic, and it may not work for everyone. Speaking for myself, doing keto OMAD (one-meal-a-day) is an unbelievable life hack. And my bloodwork backs this up (including a drop in serum LDL after increasing my egg intake dramatically).
I am not referring to one specific study. I have been googling /Google scholaring "diet mortality", "keto mortality", and "low carb mortality" every once in a while and eyed through any new studies.
Now I am not a nutritionist, but I like looking at studies and seeing what kind of things can be confounding. Or try to spot methodoligal errors.
You can find evidence pointing both ways. For instance, it's well studied that in animal models (which can be far better controlled than human populations) high fat diets lead to increased lifespans. The rub here is whether murine models translate to humans, which is not a given.
Keto often has issues because obese people find it as an excuse to continue eating caloric surpluses. It's not magic, and it may not work for everyone. Speaking for myself, doing keto OMAD (one-meal-a-day) is an unbelievable life hack. And my bloodwork backs this up (including a drop in serum LDL after increasing my egg intake dramatically).