only really accessible long-term for people who have consistent control over a lot of environmental factors
Long Term Ketogenic Diet
The success of the Ketogenic Diet, any diet, has less to do with "...control over...environmental factors." That is more of an excuse without merit than a fact.
The success of the any diet has more to do with...
"Where there's a will, there is a way."
An individual who's motivated has the drive to "Make it happen".
"Plan Your Work, Work Your Plan"
Planning allows you to override environmental factors rather than being at their mercy.
Good Examples
My success in being on the Ketogenic Diet is driven my a metabolic condition that motivates me.
My success is due to me overriding environmental factors is by planning. I either take "Keto Food" with me or research a list of restaurants menu's in the area that provide me with "Keto Friendly" food.
I don't leave anything to chance or having environmental factors decide my fate, as many do.
Bad Example
My nephew is on and off the Ketogenic Diet due to no planning. He doesn't take "Keto Food" with him. He has no idea of what restaurants menu's in the area are "Keto Friendly. He isn't motivated enough to do what it takes.
He is left to chance, showing up and hoping for the best. He allows his environment to control him rather than controlling his environment. That method ensure failure.
...but don't judge yourself too harsh if it isn't sustainable for you at this point.
Ketogenic Diet Failure
It is a very restrictive, demanding diet plan.
As with anything, the greater the demands, the less likely the majority of individual will be able to maintain it and succeed.
As someone once said, "Successful individual are willing to do what unsuccessful individual won't do."
This take us back to "Motivation". In other words, how much do you want it and what are you willing to do to get it.
Success
When it comes to diets, everything, the primary key is to find something you like and can maintain, long term.
Kenny Croxdale