Where does the assumption that all bodies should work the same way come from?
I do great on high fat but I lost hunger early in life when kids at school stole my food regularly, I can't rely on satiety to tell me if I ate enough or not -following a plan allows me to avoid mindless eating given how good I became at the mindless stuff lately.
Ice cream makes me hungry, and so does my hormonal cycling so apparently I'll have a sort of monthly routine of heavy carb binge.
Coconut oil helped my skin and hair, it had a great impact on dealing with methyl prednisone side effects (which were nasty on my skin and hair) and the only thing with the power to send my life to pot is sugar in all its incarnations (insulin up is a total don't for me). That's me though, it could be useful for someone who has a dynamic matching mine but it could hardly work for a guy trying desperately to gain pound over pound of lean weight.
Meat is a big fav here at home but anything over my 30 gr of protein (a bit more if I'm glycogen depleted) and insulin will go up through the roof. I can't have BCCA after workouts for the same reason, those are no good for me.
Primal eating is a good frame, it's not a low carb eating program but a lifestyle which allows people to live healthy and clean; how many carbs you choose to go with is up to you, your body and your goals.
For me running on carbs is a bad idea, I notice huge improvement when I go VLC which is not common for females -not easy either but I'm tired of having my legs swollen with fluid. Maybe this will change in time, once I get to a more stable situation with less stress and work out a better pharmacological framing with the team following me but I really doubt there's room for tweaking over there.
I know people who deals amazingly good with carbs, even if refined: no insulin resistance there and nothing remotely resembling excess body fat. Is not my case, my body is all I have to work with so I adjust to what makes me feel better.
No limits, only my will and the worlds I build.