Yes of course if you take two groups of people who eat a lot of carbs and give one carbs and one fat, the carb one will win. It definitely takes some time to completely become adjusted to running on fat but once it happens, it is far preferred in my opinion.
Carbs go in, insulin goes up, carbs run out, insulin sticks around without sufficient glucagon.
Body is freely burning fat with the knowledge that food is plentiful. High glucagon, low insulin.
Fat adaptation pretty much has to be a conscious choice. You can't take people who are not fat adapted and expect them to thrive on fat right away. It's dishonest of the researchers.
Stabbing conventional wisdom in its face.
Anyone who wants to talk nutrition should PM me!