In defense of the linked article, they're not saying volunteers should stay on the diet indefinitely -- they say "at least 4 weeks." And all the examples they

In defense of the linked article, they're not saying volunteers should stay on the diet indefinitely -- they say "at least 4 weeks." And all the examples they cite are people doing it for X weeks and then transitioning to a diet that's more varied (but still restricted compared to what they were eating before).