The main psychological irregularity of ketoers and various other similar groups is holding the unproven assumption that the human species has evolved to be very low BMI by just eating healthy food. I mainly blame Gary Taubes and other gurus of the community because they seem to push the belief that since they, personally, are how they are by how they are dieting then everyone else must be identical to them. I don't blame them too much though since the bulk of what they say is true.

In reality, it's pretty obvious that even the ancient hunter would not just stop eating to the point of having no excess fat, in the modern sense of slim. He would obviously eat more to compensate for potential downtimes. He would become chubby for a while. Sure, he may have been slim for a lot of the time, but that may be because he actually did have food shortages, hence the "feast or famine" instinct in the first place. Nowadays there is virtually unlimited food.

Obviously, low carb diets do bring the weight down in most cases. People the size of a planet can become just chubby by doing nothing at all. But the assumption that everyone will become very slim in the modern sense of a fashion magazine slim is just wrong. The norm in keto is that people stall after a few months to a weight that they consider more than it should be even if they lost a lot at first. Those communities should seriously put some thought on the "feast or famine" instinct that makes perfect sense that it existed. Sure, it didn't make people sick, and they may not make them today sick (maybe) but it won't easily make them fashion-magazine thin by completely going ad libitum.