Plain foods like white bread, potato waffles, plain pasta or with a little cheese are very simple and comforting in an overstimulating world.
There's no issues with strong flavours, foods touching and causing stress or weird textures.
I typically eat an extremely varied diet, but when in burnout I eat plain pasta with a bit of grated cheese or toast. It soothes my brain.
I will also occasionally go through phases where I will eat the same meal for about a month and then not eat it again for a very long time.
It is like I get stuck on a wheel and it is the only thing that will satisfy me and I will think about it all day.
There is also an aspect of a lot of ND people needing to nurture "the child within" and having aspects of things that are comforting like a soft toy, adult colouring books, Disney or simple foods.
The world is loud, scary, abrasive and stressful.
Simple, comforting activities and foods help us soothe and cope.
I can't explain it in technical terms sorry... and obviously not speaking for all ND people.