---Apologize if this comment offends you, I didn't read the whole article (' ; ω ; `)---
But actually, when we absorb enough sugar, our brain will stop let us feel happy if we continue eating them.
---As I know---
It's more like because our brain will stop notice that we have already absorbed enough sugar when we are eating something that is mixed by sugar and fat(usually 50%), such as donuts.
---conclusion---
it's not only because of sugar