The difficulty I have with this idea is that they would have to also not count as "carbohydrate".

> Maybe other minerals, salt is some but not 12g of it.

Sodium is reported to the microgram, so we know that salt is 0.5g of it.

For one third of the bread to be "minerals", I'd start to worry that it'd be more like eating a rock than eating bread.

EDIT: it has been brought to my attention that the missing weight is water.