“...avoiding wheat, barley (malt), and rye in this society is a 24/7 concern.”
OK, real question here, no blarney. All of the grains listed above are used in the distilling of my favorite adult beverages.
Is there a carb-related danger in liquors produced from grain? Yes, I know about the `empty calories’ in alcohol.
Of course you might end up with some new problems, but that's a totally different sort of thing.
Stay away from beer ~ even rice beer is flavored with barley malt. Many things are flavored with barley ~ I'm particularly susceptible to malt so I really watch out with so-called chocolate candies.