It's not even new information -- it has been known by historians for decades that most non-elite Romans had no ability to regularly consume meat and they existed on a heavy carbohydrate diet supplemented by seafood when they could get it.

It's one of the things remarked on by contemporary Romans about their Germanic and Celtic foes -- that they ate so much meat, that they used 'disgusting' animal fats (lard and butter) instead of olive oils in their cooking. And that they were much taller. Likely because of higher meat and dairy consumption over several generations.

The Roman agricultural economy could not support high meat consumption.