A lot of this reporting is a big misunderstanding of statistics.
As the study says
About 45% of the population had zero beef consumption on any given day, whereas the 12% of disproportionate beef consumers accounted for 50% of the total beef consumed
Now just as a thought experiment, do you think that almost half of the US never eats any beef? No, of course not. But on any given day? Sure, quite possible. People's diets vary.
A randomly selected person might have a McDonald's hamburger for lunch and a steak for dinner and be part of the 12% on the first day but then eat mushroom ravioli for lunch and pizza for dinner on the second day and be part of the 45%.
And there might be certain demographics that are more likely to make up that 12% on a given day but that doesn't mean there's a particular nonchanging group of high consumers.
I'm not going to dig into the study here but just as an example, let's say Dog Breed X is 1.5 times more likely to bark than Dog Breed Y is. You can't hear a dog bark and say "Ah it must be Breed X then!", you can only say "Ah, it's more likely from Breed X than Breed Y".