That's not true at all. We're eating more meat than we did 100 years ago sure. But looking back significantly further than that, it's estimated that hunter gatherers got about 65% of their calories from animals, compared to much less than 20% we get today.
See my reply above for references.
EDIT: Besides, I can tell you from what I know on how people were living 50-70 years ago (grandfathers for example) that meat was expensive during their youth and that they only ate it once or twice a month, certainly not every single day like we do now. So I'm not sure where you got the impression people ate so much meat in the early 1900s while it defies all conversations I had with people who lived in that era.
I said this in the comment you're replying too "We're eating more meat than we did 100 years ago sure". I'm agreeing with your assertion that we eat more meat than we did 100 years ago. 100 years ago we ate significantly less meat than our hunter gatherer ancestors did.
>I'll check you references later, but I'm wondering where the hunter gatherers got so much meat before they had industrial meat factories that we have
They didn't need industrial farms because there were far fewer people. They hunted animals, which were relatively abundant. Meat is much more calorie dense than most plants.
Hunter gatherers didn't have agriculture, so many of the plants we eat today weren't yet domesticated. They lacked entire categories of food that we have today.
The largest percentage of daily caloric intake today comes from grains--hunter gathers didn't farm grains, so they had to get the largest share of their calories from something else--meat.
>Besides, percentages is one thing, absolute intakes are another, too.
An average adult male can't live long term with fewer than around 2000 calories per day (A very active hunter gatherer would require a far amount more than 2000 per day). The average American male eats about 2700 calories per day.
Let's take the lower end estimate for 2000 calories per day for a hunter gatherer. At 65%, meat accounts for 1300 calories per day.
At 20% of 2700 calories, an average American male gets 540 calories per day from meat.
So 1300 for the hunter gatherer vs 540 for the average American male. Almost 3 times as much. Even in absolute numbers, the hunter gatherer at much more meat.
It cost a lot of time/energy to hunt, for sure. But that's basically all they did. And reading descriptions of say, the Americas before European colonisation, meat was plenty despite industrial breeding, or any breeding at all.