They're directly suggesting that food should have labels to let people know when foods are not wholly plant based. It seems they're really arguing that people should only rarely (if ever) eat non-plant-based foods and should avoid foods with animal products in them, because by default we should be eating plants not non-plants.

We didn't eat plants by default, we ate a mixture of plants and meats and other animal-derived products since we lived in caves.

You are now challenging the statement about plants being the "default" food. (Maybe you are not the original responder; I can't tell on my phone UI)

I think you're going to have to back that up with a citation.

For most of history, ordinary people could afford only plant based food. Meat was occasional. Industrial meat production in the West changed the economics of that.

Vegans are not the only people who care about our unsustainable practices. We all should. We could start by properly accounting for the externalities, ecological footprint, worker exploitation, and yes, the built-in cruelty to animals. I think the OP's suggestion to label animal parts is a step in the right direction.

> For most of history, ordinary people could afford only plant based food.

Most of history predates the idea of money.

That’s not true either. It was only plant based when they couldn’t obtain meat. Supplementing plant foods was the default when there was no prey available is more accurate.

Do you have a source on that? I don't think that's an accurate statement, or at least not one you can claim with confidence.

Evidence? We're talking about agricultural societies, too, not about hunters.