When meat companies buy into veggie burgers you know things are changing. Tyson, the largest meat processor in the US is investing in Beyond Meat, a company that creates burgers not from beef, but plants the New York Times reported in October.

Meanwhile in Germany one meat producer is planning to have at least 30 per cent of its sales as vegetarian products by 2019, according to food industry journal Food Navigator.

It's a sign that more of us want our protein to come from plants but it's also something else: a sign of a collaboration between two opposite sides of the fence - an industry that kills animals for profit and one that caters for consumers who'd rather not eat food produced in a slaughterhouse.

That's not such a bad idea, says Marta Zaraska, author of Meathooked, a new book looking at our hard-to-break love affair with meat. If our goal is to improve health, boost our chances of combating climate change and reduce animal suffering, then a purist vegetarian approach may not be the best way, she argues.