I'm eating a lot fewer veggies and fruits, far more meat and eggs, and I feel much more energetic, very noticeable. I'm inching my way, potentially, into the carnivore diet. I'm also immersing myself in some of the contrarian books on the topic.

For a takedown of veggie "superfoods", you might find the book Toxic Superfoods interesting. Quick summary - oxalates (and other compounds in plants) can cause serious health issues over time, and acute health issues for some people. This is especially a problem with some of the plant products regarded as superfoods, especially spinach, almonds, and chia seeds. Those are some of the worst in oxalates, and I've eliminated them completely from my diet.

As far as I can tell the "vegetables are poison" thing is a garbled version of the finding that vegetables produce compounds to discourage animals from eating them. The problem with the poison claim, is that we adapt to those compounds.

It's also too broad of a claim, because many plants rely on being eaten in order to propagate. Those plants are adapting to be more appealing rather than more repellant.