Studies, and common sense, show that animals in the wild live longer and healthier lives than those in the zoo because the wild ones have a more natural diet and lifestyle that suits them and has been there for millions of years.
We are not any different. For millions of years, humanoids lived in the wild and consumed fruits, vegetables, meat, seafood, eggs, nuts and seeds.
This has drastically changed in the last 10 000 years. Now, wheat is about 70% of our diets and that is one of the reasons why were are overweight and sickly, unlike the cavemen.
It stands to reason that if we try to emulate the diet and lifestyle of the stone age, to the extent that is reasonable, we will be lean like them and healthy like them.
I have a friend who had psoriasis disease and tried everything. His family is Hindu so they don’t eat meat and paleo was the last thing on his mind. His skin was really affected then he tried paleo. Psoriasis is now history, the skin has healed, he feels great and confident and even wants to meet girls haha.
There are more anecdotes as well as empirical evidence on the health benefits of paleo.
Nowadays I don’t eat a lot of beans, instead, I eat eggs which deliver more nutrition than the legumes which are so hard to digest.
I feel great when I observe a paleo friendly diet and I also get to explore new healthier options.