This is really interesting. It's the list of the top ten "Most Googled Diets of 2013". I may have to Google a few of these myself since they sound interesting and I don't know much about some of them. This link gives a brief overview of each one.
It's a diet that tries to mimic the way that the cavemen would have eaten. Basically meat, fruit and veg and no grains as they wouldn't have been able to process them. It's quite interesting to read about but I think
I would miss pasta and rice too much to commit fully to it!
Someone started a Paleo diet thread awhile back. (Sorry, don't remember who.) It's a couple pages back on the thread list. There was a link to a site and I remember I read that and it sounded like a good diet. It's like Atkins in a lot of ways except with more natural foods. It would be hard to stick to. It's pretty strict.