(I just wanted to thank you for this post, as I've seen a few mentions of the Paleo diet, but I always read it as "puh-Lee-Oh" diet, thinking it was named after someone (like Atkins) or a place or something. Now I understand that it's Paleo (as in paleolithic) and I feel silly. But at least this misunderstanding has been corrected. Thanks)

They are all just trend diets, really. The real studies show that these fad diets are more dangerous, even the ones "endorsed" by doctors. Speaking of which, you should really be asking yours for help not people online. There is no such thing as "one size fits all", and diets are not an exception to this rule. You need to worry about what your body needs, not what someone else wants to make money on. Naturally your body will crave flavors, but due to the junk food emulating a lot of the flavors sometimes it's hard for a person to know if it's really the Snickers bar or the peanuts they are craving, thus you ask your doctor. All the diets, Jenny Crag ... Atkins ... Paleo .... all of them, are just fads designed to make money, and some are even dangerous, but skirt the laws, there is no regulation for them, none at all. They don't even have to be scientific, but they sell more if they sound scientific. Cave men ate pretty much what they craved and could catch, they just ate it raw, and now we can't eat raw meat, not the animals you can buy in the store anyway, except fish, and then that's risky today. Our physiology is very different today from that of a few million years ago, it's different from that of a few thousand years ago even.

On the "they didn't live very long" point, I just wanted to say that this is not, in fact, true. AVERAGE life span was roughly 30-40 years, but this is because some ridiculous portion of children died before they reached the age of one, and then another significant portion died before the age of 20. In the Middle Ages, anyway, if you made it to 20, you stood a very reasonable chance of making it to your 70th birthday.

It has nothing to do with poor nutrition, rather more about the lack of modern medicine. Many women died in childbirth, and lots of babies, too -- just think of what our world would look like without the benefit of contemporary neo-natal medicine.

Cavemen didn't live long because they lacked access to antibiotics and proper hygiene and probably were prone to dying in preventable accidents, not necessarily because they had a poor diet.

There are studies out there that show that refined carbohydrates and simple sugars do more to increase bad cholesterol and triglycerides than eating meat and other fat- and cholesterol-rich foods. I can't direct you to them because I've really only heard about them secondhand from my sister who has a Master's in nutrition.

I think the main differences between Paleo and Atkins is that Paleo disallows consumption of dairy and emphasizes lean meat while Atkins disallows consumption of nuts and seeds and discourages fruit (at least in the beginning stages).