Just what is the Paleo Diet all about? Do you need to eat like a caveman, and carry a club? Or is there more to it? Here are the details.
The gist of the paleo diet is based in common sense. If you had a lion as a pet, and you tried to feed it only grass, it would die. Its lion body had been designed over countless thousands of years to live on meat. Its body wouldn't know how to process a diet of only grass. If you had a cow as a pet, and tried to feed it only beef jerky, it would also die. Its four-part grass-digesting stomach would not be able to handle a diet of pure beef.
So, in the same way, our human bodies have been evolved over thousands of years to ingest certain types of foods. These did not include genetically modified objects or artificial chemical concoctions. Our bodies were tuned over time to run optimally over a diet of berries, herbs, meats, fruits, and so on. That is what our stomach expected to ingest, and what our muscles and other cells expected to work with.
The paleo diet feels that grains simply should not be eaten, because humans only artificially began eating grains fairly recently. Many of us are intolerant to gluten, because it wasn't a natural part of our diet. Others are sensitive to lechtin, another component in grain.
Similarly, the paleo diet is against any added sugar. Our ancestors didn't have access to sugar to put into every food they ate. In modern times sugar is found in ketchup, mustard, salad dressing, peanut butter, jelly, you name it. But even only a few hundred years ago this wasn't true. If people wanted something sweet, they'd eat a piece of fruit that had natural sugars in it.
Paleo tends to be against milk consumption in adults, since in most societies milk was only drunk by babies who of course needed it. Many adults are lactose intolerant, and this is natural. Adults just aren't meant to ingest milk.
So the focus here is on fresh, natural food. Grass fed meat (no grain of course). Organic vegetables. They don't "count" carbs or anything else because the theory is if you eat healthy foods, stop when you're full, and balance your diet, that everything will work out naturally.
In general much of the paleo diet is just like the low carb diet. The low carb diet isn't as anti-grain as the paleo diet - with low carbing one would be OK eating whole wheat grain for example. But many low carbers avoid all grains. Both low carb and paleo emphasize fresh, healthy foods prepared as naturally as possible. They try to stay away from artificial foods and sweeteners. Both avoid sugars.
One challenge with the paleo diet is that there is no "guidance" at all on eating amounts. You are normally told "eat as much as you want" with the assumption that you just can't eat enough broccoli to cause a problem. However, many people have a variety of issues with eating. They comfort eat. They mindlessly gorge. A key reason they are trying a diet is to change their eating style. So with this being so "loose", it might not be a big help. If someone is told "eat as much as you want!" and they gorge all day long on oranges and bananas, they can easily gain weight and have nutritional issues too. Lots of food are both natural and chock full of carbs and calories. Heck, lard is a natural substance and could be very bad if eaten all day long.
Another challenge is that it is, sadly, expensive to eat in a healthy manner. For some reason organic foods can be both hard to find and extremely expensive. The same for free range meats, grass fed meats, and other healthy things. If you have farmer's markets near you that can be a great help - but many people live in inner city environments where they have no access to farmer markets nor to inexpensive food. If they tried to eat completely paleo they might spend their entire income just on food and not have any left for shelter or transportation.
So I would say that the paleo diet has a lot of valuable information in it. I wholeheartedly agree we should all strive to eat natural, organic, foods as much as possible. I can appreciate the quest to cut out milk and grain from one's diet; there are plenty of other food options out there. We should all eat more vegetables and healthy proteins. My caveat is that for a person not fully in tune with their eating and health needs, that the paleo diet might not provide enough guidance to help them figure out balanced menus, portion size, and other components of healthy eating.
Lisa Shea's Library of Low Carb Books