The foundation of Mark Sisson's primal diet (lots of fatty meat, some vegetables, nuts and seeds, limited fruit, and no cereal grains) is that we should eat what our ancestors ate. According to him, this means lots of meat and fat and very few carbohydrates. These are the foods that our ancestors thrived on and these are the foods that we thrive on today.
Let's start by analyzing the first part of that statement: Did our ancestors really thrive on animal flesh?
Look to Your Ancestors
Here are just a few points that refute Mark's argument that our ancestors relied heavily on meat:
#1: Humans Were Gatherers First, Hunters Second
If I learned one thing over and over again from the numerous anthropology courses I attended in college (anthropology was my minor), it's that humans were primarily gatherers. Over 70% of the foods we consumed were plant-based. And this makes perfect. We are not very adept at hunting. We have dull nails, flat teeth, and we aren't very fast. It took a lot of work for us to track and take down an animal, even a small one.
#2: Heavy Meat-Eating was Limited to the Ice Age
It is very likely that our ancestors (at least some of them, depending upon the region), lived on a large portion of meat. And even though most vegans may scoff at it, this was a GREAT thing for our species.
If we had not created new tools for killing large animals, (such as long spears with sharp, curved points all over the blade that did a great job of taking down large prey while we remained at a safe distance) rather than relying on small tools for scavenging, and if we had not learned how to track and hunt these animals effectively, our species would not have survived the harsh conditions of this particular glacial maximum (aka the Ice Age).
But the fact remains that this was only a portion of our time on the planet. Anthropologists agree that the rest of our existence as hunter-gatherers was spent eating mostly foraged foods.
#3: Wild Meat was Lean Meat
Even if we did subsist on lots of animal flesh during the Ice Age, this flesh came from wild animals (e.g. elk, reindeer, and mammoths). These animals were forced to traverse the land and fight for their food, just like our ancestors did.
As a result, they were fit and lean (averaging 15% body fat) unlike today's fatty domesticated animals which Mark and paleo supporters promote eating (even when trimmed, beef sirloin is still almost 40% fat). And really, I'm being lenient when I say that humans likely ate mostly meat during the Ice Age. Anthropologists still argue about this point, some claiming that we continued our plant-predominated diet. I think the evidence suggests that we did eat quite a bit of animal flesh and that this helped us tremendously during the harsh weather conditions, but I'm no anthropological expert. :)
#4: Low Fat was the Norm
Anthropologists also agree that the diet we lived on as hunter-gatherers was low in fat, staying within the 10-20% range. Meat was a rarity (and as I already mentioned, these animals were lean) and fatty nuts and seeds were only available for part of the year. Everything else, i.e. fruits and vegetables, are low in fat. This is very different from Mark's recommendations of eating 50%+ of total calories from fat, most of this fat coming from animal flesh.
#5: Hunter-Gatherers Ate Meat, Pastoralists Ate Milk, Eggs, and Cheese
While it's clear that humans have always consumed some meat, it's also clear that we did not consume any animal by-products (e.g. dairy and eggs) until we became sedentary and began domesticating animals. Why Mark thinks that consuming butter and cream correlates to a hunter-gatherer diet, I haven't the foggiest.
Look to Your Anatomy
Regardless of the immense research and fact finding that has been done regarding human evolution, the simple fact remains that we were not there to witness it. We will never know for sure what really happened.
So since the past will never be fully understood, is it really a good idea to base an entire diet around what we think our ancestors consumed? I don't think so.
I think it is a much better idea to look at what we do know, and that's the human body as it exists today. And it just so happens that everything we know supports a high carb lifestyle, not a low carb one.
#1: "The Currency of the Body is Glucose"
This is how fellow high-carb lover Frederic Patenaude put it during a lecture and he's absolutely right. Your whole body runs on carbohydrates, specifically the simple sugar glucose. Everything you eat has to be converted to sugar for you to fully digest it. This fact alone completely plunders the low carb argument. But there's more...
#2: You Are Not a Carnivore
Nothing about your anatomy or physiology suggests that the optimal food for you is meat. Quite the opposite, in fact. Your flat teeth, flat nails, long digestive tract, and inability to produce vitamin C practically scream that the foods which support you best are plant-based.
#3: Meat Causes Cancer
The research is clear. If you want to avoid common cancers (e.g. colon cancer, rectum cancer, breast cancer, and prostate cancer) and other diseases of affluence (e.g. heart disease and diabetes), you have to consume as little animal products as possible.
Don't believe me? Check out The China Study by Colin T. Campbell.
#4: Ever Experience Withdrawal Symptoms From Fresh Fruit?
When a person gives up animal products, particularly dairy, he or she experiences withdrawal effects. Similar to when people give up alcohol, nicotine, caffeine, or cocaine, it is common to experience headaches, fatigue, runny noses, and break outs when transitioning to a meat-free diet. And after the detox is over, their health invariably IMPROVES! If animal products were good for us, we would not see this kind of negative reaction or the positive results that follow when we eliminate them from our diet.
#5: Ketosis is a Last Resort
Frederic also pointed this out during his lecture. Ketosis is a process by which your body burns its own stored fat for fuel. This is a way for your body to avoid consuming its own vital organs for as long as possible during times of famine. This is specifically why people can fast for long periods of time without keeling over.
Purposely entering into ketosis, which is what Mark's low carb diet forces the body to do, is not advantageous. Ketosis is a survival mechanism, necessary in times of famine, and should not be viewed as a viable weight loss or health strategy.
Bottom Line
Human beings thrive on whole food carbohydrates, not fatty meats. These are the foods your ancestors thrived on and these are the foods your body thrives on today.
"healthy life":live healthy with a normal way without having to design a strict diet which could be difficult to self
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