The Paleo diet comes from the philosophy of how humans have may have eaten in the Paleolithic era.

The homo Erectus, and then homo sapiens, the latest version of a hominoid came around 250,000 years ago; most researchers in paleontology and human evolution agree that there is very little difference between the DNA of the home sapiens, and our DNA today; yet, 70 percent of the foods comprising our modern diet started in the last 10,000 years.

According to this idea, whatever they ate back then would be the most appropriate type of food for us to eat today because we have the same DNA as they did; the DNA codes for enzymes, and enzymes are what you have in your body that break down the food and different types of food require different types of enzymes.

You can’t digest milk the same way a calf can, simply because you don’t have the cow enzymes and the gut bacteria that synthesize the enzymes; an enzyme is a catalyst that fits into specific molecules and helps us break down and metabolize that food.

With this thought in mind, if our ancestors had a particular set of DNA to code for a particular enzyme, then given our genetic similarity, it would make sense that our enzymes and digestive system would be suitable for the same foods they ate back then.

So, what would be OK to eat on the Paleo diet?

Well, anything that our ancestors had access to, such as beef, lamb, chicken, turkey, pork, anything that they could pull out of the ocean (fish and seafood: salmon, trout, haddock, shrimp, shellfish), catch and kill and eat would be all right; they also probably had access to some fruits and some vegetables, depending on the season. They likely would have been able to find some eggs, and they could also pick nuts and seeds.

They could dig up some roots, such as tubers like sweet potato, potatoes, yams, and turnips; early versions of all of those foods would be available to our ancestors. This is the argument that supports the theory that those are the food we should eat.  Not any modern synthetic foods with chemicals in. For example, foods that were not available 10,000 years ago include:

Sugar and high-fructose corn syrup: Soft drinks, fruit juices, table sugar, candy, pastries, ice cream, and many others.

Grains: Includes bread, pasta, wheat, wheat, rye, and barley (yes grain existed but was not processed in the way we do it today).

Legumes: beans, green beans, soybeans, black beans, peanuts, lentils, and many more.

Dairy: most dairy, especially low-fat.

Some vegetable oils: Soybean oil, sunflower oil, cottonseed oil, corn oil, grapeseed oil, safflower oil, and others.

Trans fats: Found in margarine and various processed foods; usually referred to as “hydrogenated” or “partially” hydrogenated oils.

Artificial sweeteners: Aspartame, sucralose, cyclamates, saccharin, acesulfame potassium.

Highly processed foods: products labeled as “diet”, “low-fat” or food that has many additives; including artificial meal replacements.

Humans had no way to access those foods, and each year the food we are offered seems to be changed in some way, whether it be from farming or manufacturing, but the Paleo diet advocates that we should eat it in its original form.

But what is the perfect mix of macronutrients?

Before determining the best ratio of macronutrients for a paleo diet, we need to understand that access to food depends on where people lived 2.5 million years ago up until the formation of ‘modern’ agriculture about 10,000 years ago.

In the northern parts of the world where it was colder, they had fewer fruits. When they had a shorter growing season, they would rely less on carbohydrates, probably as little as 10%, and could rely more on fishing.

So with fishing and hunting seals, they would probably get 60% of their calories from fat; if you lived in the tropics, you would have more fruits, vegetables, longer seasons, and so forth.

So you might have 40 percent; this represents a moderate, almost high carbohydrate diet with no processed sugars.

As there was no refrigerators or global distribution of food, there was a lot of variation from day to day and between the seasons; our ancestors had periods of feasting and periods of famine.

During the feasting, they probably ate low to moderate carbohydrates, and when there was not so much food around, they most likely ate low carbs or probably zero for long periods.

When they did not have access to food for a couple of days, they would naturally be doing intermittent fasting, something that is gaining popularity now.. That is how humans have eaten for as long as we have existed. It could be argued that it is the way we are supposed to function as humans, and the health benefits seem to back that up.

Since 1952 several scientists, doctors, and anthropologists like Richard Mackarness, Walter L. Voegtlin, Stanley Boyd Eaton, Melvin Konner, and more recently Loren Cordain, have published the breakdown of ideal macronutrients for humans. They have done a lot of research on this and looked at hundreds of different primitive populations, where they lived, their ancestors, what they were likely to eat, and so forth.

Most of them agree that the numbers that our ancestors, on average, probably ate around 39-40% fat, 38-40% protein, and about 23% carbs. Basically, twice as many calories from fat and protein; this, in essence, is a low-carb diet.

Does It Work?

I think the Paleo diet idea is a fantastic foundation; however, we also need to look at our sleep cycle, activity levels, and how we respond to stress. Our whole stress response developed to give us a survival advantage.

We were supposed to have a fight-flight response to run away from a threat to find when safety in a cave or a tree where our bodies could settle down, so there were a lot of differences between the fight-flight and relaxation.  Today, our stress is very different, so we are not living the way our bodies were designed.

We have a lot of low-grade stress that keeps going hour after hour as we sit in front of computers with deadlines. We sit in traffic, have arguments, watch the news, we listen to politics. We have all these little things that set off stress responses, and we are not designed for those types of things.

Everyone should look hard at the Paleo diet to get a good premise to understand where our roots are, we should understand that people ate a certain type of food and that food was always whole and unprocessed. From that point, you can establish your health goals, and weigh,t taking into consideration the current state of your body to insulin resistance, blood pressure, blood sugar levels, sugar, exercise, stress management, and other medical conditions.

You can work with your Doctor to find a healthy intake of carbs that gets you the necessary nutrients that your body needs. You could combine it with intermittent fasting, exercise and stress modification behavior, and so forth.

Learning these principles will help you to take the best from each area and understand how it fits you because there is no one-size-fits-all. We must start understanding what the modern world has changed in our food supply,  and what it has done to us so that we can adapt and try things that will work for us.

Challenges of a Paleo Diet

Eliminating all grains, dairy, processed foods, sugar, and more will likely lead to weight loss, but it may be a challenging plan to follow long-term due to dietary limitations and restrictions.

Some people find it hard to stick with it for a long time. Popular foods like birthday cake, pizza, or even a peanut butter sandwich weren’t available back then.. You may find yourself saying “no thanks” a lot when you’re visiting friends. And some ‘healthy’ foods, like whole grains, are off-limits.

However, there are ways you can make aspects of this diet part of your daily life. For instance, you can try to eat protein and a little fat at every meal or snack. You can also include more colorful veggies and fruits and limit the number of ready-made foods and snacks you eat.

Using the principles of a paleo diet as the starting point for a healthy eating plan makes sense to me.. Sure you can add beans, lentils, nuts, whole grains, low-fat or nonfat dairy, or other calcium sources such as dark leafy greens, tofu, and oat or almond milk, but always be mindful of what is ‘new’ in your diet and what is old.  Carefully choose lean protein sources, focusing on quality over quantity.

Some resources for finding that balance are available at ChooseMyPlate.gov, the DASH (dietary approaches to stop hypertension) eating plan, or by talking to a registered dietitian. Fad diets go in and out of style. Always check with a qualified nutrition professional before making big changes to your eating plan.