Paleo Diet, as well as a long list of many others such as Keto, The Zone, Mediterranean, SPMF,... have claimed to be the ultimate diet for health and longevity. We have a huge tendency to try find the ultimate and healthiest diet to live longer. But is there really one?
In this post we'll review the main characteristics of Paleo diet to later discuss the science behind and how you could implement it in your lifestyle. During this 5min read, you'll get an overview of what Paleo Diet is and the evidence behind.
Where Does Paleo Diet Come From?
Paleo Diet (although there's more than one) tries to simulate the diet that our ancestral Homo Sapiens followed during the Paleolithic, back a couple millenials ago in history. Paleo Diet SIMULATES (and not COPIES).
Foods, wether you like it or not, are 99% manipulated by humans nowadays, and what we know as an apple nowadays is not the same as an apple in the Paleolithic. But where does the idea of Paleo Diet come from?
Research and attention on Paleo Diet began during the 1970s, but it became widely popular with the release of the book The Paleo Diet: Lose Weight and Get Healthy by Eating the Foods You Were Designed to Eat by Loren Cordain in 2002 (book).
When they started studying different ethnic groups around Africa and elsewhere, they found that these villages did not show a single case of cardiovascular events or anything alike.
Surprisingly, that happened independently of the diet they were following. Wether it was high-carb, low-carb... the results were very similar (study)
Many researchers and scientists consider the evolutionary traits of human history as degrading in terms of overall health and nutritional status.
Nutrition back in the days could be more benefitial to us than the actual diets and agriculture stated the beginning of another age with deteriorated health status and fitness.
Characteristics of Paleo Diet
Paleo Diet is based on a certain food selection, and we cannot classify it based on its macronutrients content (as we do with low-carbs, high-protein,...).
In a considerably short period of time (in 'evolutionary' terms), we have added a long list of new foods into our diets, either from the industrial or the agricultural revolution.
Macronutrient Content of Paleo Diet
Paleo Diet, different from others, is not strictly classified based on its macronutrient content and ratio. Because we have more than one Paleo diet depending on location, season,... we cannot talk about only one diet.
Kitava Island: diet based on 70% carbohydrates (yam, sweet potatoes,...) (study)
Inuits: diet based on fatty fishes, seals and very low on carb (study)
Paleo diets have been highly associated to 'Low-carb diets' only because of the absence of the main carbohydrates being present in our diets nowadays (pasta, rice, bread, cereals).
But that doesn't mean that there were no carbohydrates back in the Paleolithic. In fact, it is very possible to perform a 'High-carb Paleo Diet' including legumes, tubers, fruits and vegetables.
Food Selection of Paleo Diet
Paleo diet is based on: meat, fish, shellfish, fruits, vegetables, legume, tubers, eggs, and seeds.
These foods are just general ideas of what the Homo Sapiens ate back in the days, and there is a high variability between ethnic groups, time of the year, season, and location.
The diet of an ethnic group living in the centre of Africa is not the same as the one followed by another group living in North of Canada.
We cannot associate Paleo Diets to Low-carb diets, but the carbohydrates included in this list show a very high satiety index (study) and low glycemic index (study)
It is considerably easier to perform a low-carb diet being constrained by the rules of a Paleo diet than an actual Western diet.
Food Excluded from Paleo Diet
Another way to look at Paleo Diet is by the food we cannot eat, being this a better way to classify and perform the paleolithic diet. We cannot know exactly what our ancesstors ate on their daily basis, but we know for sure what they didn't eat.
- Ultraprocessed foods
- Dairy products
- Refined oils and trans-fats
This means that their snack was not a Donut, their breakfast was not milk with cereals, and their nutrition was based on their hunting and recollecting.
Science Behind Paleo Diet
Paleo diet, different from other 'Miracle diets' -based on no science at all- show some confident scientific evidence behind. In the next paragraphs we'll try to explain and discuss the strongest evidence built behind it.
- Improved body composition (study)
- Improve health parameters (study)
Cardiovascular Outcomes and Diabetes
Cardiovascular health is an emerging concern due to the high prevalence of cardiovacular events leading to severe health issues or even to death (study), getting 25% or all deaths taking place yearly.
Paleo Diet is effective at lowering cholesterol and improving the blood lipid profile (study), blood pressure and glucose tolerance, decreasing insulin secretion and increasing insulin sensitivity (study).
Paleo Diet may also other main causes of these diseases. When compared with a specific diet to treat Type 2 Diabetes, Paleo Diet was more effective at improving insulin sensitivity and glycemic control (study)(study)
This meta-analysis and systematic review concluded that Paleo Diet showed benefits over normal diets on cardiovascular outcomes.
Eight controlled trials were included in the systematic review, and the findings concluded that Paleo Diet could potentially benefit cardiovascular outcomes such as body weight, waist circumference, BMI and body fat percentage, among others.
Altough some of these benefits are enhanced by the application of a systemic calorie deficit due to the high satiety index of the diet, it seems like the distribution and election of foods has also a high importance, and benefits are also attributed to this fact.
Paleo diet is very satiating. If we look at the food list contained in Paleo Diet, we conclude that this diet is:
1) High in proteins. Protein is the most satiating macronutrient (study), above carbohydrates and fats.
2) Paleo Diet is abundant in vegetables and low-caloric foods. We'll have to eat way more to intake as many calories as with some other diets.
These two facts could already help us achieving a lower caloric intake without struggling with hunger.
In this study comparing Paleo Diets with a Mediterranian diet - considered a healthy and recommended diet - Paleo Diet was more satiating and calorie deficit was more likely to happen even when doing it Ad Libitum (based on feelings) (study).
Paleo Diet Improves the Gut Microbiota
The gut microbiota plays an important role in our health and immune system, and taking care of the health status of our microbes can help us achieving a higher quality of life.
Paleo diet is high in carbohydrates containing high amounts of fiber, such as fruits and vegetables. Fibers are non-degradable biomolecules being used by microorganisms to produce energy
The Paleo Diet could help achieving a more consistent microbiota related to our natural evolutionary traits (study).
- Paleo Diets are based on restricted foods similar to the nutritional habits back in the Paleolithic
- There are multiple diets depending on the ethnic group, latitude, location, season,...
- Paleo diets show improved cardiovascular markers and insulin sensitivity
- In terms of body composition, Paleo diets could be a great tool to induce an easier calorie deficit
Potential Adverse Effects of Paleo DIet
Everything has its pros and cons, even the greatest thing you can think of. Now we have seen the main benefits attributed to Paleo Diet, but are there adverse effects that we should consider?
Loss of Apettite
Although this can be a huge benefit when trying to cut off calories to induce a calorie deficit, it is a problem when we are in our 'bulking' season and trying to build some muscle mass.
Paleo Diet is very satiating, usually being high in proteins and vegetables.
If our daily caloric intake is around 3000 calories or above, eating such calories from this foods can get you into trouble.
Paleo Diet may be Restrictive
Paleo Diet gives you a narrower spectrum of foods to choose from, making adherence to the diet harder and more boring.
When deleting foods from our diets, we take the risk of showing some nutritional defficiencies and/or insufficiencies. From a start point, Paleo Diet is favoured to contain all sort of micronutrients to avoid any defficiencies, but let's go through the main ones:
+ Omega-3 and healthy fats: fatty fish, eggs, nuts, avocado.
+ Protein of quality: meats, white fish, eggs, insects.
+ Vitamin A: Liver, eggs, fatty fish, green veggies
+ Vitamin B: eggs, mushrooms, fruits, green vegetables, liver.
+ Vitamin C: orange, kiwi, blackcurrants, brocolli, peppers.
+ Vitamin D: eggs, fatty fish, sun exposure, liver.
+ Vitamin E: nuts and seeds
+ Vitamin K: green vegetables
+ Calcium: green vegetables, sardines.
+ Iodine: fish, shellfish.
+ Iron: meat, liver, beans, chickpeas, lentils
+ Magnesium: spinach, nuts
To avoid any deficiency, try to combine different foods to get all the micronutrients and vitamins.
Change in Bowel Habits
When we perform sudden changes in our nutritional habits, our system and microbiota needs some time to adapt to the new diet to start functioning properly.
This and the high content of fiber and other antinutrients present in foods such legumes can make you go to the bathroom more than usual (specially the first days).
Other Questions About Paleo Diet
Now we've gone through the main aspects of Paleo Diet. The food list, potential benefits and some facts to take into consideration.
But I know that there are still some doubts flying around your head.
Is Paleo Diet for me?
All the choices you make in relation to your diet should point towards higher adherence. If you like eating clean and avoiding ultra-processed foods because you are against them, Paleo Diet is for you.
If you crave sweets and donuts all the time and you can't live without them, maybe you'll have to do a longer transition before getting into Paleo Diet
Is Paleo Diet better for Weight Loss?
It's not better or worse. It's simply another tool you can use to induce a calorie deficit. We need the calorie deficit to lose weight. Without it, we are not going anywhere no matter the diet we are following.
Calorie deficit can be achieved in many ways. You could lose weight only eating ice cream as far as you are in calorie deficit (the results won't be as good).
We cannot say that Paleo Diet is better for weight loss when compared to other diets.
Due to the foods included, it could be easier to induce the calorie deficit than in other diets.
Does Paleo Diet improve my health?
Paleo Diet could help improving cardiovascular outcomes and other diseases such as diabetes and metabolic syndrome.
Paleo diets are based on natural foods, which make them, from a start point, way healthier and more benefitial for us than ultraprocessed foods.
But we still await more research on other fields to see how powerful this diet is and how far the idea of evolutionary nutrition can get.
Can I do a less restrictive Paleo Diet?
Of course you can. When we talk about nutrition, it's important to consider the long-term aspect. If we follow a restrictive diet for two weeks and go back to our normal 'shitty' diet, those two weeks were useless.
So if you enjoy once in a while some biscuits or cereals go for it.
Base your diet on the foods contained in the 'Paleo List', otherwise you won't be doing a Paleo Diet anymore. Be flexible and follow the rule 80/20
In this post you learned what Paleo Diet is and what foods to include to follow it.
Now you also know the main potential benefits of following a Paleo Diet.
Paleo Diet shows to improve cardiovascular outcomes, lipid profile, insulin sensitivity and glycemic control.