Fitness Nutrition

The Paleolithic (Paleo) Diet

National Academy of Sports Medicine
National Academy of Sports Medicine
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By Brian Sutton MS, MA, CES, PES, NASM-CPT

The world of nutrition is full of controversy, both disagreements within the scientific community as well as discrepancies (often marketing driven) between consumer media reports.

Nowhere is this dissension more evident than in the discussion of dieting. A diet gaining popularity in the consumer market and subsequently studied in the scientific community is the Paleolithic (or Paleo) diet. Is this diet healthful or hype?

Let’s take a closer look and offer up the latest research on the Paleo diet. If you are a nutrition specialist, you can inform your clients on the potential merits and demerits of the diet.

What is the Paleo Diet?

The Paleo diet, also known as the Caveman diet, consists of eating uncultivated plants and wild animals in a similar fashion to what cavemen are presumed to have eaten thousands of years ago. It is a high-protein, high fiber, low fat diet. Why should we eat like a caveman? The premise is that genetically our bodies are programmed to eat like our stone aged ancestors (prior to modern agriculture).

The Paleo diet is based on foods that can be hunted, fished, and gathered such as meat, fish, fruits, honey, vegetables, eggs, berries and roots. If a food did not exist 10,000 years ago, chances are it is not an authentic Paleo food item.

However, a true Paleo diet is difficult to follow because most meats and plants are domesticated rather than wild. At best, most individuals can follow a modified version of the Paleo diet that’s gluten free and organic. Supporters of the diet also recommend eating grass-fed meats (versus corn fed) because they’re closer to the nutritional quality our ancestors would have experienced.

You won’t find certain foods on the Paleo diet such as legumes (peas, lentils, beans), dairy, grains, sugar, potatoes, and processed oils. In addition, you won’t find any drinks other than coconut milk, organic green tea, and of course, water.

There are many versions of the Paleo diet and some are stricter than others. Some versions of the plan allow for leniency regarding certain oils such as flaxseed and olive oils.

See a similar diet in the Whole30

Proposed Benefits of the Paleo Diet

According to the creator of the Paleo diet, Loren Cordain PhD, “It’s the key to speedy weight loss, effective weight control, and, above all, lifelong health. The Paleo Diet enlists the body’s own mechanisms, evolved over millions of years, to put the brakes on weight gain and the development of the chronic diseases of civilization.” (1).

According to Eaton at al., Paleolithic diets consist of more fiber (both soluble and insoluble), more micronutrients (vitamins and minerals), healthy carbohydrate sources (fruits and vegetables), and more animal protein sources. Combined with little sodium, sugar, and saturated fat intake, a Paleo diet deserves more investigative support (2).

A 2009 research study performed by Frasetto et al., concluded a short-term consumption of a Paleolithic diet can lower blood pressure and glucose tolerance, and improve blood-lipid profile (cholesterol) compared to the average American diet (3).

Similarly, a 2009 randomized 3-month crossover study performed on 13 diabetic patients demonstrated a Paleo diet can improve glycemic control and several cardiovascular risk factors for patients with Type 2 diabetes compared to a conventional diabetes diet (4).

READ MORE: Paleo Diet for Athletes

Potential Shortcomings of the Paleo Diet

Nutritional experts and the scientific community agree diets should consist of more fruits and vegetables, less sodium, sugar, saturated fat, and processed foods for optimal health. However, there is substantial evidence indicating the healthful effects of diets containing low-fat dairy, legumes, and whole grains (5-8), which the Paleo diet explicitly excludes.

According to a meta-analysis examining literature published from 2004-2009, there is moderate evidence of an inverse relationship between the intake of milk and dairy products and blood pressure. The research study concludes that dairy intake may improve blood pressure and the risk for hypertension (high blood pressure) (5).

In 2006 researchers investigated the relationship between consuming cereal grains and legumes on the prevention of coronary heart disease and stroke. Based on the evidence the researchers determined, “The intake of wholegrain foods clearly protects against heart disease and stroke…” (6).

Another systematic literature review performed in 2004 examined the relationships between cereal grains, legumes and diabetes. Based on the findings the researchers conclude, “…there is strong evidence to suggest that eating a variety of whole grain foods and legumes is beneficial in the prevention and management of diabetes.” (7).

Lastly, researchers at Cornell University examining the health benefits of whole grain phytochemicals states, “Increased consumption of whole grains has been associated with reduced risk of major chronic diseases including cardiovascular disease, type II diabetes, and some cancers.” (8).

Now What? Applying the Research

Clearly, health and nutrition experts agree a healthful diet should include more fruits and vegetables, fiber, and lean protein sources. However, many experts also agree whole grains, legumes, and low-fat dairy also provide health benefits.

If you choose to follow the Paleo diet, you may need to supplement your diet, especially if you’re a picky eater when it comes to fruits and vegetables. A multi-vitamin and separate calcium supplement can act as insurance to help ensure you’re consuming adequate nutrients.

Lastly, the more restricted the diet, the harder it is for individuals to adhere and often leads to higher dropout rates (9). If you’re planning on following the Paleo diet, choosing a Paleo plan that allows for some leniency may result in greater adherence and long-term success.

You can find more information and context by checking out the NASM blog: A Low Carb Diet for Athletes.


1. Cordain, L. The Paleo Diet Revised Edition; Lose Weight and Get Healthy by Eating the Foods You Were Designed to Eat. John Wiley & Sons Inc. 2002. 11.
2. Eaton SB, Eaton SB 3rd. Paleolithic vs. modern diets--selected pathophysiological implications. Eur J Nutr. 2000 Apr;39(2):67-70.
3. Frasetto, L. et al. Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet. Eur J Clin Nutr. 2009 Aug;63(8):947-55. Epub 2009 Feb 11.
4. Jönsson T et al. Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study. Cardiovasc Diabetol. 2009 Jul 16;8:35.
5. McGrane MM, et al. Dairy Consumption, Blood Pressure, and Risk of Hypertension: An Evidence-Based Review of Recent Literature. Curr Cardiovasc RiskRep. 2011 Aug 1;5(4):287-298.
6. Flight I, Clifton P. Cereal grains and legumes in the prevention of coronary heart disease and stroke: a review of the literature. Eur J Clin Nutr. 2006 Oct;60(10):1145-59. Epub 2006 May 3.
7. Venn BJ, Mann JI. Cereal grains, legumes and diabetes. Eur J Clin Nutr. 2004 Nov;58(11):1443-61.
8. Okarter N, Liu RH. Health benefits of whole grain phytochemicals. Crit Rev Food Sci Nutr. 2010 Mar;50(3):193-208.
9. Dansinger ML, Gleason JA, Griffith JL, Selker HP, Schaefer EJ. Comparison of Atkins, Ornish, Weight Watchers, and Zone diets for weight loss and heart disease risk reduction: a randomized trial. JAMA 2005;293(1):43–53.

The Author

National Academy of Sports Medicine

National Academy of Sports Medicine

Since 1987 the National Academy of Sports Medicine (NASM) has been the global leader in delivering evidence-based certifications and advanced specializations to health and fitness professionals. Our products and services are scientifically and clinically proven. They are revered and utilized by leading brands and programs around the world and have launched thousands of successful careers.


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