The Cooper Institute

Founded in 1970 by the "Father of Aerobics"
Kenneth H. Cooper MD, MPH


Should You Eat Like a Caveman? The Paleo Diet

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Tuesday, Jan 02, 2018

Should You Eat Like a Caveman? The Paleo Diet

No one would argue that most Americans need to improve their eating habits and increase their levels of physical activity. Rates of obesity and type 2 diabetes are at an all-time high among adults and children, while annual health care costs are approaching $3 trillion. These and other factors provide a rich and fertile environment for dozens of ‘miraculous’ and ‘revolutionary’ dietary approaches that are promoted every time we turn around. An example is The Paleo Diet; also known as ‘The Caveman Diet.’ The basic premise of The Paleo Diet is that we should only eat the foods that were available to our Paleolithic ancestors approximately 10,000 years ago. Since this era precedes the agricultural revolution, many foods (and some entire food groups!) are restricted.  Foods that are emphasized in The Paleo Diet include things that could be hunted/fished/gathered during the Paleolithic Era. These include meat, fish, eggs, vegetables, fruit, tubers (roots), nuts, and seeds. The only fluids allowed are water, coconut water and organic green tea.  Conversely, grains, legumes (beans, peas, and peanuts), dairy products, salt, refined sugars, and flour are not allowed. Proponents also suggest that since our Paleolithic ancestors were getting plenty of physical activity each day by hunting and gathering, then we should too. OK, I can buy that last part!                                                                                                

The web site for the author of The Paleo Diet claims that it is ‘the world’s healthiest diet; based upon the fundamental concept that the optimal diet is the one to which we are genetically adapted.’ Paleo Diet promoters claim that much of today’s obesity epidemic and related health problems are the result of consuming grains, dairy, and the other restricted foods mentioned above. Proponents further claim that grains, legumes, and dairy promote inflammation at the cellular level and promote disease. The notion that these foods promote disease is contrary to many published studies which have used the DASH (Dietary Approaches to Stopping Hypertension) eating plan. Whole grains, legumes, and low-fat dairy are among the cornerstones of DASH; which has been shown time and time again to reduce resting blood pressure and LDL cholesterol levels, as well as exert a favorable impact on blood insulin levels in both men and women! 

Some of the more vigorous proponents of The Paleo Diet claim that our ancestors seldom died from cardiovascular disease (CVD) or cancer; therefore we should eat just like our ancestors did. Not so fast! The average life expectancy during the Paleolithic Age was approximately 30-35 years. Starvation, exposure to the elements, infectious disease, and injury are thought to be the main contributors to this short average lifespan.  Therefore, relatively few people likely lived long enough to develop CVD or cancer during that time. Additionally, since only bones and bone fragments remain from our ancestors,  forensic scientists tell us that it is very difficult to determine how common (or uncommon) CVD, cancer, and other chronic health conditions were during that time!  

Are There any ‘Pros’ to The Paleo Diet?

Sure! Any diet that promotes plant-based foods, limits simple sugars and sodium, while encouraging physical activity has some strong positive aspects to it. Replacing sugary drinks with water and green tea is a great way to cut back on empty calories, and tea contains a wealth of antioxidants. Paleolithic man was very likely exceeding the current public health guidelines for physical activity (accumulate 10,000 steps per day), and we would do well to mimic our ancestors in this regard!

Are There any ‘Cons’ to The Paleo Diet?

Yes! While the diet may lead to short-term weight loss, it’s only because so many foods are restricted. When you eliminate two entire food groups (grains and dairy) as well as legumes, you’re not likely to consume as many calories as you did previously. As is the case for most popular diets, there are no published studies showing effective long-term weight loss with this approach. There are also no published studies showing that the Paleo approach decreases the risk of developing diabetes, CVD, or cancer. There is no evidence that whole grains, legumes, and low-fat dairy promote disease; in fact there are countless studies which show the opposite effect (DASH Eating Plan, Mediterranean Diet, etc).  The Paleo Diet is low in calcium and vitamin D and is high in meat. Vitamin D deficiency is a global epidemic, and the American Cancer Society has been urging Americans to decrease their intake of meat (red meat in particular) for more than a decade in order to decrease risk of developing several types of cancer.  

So now back to the original question. Should you eat like a caveman? Yes, but only if you limit red meat intake and add some whole grains, legumes, and low-fat dairy! If you have celiac disease or gluten intolerance (most people don’t), then you should definitely avoid gluten-containing grains such as wheat and rye. If you are lactose intolerant (most people aren’t), then try lactose-free dairy foods or soy products that have been fortified with calcium and vitamin D. To find a sound eating plan for your age, gender, and physical activity level, The Cooper Institute suggests that you go to or make an appointment with a Registered Dietitian. It always helps to remember that hip and trendy diets are typically not supported by much scientific evidence. Variety, moderation, and balance are the keys to a healthful diet.


Appel, L. J., et al.  A clinical trial of the effects of dietary patterns on blood pressure. DASH Collaborative Research Group. (1997). New England Journal of Medicine,  336:1117-1124.
Vollmer, W. M., et al.  Effects of diet and sodium intake on blood pressure: subgroup analysis of the DASH Sodium Trial. (2001). Annals of Internal Medicine, 135:1019-1028.
Holick, M. F. Vitamin D deficiency. (2007). New England Journal of Medicine, 357:266-281.
American Cancer Society guidelines on nutrition and physical activity for cancer prevention: reducing the risk of cancer with healthy food choices and physical activity. 2017 revision,

Note: The Cooper Institute has recently published a state of the art textbook titled Principles of Health and Fitness for Fitness Professionals. This book is an absolute must for fitness leaders, and is a great resource for anyone who is seeking to earn a nationally accredited personal trainer certification! Click on the links above to learn more.