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Why Critics Are Dead Wrong About the Paleo Diet

Author:

Chris Kresser

New York Times Bestselling Author

By Chris Kresser

New York Times Bestselling Author

Chris Kresser is the co-founder and CEO of the California Center for Functional Medicine, founder of The Kresser Institute, and author.

Photo by Shutterstock

Earlier in January, U.S. News & World Report issued its annual ranking of the best diets to follow for several different goals and health conditions. As you may have heard by now, the Paleo diet was ranked last (tied with the Dukan Diet) in the “Best Diet Overall” category of the 32 diets they reviewed. But just how reliable are these rankings? And how seriously should you take them?

To find out, let’s see what research and clinical experience really say about the Paleo diet according to the seven criteria used by U.S. News & World Report in their rankings.

#1: How easy it is to follow

Experts faulted the Paleo diet because “duplicating such a regimen in modern times would be difficult.” I’m not sure whether these experts were simply expressing their personal opinion, or whether they asked others to weigh in. Though U.S. News & World Report characterized the Paleo diet as “very lean, pure meats, and wild vegetables,” that is not an accurate portrayal.

Most Paleo experts advocate a wide range of foods, including meats (not exclusively lean), fish, nonstarchy vegetables, starchy plants like sweet potatoes, nuts and seeds, and even modest amounts of “non-Paleo” foods like full-fat dairy, potatoes, dark chocolate, and alcohol when they are well tolerated.

This explains why many of my patients are able to lose weight effortlessly with Paleo. In fact, many of them were successful with Paleo despite failing with numerous other diets in the past.

#2: Short-term effectiveness for weight loss

Setting aside the mountains of anecdotal evidence available to anyone who spends even a few minutes searching on Google, and the collective experience of physicians, other health care practitioners, personal trainers, and CrossFit gyms around the world successfully using Paleo as a weight loss tool, there are randomized, controlled trials—the gold-standard of scientific evidence—demonstrating that Paleo is effective for short-term weight loss.

What’s more, this weight loss is often achieved without restricting calories or limiting carbohydrates or fat, and while eating meals with a variety of nutritious and delicious foods.

#3: Long-term effectiveness for weight loss

Paleo is not a diet—it’s a holistic approach to eating (and living) in closer harmony with our evolutionary heritage. It’s more sustainable than most weight loss diets because it features a wide variety of real foods that most people enjoy eating.

Several lines of evidence suggest that Paleo is successful for long-term weight loss:

Paleo is more satiating per calorie than a Mediterranean diet and a low-fat diet. This means that people following Paleo are more likely to eat less without effort, which is the holy grail when it comes to weight loss.
Obesity and even being overweight are either rare or nonexistent in contemporary hunter-gatherer cultures following a Paleo diet.
Health care professionals and personal trainers have helped thousands of patients/clients lose weight with Paleo and keep it off.

#4: Nutritional completeness

Frankly, this one made me laugh out loud when I first read the rankings. The idea that the Slim Fast (#13 on the list) diet— based on highly processed and refined “nonfoods” like shakes and protein bars—is higher in nutritional completeness than the diet human beings evolved on over two million years is nothing short of preposterous.

Let’s examine the label of a Slim Fast shake:

As you can see, there is not a single real food to be found. Instead, we find a variety of highly processed and refined ingredients, including protein powder, sugar in various forms (sucrose, maltodextrin, dextrose), industrial seed oil (sunflower oil), thickeners (guar gum, carrageenan, and gum arabic), emulsifiers (soy lecithin), and artificial sweeteners (acesulfame potassium and aspartame).

The Paleo diet, on the other hand, consists primarily of meat, fish, vegetables, fruits, nuts and seeds, and starchy plants like sweet potatoes. According to this study on the nutrient density of common foods, these are the most concentrated food sources of the vitamins, minerals, and protein the body needs to function properly.

#5: Potential for preventing and managing type 2 diabetes

Type 2 diabetes is virtually nonexistent in contemporary hunter-gatherers that maintain a traditional Paleo diet and lifestyle. Likewise, studies have shown that Paleo is capable of managing and even reversing type 2 diabetes:

Aboriginal Australians lost weight and experienced improvements in metabolic markers after returning to their traditional Paleo diet (from a Western diet).
In a group of post-menopausal women, Paleo caused improvements in a wide range of metabolic markers, including body mass index (BMI), waist and hip circumference, blood pressure, fasting blood sugar, cholesterol, triglycerides, LDL/HDL cholesterol, and a variety of other inflammatory and lipid markers. It also decreased the accumulation of fat in the liver (non-alcoholic fatty liver syndrome).
Paleo led to reduction of weight, BMI, waist circumference, blood pressure, and lipid markers in a group of patients with type 2 diabetes.

All of these studies were published in peer-reviewed scientific journals, so it’s unclear why the editors, journalists, and experts involved in the U.S. News & World Report rankings missed them.

#6: Potential for preventing and managing heart disease

As with type 2 diabetes, heart attacks are rare or nonexistent in contemporary hunter-gatherers who follow their traditional ways. Some have argued that heart disease is rare in these populations only because the people don’t live long enough to acquire it.

This is a common misconception about the lifespans of hunter-gatherers. Recent studies show that contemporary hunter-gatherers that have even rudimentary access to emergency medical care have lifespans similar to our own.

Yet despite the fact that some people in these populations were living well into their 70s, heart attacks (along with other modern diseases like diabetes, autoimmune disease, allergies and asthma) were still either completely absent or extremely uncommon.

Furthermore, among the strongest risk factors for heart disease are high blood pressure, obesity, inflammation, type 2 diabetes, and dyslipidemia (high LDL and total cholesterol, high triglycerides, and low HDL cholesterol). As mentioned in the previous section, the Paleo diet has been shown to significantly reduce all of these markers in clinical trials.

#7: Safety

This was another conclusion that was particularly hard to swallow. How can the diet that humans evolved on for two million years be less safe than diets based on processed nonfoods with names most people without an advanced chemistry degree can’t pronounce, and that we’ve only been eating for less than 0.005 (five one-thousandths) percent of our evolutionary history? That doesn’t make any sense to me, and I doubt it makes sense to you, either.

As for the common objection that the Paleo diet is dangerous because it permits foods like red meat, eggs and saturated fat, the most recent research does not support a causal relationship between eating these foods and heart disease, cancer, or early death. For more information on this subject, see these articles:

So the next time you see a ranking of popular diets from a major news organization or a panel of “experts,” remember that there’s often much more to their conclusions than meets the eye.