What Are the Benefits and Risks of the Paleo Diet?

The paleo diet is the ultimate throwback diet: It promotes a return to eating as our ancestors did in the Stone Age. “This regimen is based on the idea that our bodies do best when fueled by foods that existed in the Paleolithic era, before agriculture came along 10,000 or so years ago,” says Mark Hyman, MD, author of Food: What the Heck Should I Eat? and the director of the Cleveland Clinic’s Center for Functional Medicine.

That means no sugar, grain, dairy, legumes, or beans on the paleo diet. No highly processed cookies or cakes. And no foods with added hormones or artificial ingredients. As for what’s on the paleo menu, think meat, fish, vegetables, and limited amounts of fruit, nuts, and seeds. “That’s about it,” Dr. Hyman says. It may not seem like much, but what you’re left with are nutrient-packed foods, many of which are excellent sources of fiber, which helps you feel satisfied and full.

Should you embrace the caveman way? Here’s what to know — including benefits and risks to be aware of, whom the diet is good for, and who should consult a physician before jumping on the bandwagon.

This way of eating may sound extreme — you’re cutting out entire food groups, after all — but it can be a healthy alternative to the typical American diet, which is high in grain-based, sugary foods loaded with highly processed fats and oils, Hyman says.

“Eliminating carbohydrates and processed foods may not be a bad idea — especially in the case of processed carbs — and may result in weight loss, since the bulk of the American diet comes from carbs,” says Adrienne Youdim, MD, an associate clinical professor of medicine at the University of California at Los Angeles David Geffen School of Medicine.

When you cut out processed foods and their empty calories — things like cookies, potato chips, butter, sweets, and sugary drinks — you’ll lose weight (as long as you have weight to lose).

But the benefits may extend beyond your waistline. One review suggests that, when compared with other diets, the paleo approach led to small improvements in blood pressure in people with signs of metabolic syndrome, fasting blood sugar, and triglycerides, which are fats found in the blood that can increase your risk of stroke, heart attack, and death. (1,2)

While cutting out whole food groups can certainly help your weight loss efforts (take, for example, the popularity of the all-meat carnivore diet, which most dietitians don’t recommend), you may run the risk of missing out on key nutrients. For instance, some experts caution against the paleo diet because eliminating dairy can leave you with lower levels of calcium and vitamin D. Over time, this could put you at risk of developing osteoporosis, bone fractures, or rickets. (3)

Many also worry because the diet is often interpreted as meat-centric. “Some use the paleo philosophy as an excuse to eat too much meat and too few plant-based foods,” Hyman says. If you’re not careful about the types of protein you eat, the diet can put you at increased risk of developing cardiovascular disease, Dr. Youdim says. Red meat, for instance, is high in saturated fats, which can raise blood cholesterol levels and increase the risk of heart disease. (4)

People who’ve had trouble following diets that require them to count calories or macronutrients may find this way of eating helpful. With the paleo diet, there are foods you can eat and foods you can’t eat, plain and simple. That doesn’t mean sticking to the diet is easy — in fact, many find it tough to follow, Youdim says — but it requires diligent food prep rather than calculating and journaling.

Hyman says there’s emerging research that the paleo diet (or the ketogenic diet, which is a more aggressive low-carb, high-fat diet) may help manage type 2 diabetes. One study found that people with type 2 diabetes who followed a paleo diet for two weeks saw improvements to their blood sugar, lipid profiles, and insulin sensitivity compared with those who stuck to a more conventional diet filled with salt, dairy, whole grains, and legumes. (5) Another study found that within 12 weeks, a paleo diet helped people with type 2 diabetes reduce their body fat, increase insulin sensitivity, and improve blood sugar control, among other benefits. In the same randomized controlled trial, those participants who did paleo and exercised also improved their heart health and boosted their lean muscle mass. (6) People with type 2 diabetes are two times as likely to die of heart disease as those people without the condition. (7)

Nevertheless, it’s important to note that both of these studies were small, with only 24 and 32 participants, respectively, so more research will be needed to confirm the results.

Even though some research suggests the paleo diet can help people with type 2 diabetes, they should consult a doctor first. Any drastic reduction in carb intake is worrisome for this group, especially for those who are on insulin; your blood sugar levels may plummet if you don’t make changes to your medications first, Youdim says.

Furthermore, while you might find claims online about the paleo diet helping treat autoimmune conditions, more research is needed before knowing what role, if any, this diet may play a role in treating ailments such as multiple sclerosis (MS), inflammatory bowel disease (IBD), and celiac disease, says Everyday Health staff dietitian Kelly Kennedy, RD, CDE.

Given the concerns over inadequate calcium and vitamin D, those who are at risk of osteoporosis (such as thin women over age 50) should proceed with caution and work with a doctor to make sure they’re maintaining appropriate levels of these nutrients. (8,9)

Finally, people with chronic health conditions such as heart disease or kidney disease should also consult a doctor first, says Erin Dolinski, RD, a clinical dietitian specialist in Royal Oak, Michigan. “With certain kidney diseases, an excessive intake of protein could actually strain your kidneys, reducing function and potentially leading to failure,” she says.