About 2.5 million years ago, the earliest humans were chipping away at stones to make rudimentary tools (hence, the ‘Stone Age’), running away from mastodons and other prehistoric beasts, and eating whatever they could hunt and gather. And they must have been a healthy bunch!

At least, those who adhere to the Paleolithic (Paleo) diet, which seeks to emulate the nutritional habits of these early ancestors, seem to assume that Stone Age humans had the right idea when it came to food. “Proponents of the Paleo diet believe that if our ancestors did not eat it, neither should we,” says Kathy Mankofsky, a registered dietitian with Mercy Hospital Dietitian Services.

“Paleo diet advocates believe that modern humans are genetically adapted to a Paleolithic diet and not to the standard American diet,” Mankofsky adds. “They believe that our genes have not changed much since the Paleolithic times. They believe that the modern diet may lead to chronic diseases such as diabetes, obesity and heart disease.”

Although various websites, books and articles present slightly different takes on a proper Paleo diet, the basis is restriction of all grains, dairy, legumes, beans, sugar and salt, explains Rabia Rahman, instructor of nutrition and dietetics at Saint Louis University. Organic fruits and vegetables, wild-caught fish, grass-fed beef and cage-free poultry are emphasized.

The concept of eating more whole foods and fewer processed food products has been touted by physicians and dietitians for years. Yet in our culture of fast food and packaged meals, it’s still a challenge. “I have had a number of clients who have tried the Paleo diet, and for them, the most difficult part has been the avoidance of all processed foods,” says Rahman. “A lot of clients have told me that they thought they were eating relatively healthfully before trying the Paleo diet; and once they tried it, they were surprised by how much packaged and processed foods they actually consumed before.”

In addition to the increased task of preparing meals from scratch, some people find the exclusion of dairy and grains difficult to adhere to for long periods. Cost also can be a factor for those who find it difficult to afford more expensive organic and grass-fed foods.

“There are cookbooks available that provide some flexibility,” notes Valerie Jewell, an independent personal trainer. “Different authors have slightly different views of what is acceptable within the basic Paleo template. For instance, I use a cookbook that allows for some white rice and peeled potatoes.”

Jewell also notes that people who want to lose weight should include exercise, not just diet, in a healthier lifestyle. “Strength-training is key—not just cardio. People need to start by building up their strength in order to walk, bike, etc.”

Although a handful of small studies have indicated that the Paleo diet may help reduce the risk of heart disease and diabetes, the evidence is not overwhelming, Rahman notes. While she suggests we all reduce consumption of processed foods, she says that the Paleo diet is not for everyone, especially those with kidney disease or who are at risk for osteoporosis. “If you’re looking to improve your overall diet, the Mediterranean diet or DASH diet would be a better idea.”

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