A nutritional program gaining popularity has a bone to pick with our current, highly processed and supersized dietary habits.

According to the Paleo (or Paleolithic) Diet, modern humans are not fully adapted to the nutrition and lifestyle changes that occurred after the Neolithic Revolution about 12,000 years ago.

Agricultural advances, mass production and increased food accessibility vastly altered what we eat. Because we are not genetically adapted for this, Paleo proponents suggest reverting to our ancestor’s diet in order to lead healthier lives devoid of chronic illness common in post-Industrial Revolution society.

The premise sounds simple: eat like a hunter-gatherer. This means a diet rich in organic, wild lean protein (fish, meat and seafood), fruits, vegetables and nuts. Excluded from the Paleo Diet are dairy products, grains, legumes as well as refined sugar, salt and alcohol. Strict Paleo dieters also limit their intake of high sugar fruits such as apples, grapes, bananas, cherries, mangoes, pineapples, pears and kiwi.

Along with dietary guidelines, exercise is recommended since hunter-gatherers were constantly on the move.

A team of nutrition and fitness professionals led by Dr. Loren Cordain helped popularize the diet. Cordain is an expert on Paleolithic Diets from the Department of Health and Exercise Science at Colorado State University.

Dr. Cordain’s website (thepaleodiet.com) outlines the Paleo Diet’s benefits. Cordain's report was published in Research Reports in Clinical Cardiology. One claim from the report is that hunter-gatherer populations are healthier than industrialized ones: they have lower blood pressure, body mass indexes and incidences of chronic degenerative diseases such as diabetes, cancer and cardiovascular complications.

The nutritional program, similar to the Atkins Diet with its heavy emphasis on meat, has become a top diet pick among celebrities such as Megan Fox and Uma Thurman and is increasingly prevalent within the intense, exercise-driven CrossFit community.

This is where Chicago registered dietitian and nutrition coach Amari Cheffer heard about the program.

“I am part of the CrossFit community and participated in a 30-day Paleo challenge with them,” said Cheffer. She has seen success with athletes and normal clients who go Paleo, as the plan allowed followers to decrease fat and increase muscle mass.

Despite this, many are split on the Paleo Diet’s validity.

Critics argue we do not know exactly what our Paleolithic ancestors ate and that a modern adaptation of the diet does not produce the same results. Similarly, skeptics say there is no proof in the Paleo pudding.

“The Paleo Brand is lacking formal research from independent sources like the National Institutes of Health,” said Beth Doerfler, an MS, RD and LDN at the Wellness Institute at Northwestern Memorial Hospital. However Doerfler said, “Aspects of the diet can be healthy as long as they are done correctly.”

Often, this is not the case. “Any diet with a sense of deprivation will have deficiencies,” said Ashley Pettit, certified nutrition coach, nutrition consultant and owner of the Ashley Pettit Living wellness company in Chicago.

The Paleo Diet eliminates several food groups and, as a result, lacks key nutrients like calcium, fiber and “good” (monounsaturated) fats. Even though the program is high in protein, the increased consumption of animal fat and eggs may cause an increase in LDL cholesterol.

Moreover, the diet’s limitations are difficult to sustain.

“Going off the diet can cause weight gain and can often lead to bingeing,” Pettit said. The Paleo Diet is not a quick fix for weight loss. “It is a decent way to cut cravings but it’s not realistic.”

Nonetheless, ancestral inspiration is onto something. Cheffer agrees lowering consumption of refined grains and sugars is a healthy goal. “We can all benefit from eating more quality protein, vegetables, fruits and nuts.”