Is the Paleo Diet Worth the Hype? Uncovering the Truth Behind this Popular Trend

January 3, 2025

The trendy Paleo diet is built on the concept that eating like our hunter-gatherer Paleolithic-period ancestors can promote good health and weight control. The Paleo dieter's food choices are limited to what could be hunted, fished, or gathered in prehistoric times, focusing on naturally sourced lean meats, fish, nuts, vegetables, eggs, and fruits and eliminating dairy products, grains, highly processed foods, and refined sugar. While the diet does not require counting or cutting calories, it restricts high-calorie, low-nutrient processed foods, causing people on this diet to reduce their calorie intake, leading to short-term weight loss. But is it effective and safe in the long term?

A Remedy for an Unhealthy Diet Culture

The Paleo diet theory responds to today's typical Western diets, which are heavily processed, with high-fat dairy products, refined sugars, sodium, and refined oils particularly prevalent. In other words, we are moving in the opposite direction as our ancestors, consuming excessive, highly processed foods nearly devoid of crucial nutrients and engaging in little to no physical activity. A direction that promotes obesity and the risk of chronic diseases like heart disease, cancer, and type 2 diabetes. On the contrary, a devoted Paleo dieter eats no processed foods or added sugar. In addition to slashing high-calorie foods like pizza, burgers, and fries, they are loading up on foods with ample vitamins and minerals, like vegetables, fruits, nuts, and seeds.

The Paleo diet can also solve the imbalanced ratio between omega-6 and omega-3 fatty acids. Today's standard American diet has more than ten times more omega-6s than omega-3s; many refined seed and vegetable oils, found in most packaged snacks and fast foods, are high in omega-6s. Omega 3-rich foods include fish, flaxseeds, seaweed, walnuts, and olive oil. An even 1:1 ratio of omega-6s to omega-3s is optimal for warding off chronic inflammation that can lead to chronic disease. Our ancestors, no doubt, easily achieved a 1:1 ratio without refined oils and packaged snacks in their diets.

Does the Hunter-Gatherer Theory Hold Up?

It probably does not surprise you that studies comparing hunter-gatherer cultures with industrialized cultures find much higher obesity, blood pressure, insulin resistance, atherosclerosis (hardening of arteries), and lesser muscular strength and aerobic capacity in industrialized cultures. Therefore, the Paleo concept rationalizes that we should adopt similar eating habits. However, there are a few holes in the Paleo theory.

Firstly, life expectancy in pre-civilized societies rarely exceeded 25 years; modern-day chronic disease and obesity risk increases with age. Secondly, much of today's population leads a sedentary lifestyle compared to our caveman predecessors. Thirdly, the nutrient content of meat, milk, and produce has changed with the onset of mass food production. For example, most meat and dairy sources come from farm animals fed concentrated diets, leading to higher lipid content in our animal food supply. Research shows that wild animal meat contains less than 4% lipids, whereas domesticated meat contains between 25% and 30%. Most Americans do not hunt and fish for their meat year-round, and wild-caught meat at the grocery store can be costly. So, mimicking our ancestors' nutrient intake AND attaining the same fitness outcome would require an active lifestyle and ample access to fresh organic foods.

How Does the Paleo Diet Stack Up to Other Healthy Diets?

Many studies suggest that the Paleo diet positively affects body composition, insulin sensitivity, fasting blood glucose, lipids, inflammation, and blood pressure. However, most studies are short-term, often include physical activity changes, such as aerobic and resistance exercise, and typically result in weight loss. Therefore, whether any positive health effects are due to Paleo, physical activity changes, or weight loss is not clear. Removing processed foods and increasing fruits and vegetables likely improves body composition and disease markers. However, there is no evidence that the Paleo diet provides more long-term health and weight loss benefits than diets that have been more scrutinized by researchers, such as the Mediterranean or well-balanced plant-based diet.

What Are the Risks?

Paleo is one of many fad diets that omit whole grains, an essential component of a healthy diet. Grains (with dairy, fruits, and veggies) are a leading source of carbohydrates, the body's primary energy source. Whole grains are fiber-rich, which supports healthy digestion and satiety and reduces the risk of cancer, heart disease, and other chronic diseases. Whole grains are also a great source of vitamin E, selenium, zinc, copper, iron, and B vitamins.

A byproduct of the Paleo diet is the risk of consuming too few carbohydrates. A low-carb diet can bring about higher LDL cholesterol levels (the bad fat that increases the risk of heart disease) and ketosis, a status that incurs muscle loss, dehydration, and kidney strain.

Calcium is also of concern for those following a Paleo diet, as dairy remains its best source. Getting enough calcium decreases the risk of osteoporosis, rickets, and bone fractures and is associated with better weight outcomes. One short-term study revealed a 53% decrease in calcium intake from baseline in subjects following a Paleo diet for three weeks.

Lastly, it is essential to note that the Paleo diet emphasizes animal protein, which is often high in saturated fats, pointing to yet another risk factor of heart disease and type 2 diabetes. Although the recommended intake for fat under the Paleo guidelines is within the acceptable range of 35%, the reported intake of those following the diet is often much higher, around 40%, which would likely lead to fat being stored in the body, especially if the dieter is not burning the excess calories through an active lifestyle.

Is It Sustainable?

The Paleo diet is meant to be followed long-term, but most experts recommend against strictly following it for an extended period. Omitting whole grains, dairy, and legumes could lead to losses of vital nutrients and eventual harmful health outcomes. The diet's restrictive nature makes it hard to adhere to beyond a few weeks. Paleo-friendly foods may also be a budget strain for some, as fresh meats and produce are more expensive than frozen or canned foods.

Bottom Line

In the short term, Paleo is likely safe for most healthy people as a kick-start method to reduce and filter out empty calories. Pregnant women, growing children/teens, the elderly, or those with existing health issues such as cancer, heart disease, or kidney disease should avoid this diet. Including whole grains, calcium, and fiber, as well as adding legumes, would reduce disease risks and help maintain muscle while reducing fat storage. The diet requires ample access to fresh produce and naturally sourced meats, which could be a financial reach for some people. If weight loss is the goal, any energy-deficit diet will be effective, along with suitable lifestyle changes. A diet plan should never omit entire food groups or macronutrients; it should be well-balanced, sustainable for the long-term, nutrient-dense, and portion-controlled, with upper limits of plant-sourced protein, lean meats, and fish to sustain muscle mass as weight slowly drops.

Paleo Diet in a Nutshell.

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Author Stacee Raber Nault, MS Nutrition Education

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