The Paleo diet may help people lose weight, but its long-term effects are unclear

Here's how to get started on a meal plan that emphasizes the foods that people at in prehistoric times

A paleo diet is based on foods humans might have eaten during the Paleolithic Era, which occurred 2.5 million to 10,000 years ago. People at that time were mostly hunters and gatherers.
Source/Image licensed from Ingram Image

For people who are looking to lose weight quickly, the Paleo diet – which is based on the food that people ate during the Paleolithic Era – may provide the short-term benefits they are looking for. But some scientists caution that its long-term effects are not well-studied. 

During the Paleolithic Era, which occurred 2.5 million to 10,000 years ago, humans were mostly hunters and gatherers. But this period predated farming, so their diets did not include grains, legumes or dairy products. 

The theory behind this diet, according to the Mayo Clinic, is that our bodies were not built for the modern diets that grew out of farming and that this may be why conditions like obesity, diabetes and heart disease have become prevalent today.

The modern Paleo diet focuses on fruits, vegetables, lean meats, fish, eggs, nuts and seeds. It eliminates grains (wheat and oats), beans, lentils, peanuts, milk, cheese, refined and added sugar, added salt, starchy vegetables (like corn, peas and white potatoes) and any highly processed foods, like chips or cookies.

Some people have found the diet is effective for weight loss, maintaining a healthy weight and reducing the risk of cardiovascular disease. The modern diet dates back to the 1970s, but it was popularized in 2002 with the publication of Loran Cordain's book, "The Paleo Diet."

If you're considering adopting the Paleo diet in the new year, here's what you should know. 

What are the benefits of the Paleo diet?

Small, short-term studies have suggested that the Paleo diet can help people manage weight, blood pressure, cholesterol and triglycerides, but there is little data on the long-term effects of the diet. Most studies only followed participants for a few weeks or months, and the definition of the diet tended to vary between them.

A 2007 study found that participants lost weight and slightly reduced their waist circumference and systolic blood pressure on the paleo diet. In a 2013 study, participants lost an average of 9.9 pounds and experienced a 3.1-inch reduction in waist circumference.

One of the few larger studies found the Paleo diet may lower the risk of heart disease and cardiovascular risk factors, mainly because it eliminates processed foods.

Another larger study study followed 70 post-menopausal women with obesity for two years. The participants were either randomly assigned to a Paleo diet or a Nordic diet. Though both groups experienced a significant decrease in fat mass and weight circumference at 6 and 24 months, the Paleo diet induced greater fat loss at 6 months, but not at 23 months. In addition, triglyceride reduction was more significant in the Paleo group.

Doctors say longer studies with larger participant pools are needed to better understand the long-term benefits and risks of the Paleo diet. 

Potential risks of a meat-heavy diet

One of the biggest concerns with the Paleo diet is the lack of whole grains, legumes and dairy products. These are good sources of fiber, protein and vitamins. Research that compared the Paleo and Mediterranean diets found that both reduced cardiovascular risk factors, but the Mediterranean diet was associated with less harmful side effects.

A 2020 study found the Paleo diet did not differ from other types of healthy diets in regard to blood sugar management for people with diabetes.

This type of eating pattern also might lead to nutritional deficiencies, particularly in calcium, vitamin D and B vitamins. One study noted that after following a Paleo diet for three weeks, study participants showed a 53% decrease in calcium intake.

Health experts also have expressed concerns about the high meat intake with this diet. A diet heavy on red meat has been associated with a higher risk of death, cardiovascular disease and diabetes.

There is still little research on the long-term adverse side effects of the Paleo diet, particularly among people with chronic diseases and the elderly. Research is also inconclusive regarding its long-term effect on athletic performance.

How to get started

For this type of diet, stock the kitchen with fruits, vegetables, nuts, seeds, eggs, lean meats, grass-fed animals or wild game, fish, and oils from fruits and nuts. 

Here are some sample meal combos from the Mayo Clinic, thepaleodiet.com and Healthline that can help people get started.

For breakfast:

• Broiled salmon and cantaloupe
• Crispy Pumpkin Spice Waffles
• Bacon, eggs and one piece of fruit

For lunch:

• Salad made with romaine, carrot, cucumber, tomatoes, avocado, walnuts and lemon juice dressing
• Pork Spring Roll Salad
• Chicken salad with olive oil and a handful of nuts

For dinner:

• Lean beef sirloin tip roast, steamed broccoli and a salad with mixed greens, tomatoes, avocado, onions, almonds and lemon juice dressing
• Sage-infused Mushroom burgers
• Ground beef stir-fry with vegetables and berries