A beginner's guide to the paleo diet, including how to do it and what to eat

• The paleo diet is based on what ancient hunter and gatherers would have eaten.
• Paleo diet foods include lean meats, fruits, vegetables, seeds, and nuts.
• The paleo diet may help you lose weight, but long-term effects are still being researched.

Although we're basically more advanced as a society now than ever before, some people believe that reverting back to certain ways of our ancient ancestors can result in healthier lives. Enter: The Paleo diet.

The Paleo diet is a modern diet that's supposed to be based on the way our ancient human ancestors ate during the Paleolithic Era, also known as the Old Stone Age, which began over 2 million years ago. These early humans were hunter-gatherers, eating what they could find and hunt in their surroundings.

So, the Paleo diet, in a way, is supposed to emulate eating like certain cavemen - and women - may have eaten. But whether, or not, that will actually help you lead a healthier life is up for debate. Here's what you need to know about the Paleo diet.

History of the Paleo diet

Gastroenterologist Walter Voegtlin introduced the Paleo diet in the 1970s as a way for humans to eat better. He believed that modern humans could learn how to eat healthier by following suit of our Paleolithic ancestors - hence the name Paleo diet.

But it wasn't until the early 2000s when the diet really took off in popularity, largely thanks to Loren Cordain and his book The Paleo Diet: Lose Weight and Get Healthy by Eating the Foods You Were Designed to Eat. In his book, Cordain lays out the guidelines of the paleo diet, as we know it today.

The Paleo diet cuts out processed and farm-based foods

Mainly, the focus is on nutrient-rich plants and protein-rich lean meats - and, of course, no processed foods, something that certainly wasn't around back then.

According to Mayo Clinic, the main staples of the diet are:

• Fruits and vegetables
• Seeds and nuts (excluding peanuts)
• Lean meat (whether it's chicken, pork, or beef)
• Fish
• Healthy oils derived from fruits and nuts

As for what to avoid, processed foods like potato chips and candy bars are an obvious no-no. But anything related to agriculture is also off-limits since the Paleolithic Era was before the time humans invented farming, 10,000 to 12,000 years ago. That means grains and dairy are out.

The diet also limits starchy foods like tubers - such as potatoes and jicama - and legumes like lentils, beans, and peanuts.

Unlike some diets, the paleo diet doesn't require you to follow a specific daily caloric intake. But it's likely that you'll consume fewer calories if you're sticking to it, since you're cutting out so many high-calorie foods, whether it's processed junk food, pizza and other fast foods, or high-sugar foods and drinks.

Watch out for certain vitamin and mineral deficiencies

When you're cutting out entire food groups from your diet - like grains and dairy - you have to consider the fact that you'll be missing out on the nutrients and health benefits of those food groups.

"There are certain things like brown rice or whole grains that are great for your diet - they help lower cholesterol and give you increased fiber - so you may want to just take a closer look and see whether or not it's really worth giving that up," says Leah Kaufman, MS, CDE, and RD at NYU Langone Health's Weight Management Program.

Kaufman also urges people to be careful not to become calcium deficient when giving up dairy. Eating chia seeds, almonds, and sardines are all good sources of calcium within the paleo diet. But Kaufman says if you are deficient, the best way to get sufficient calcium can be through a supplement.

To be safe, you may want to meet with a registered dietitian who can help you plan your paleo diet to make sure that you're meeting your nutrition needs.

If you're interested in going paleo but are worried about the risks and restrictions that may come along with cutting out certain food groups, you can try out a modified paleo diet, where the diet serves as a guideline for eating but isn't followed so strictly. For example, you can include some whole grains or legumes if you want more flexibility and added nutrition.

Research can't confirm if the Paleo diet is effective long-term

The Paleo diet may be effective for people who want to lose weight, as you will replace any processed foods - which are linked with weight gain - with whole and minimally processed foods like fiber- and water-rich vegetables.

However, there are no studies investigating whether, or not, the Paleo diet can help you lose weight and keep it off long-term. Nor are there long-term studies to suggest whether this diet can lower the risk of common health problems like heart disease.

The studies that do exist, suggest that the diet shows promise over short periods of time.

For example, a 2015 study published in The American Journal of Clinical Nutrition found that the paleo diet resulted in short-term improvement in metabolic syndrome - conditions that increase the risk of heart disease, stroke, and type 2 diabetes - when compared with a control group.

Other small-scale, older studies such as one published in 2008 in the European Journal of Clinical Nutrition found that the paleo diet can reduce BMI, weight, and waist circumference over a period of three weeks.

Most of these studies have been done with small sample groups, so research is still needed on larger groups for longer periods of time - as well as with comparison diets - to better understand the effects of the Paleo diet.

Insider's takeaway

The paleo diet is loosely based on how ancient hunters and gathers used to eat. It centers on whole, unprocessed foods like lean meats, vegetables, and fruits. Research on its benefits are still emerging, but it may help you lose weight.