Originally posted January 2018 / Updated February 2023

What Is the Paleo Diet?

The paleo diet, also called the Paleolithic, caveman, or hunter-gatherer diet, is based on what proponents claim were the foods available to prehistoric humans in the Old Stone Age or Paleolithic Era (roughly 2.5 million years ago to 10,000 B.C.). 

There is a lot of debate about the human diet during this period, as people struggled to find food at this time. And modern versions of almost every food dramatically differ from what it was during the Stone Age. 

Even common foods have changed dramatically over time through the cultivation of hybrids and selective breeding. And there has also been the development of many ultra-processed foods in the last 100 years.

How to Follow the Paleo Diet

The foundation of the paleo diet is an emphasis on lean proteins such as lean cuts of red meat, poultry, pork, wild fish, and shellfish. These foods should provide about half the daily calories. The diet also emphasizes eggs, organ meats, moderate amounts of fruit and non-starchy vegetables, and healthy fats from seeds, nuts, olive oil, and avocados.

Food to Avoid on the Paleo Diet

Foods to avoid are all dairy products, grains and products made with grain, beans, legumes, vegetable oils, high-omega-6 fatty acids such as corn, soy, safflower, sunflower oil, and iodized salts. 

Natural sweeteners such as maple syrup and honey are permitted, while other sweeteners are prohibited.

Paleo Diet Health Benefits

Clinical research on the paleo diet has focused on promoting weight loss, improving blood sugar control, and lowering cholesterol levels.

Because the diet is low in carbohydrates, it is similar to the ketogenic or keto diet. Learn more about the keto diet here. As such, initial weight loss can be significant due to water weight loss. People typically lose 4–6% of their total body weight within a 10-to-12-week period. 

There are only a few long-term studies on the paleo diet. One reason may be that it is very challenging to follow long-term because it is so restrictive. The paleo diet can create some nutritional deficiencies; mainly, it is a low-calcium diet.

References:

1. Eaton SB, Konner MJ, Cordain L. Diet-dependent acid load, paleolithic nutrition, and evolutionary health promotion. Am J Clin Nutr. 2010;91:295–7. 
2. Boers I, Muskiet FAJ, Berkelaar E, et al. Favourable effects of consuming a palaeolithic-type diet on characteristics of the metabolic syndrome: a randomized controlled pilot-study. Lipids Health Dis. 2014;13:160–72. 
3. Lindeberg S, Jönsson T, Granfeldt Y, et al. Palaeolithic diet improves glucose tolerance more than a mediterranean-like diet in individuals with ischaemic heart disease. Diabetologia. 2007;50:1795–807.
4. Jönsson T, Granfeldt Y, Ahrén B, et al. Beneficial effects of a paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study. Cardiovasc Diabetol. 2009;8:35–48. 
5. Manheimer EW, Van Zuuren EJ, Fedorowicz Z, Pijl H. Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis. Am J Clin Nutr. (2015) 102:922–32. 
6. Osterdahl M, Kocturk T, Koochek A, Wandell PE. Effects of a short-term intervention with a paleolithic diet in healthy volunteers. Eur J Clin Nutr. (2008) 62:682–5.