Paleo diet (also called the Caveman or Stone-Age diet) is based on the eating patterns of our Palaeolithic ancestors from roughly 2.5 million to 10,000 years ago. It focuses on foods that could be hunted, fished or gathered — mainly lean meat, fish, eggs, vegetables, fruits, nuts and seeds — while excluding grains, legumes, dairy and processed foods.
Why the Paleo Diet Became Popular
Modern Western diets are often high in calories, refined carbohydrates, added sugars and ultra-processed foods. These patterns have been linked to rising rates of obesity, type 2 diabetes, heart disease and other chronic conditions. The Paleo approach aims to return to a way of eating that is closer to what human genes evolved with.
What You Can and Cannot Eat
| Allowed | Not Allowed |
|---|---|
| Lean red meat, game meats, organ meats Poultry, fish and seafood Eggs Leafy and cruciferous vegetables, root vegetables, mushrooms Fruits Nuts (except peanuts) and seeds Raw honey (in moderation) | Grains (wheat, rice, oats, corn, barley, etc.) Beans and legumes (including soy) Dairy products Refined sugar and most processed foods Salt and refined fats Processed and fatty meats Soda and fruit juices |
Potential Benefits
Several studies have examined the short-term effects of a Paleo-style diet:
- Improved glucose tolerance compared with a Mediterranean-style diet in people with ischaemic heart disease
- Greater reduction in waist circumference
- Lower plasma lipids and blood pressure in some trials
- Weight loss and improvements in certain metabolic markers
The emphasis on whole foods, vegetables, fruits, nuts and lean protein, while avoiding refined sugars and ultra-processed items, is likely responsible for many of these positive changes. However, most studies have been short-term and relatively small, so long-term evidence remains limited.
Possible Side Effects and Drawbacks
When people first switch from a high-carbohydrate diet to a lower-carbohydrate Paleo pattern, they may experience temporary side effects such as:
- Headache and fatigue
- Lack of energy or dizziness
- Nausea or body aches
- Cold sweats
- Constipation or diarrhoea
These symptoms often improve within a few days to a couple of weeks as the body adapts.
Other potential disadvantages include:
- Lower calcium intake due to the exclusion of dairy
- Difficulty for vegetarians because beans and legumes are restricted
- Possible impact on gut health from reduced intake of grain-based fibre
Who Might Consider the Paleo Diet?
The Paleo diet is often tried by people aiming for weight loss, better blood sugar control or a generally less-processed way of eating. It tends to appeal to athletes and younger adults. However, it is not automatically suitable for everyone — especially those who rely on dairy for calcium, prefer plant-based protein sources, or need higher carbohydrate intake for performance.
References
- Cambeses-Franco C, et al. Is the Paleo diet safe for health and the environment? Sci Total Environ. 2021.
- Turner BL, Thompson AL. Beyond the Paleolithic prescription. Nutr Rev. 2013.
- Stanton R. Popular diets and over-the-counter dietary aids. In: Managing and Preventing Obesity. 2014.
- Patel S, Suleria HA. Ethnic and paleolithic diet: Where do they stand in inflammation alleviation? J Ethn Foods. 2017.
- Tarantino G, et al. Should patients with metabolic syndrome-related NAFLD be on the hunter-gatherer (Paleo) diet? J Gastrointestin Liver Dis. 2015.
- Cordain L. The Paleo Diet Revised. John Wiley & Sons; 2012.
- Lindeberg S, et al. A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet. Diabetologia. 2007.
- Boers I, et al. Favourable effects of consuming a Palaeolithic-type diet on characteristics of the metabolic syndrome. Lipids Health Dis. 2014.
- Andrikopoulos S. The Paleo diet and diabetes. Med J Aust. 2016.
- Zopf Y, et al. Dietary effects on Microbiota – new trends with gluten-free or Paleo diet. Med Sci. 2018.
- Usman M, Davidson J. Paleo Diet – Side Effects. 2015.