The Paleo Diet is a way of eating that focuses around the inclusion and exclusion of certain foods based around their proposed likelihood to have existed in our ancestor’s diet. The underlying principle governing the Paleo diet is that by sticking to foods that our Palaeolithic ancestors would have eaten that this is more in tune with our own body’s genetics and therefore a healthier way to eat.
When we look at the foods that are allowed in the Paleo Diet it certainly encourages the consumption of whole, nutrient dense and avoids refined foods such as processed grains and sugar. The foods included in the Paleo diet include grass fed meat, fresh fruit and vegetables, eggs, fish, seafood, avocado and unrefined nut or plant oils. This seems like a solid foundation for any weight loss or healthy diet, being packed with protein, vitamins and minerals, fibre and healthy fats, providing our body with all its required essential nutrients.
Interestingly though, the paleo diet excludes some other foods we might find surprising as they would also be considered healthy by many people, being considered as whole foods and nutrient dense. For example legumes such as lentils, peas, chickpeas, beans, soybeans and peanuts are not allowed, there is also no dairy, no salt, potatoes or refined vegetable oils. It has to be said that the exclusion of some of these foods is based on some form of scientific reasoning, but that it is often taken out of context so that the negative impacts of these foods are overstated and the positive health effects ignored.
For example legumes are excluded from the diet because they contain compounds called phytates which can decrease the absorption of certain nutrients by binding to them, particularly iron and zinc. However this ignores that fact that several paleo friendly foods are higher in phytate than legumes. In reality the body is unlikely to be impacted by the amounts of phytates many of us would consume in the diet, so is not of any real legitimate concern.
This is only going to be a problem in a very heavily plant based diet (vegans for example) and this can easily be avoided by cooking foods, consuming vitamin C rich foods (which aids iron absorption), processing of grains and using vinegar as part of salad dressings, which all break down phytate and allows greater nutrient availability.
Since the original inception of the Paleo diet there are now different opinions on what Paleo actually ‘is’ and has a few slightly different ideologies you can now follow, some more inclusive of foods than others.
Unlike some other diets the focus isn’t around counting calories as such, it is based around providing the body with what Paleo advocates believe is best for human health and performance. Despite this lack of calorie counting, the Paleo diet has shown an ability to cause and maintain weight loss. However, much like other ‘clean’ diets that focus on whole foods and the removal of processed foods that are often calorie dense and easy to overconsume, these weight loss effects are still caused by an overall reduction in calorie intake.
The other main benefit of the Paleo diet is the focus placed on including meat in the diet, thus the typical Paleo advocate will be consuming a high protein diet. High protein diets are beneficial for recovery for those who take part in resistance training and also for those looking to lose body fat. Protein is the most filling macronutrient so this helps to control hunger even if calorie intake is restricted, which has obvious fat loss and weight management benefits. A high protein diet is also muscle sparing, especially when combined with exercise, which is important to maintain muscle mass which can be put at risk when under periods of caloric restriction.
The main criticisms of Paleo are related to its unfounded restriction of certain foods. The truth is that as we have evolved, so have our digestive systems. This means that we can now handle foods that historically our bodies couldn’t. It is also important to consider that our Palaeolithic ancestors’ access to food barely resembled what we see today. Even the meat and vegetables we eat today has changed massively through modern farming techniques, therefore eating strictly paleo as our ancestors may have, is in any real way impossible.
The Paleo Diet might also be detrimental for people with high training volumes and who are focused on performance. This is because the Paleo Diet indirectly encourages a lower carbohydrate diet and without sufficient carbohydrate there is likely to be long term reductions in muscle glycogen. Reductions in muscle glycogen, being an essential fuel source for high intensity, anaerobic exercise, has the potential to impair performance and recovery, so for those who train to maximise performance then inclusion of sufficient carbohydrates in the diet is a must.
There are also few issues from both a historical and geographical perspective. The Palaeolithic era lasted from approximately 2.6 million to 10,000 years ago and that equates to a lot of change in both food availability at certain time points and in different locations around the globe. This means that at different time points and locations, the diet of our Palaeolithic predecessors would have looked very different and based largely on opportunity and availability, not optimised for overall health and longevity.
In summary, the Paleo Diet is an effective strategy that can help to promote weight loss and general health. However, this is more to do with the inclusion of more nutrient dense whole foods and a high protein content than it is to do with the inclusion or exclusion of certain foods for what some might consider arbitrary reasons. This exclusion of certain foods can mean that for some people the diet becomes overly restrictive and difficult to adhere to, especially if people don’t understand the mechanisms behind how the Paleo Diet works.
Gibson et al., (2006) Improving the bioavailability of nutrients in plant foods at the household level. Proceedings of the Nutrition Society. 65:160-168.
Schlemmer et al., (2009) Phytate in foods and significance for humans: Food sources, intake, processing, bioavailability, protective role and analysis. Molecular Nutrition and Food Research. 53:S330-S375.
Siegenberg et al., (1991) Ascorbic acid prevents the dose dependent inhibitory effects of polyphenols and phytates on non-hemeiron absorption. American Journal of Clinical Nutrition. 53:537-541.
Manheimer et al., (2015) Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis. American Journal of Clinical Nutrition. 102:922-32.