What is the Paleo diet?
It involves eating like our ancestors did. The Paleo diet involves eating naturally, eating grass-fed meats, wholefoods, fruit and vegetables. It was first promoted by Dr Walter L Voegtlin, a gastroenterologist. Dr Voegtlin’s book, The Stone Age diet, was published in 1975. There are many different Paleo approaches, their core principles are similar, but they vary in their restriction level. Other terms for the Paleo diet include hunter gatherer diet, caveman diet, Paleolithic diet.

Why follow the Paleo diet?                                                                                                  Advocates state that it promotes a natural way of eating with low sugar and salt levels and no processed or refined foods. A lot of followers of the Paleo diet believe that our digestive systems have changed very little since pre-agricultural or Paleolithic times. Many foods that we eat today could not be eaten raw in Paleolithic times. Therefore, Paleo followers believe that the following foods can create strain on the gastrointestinal tract: legumes, refined sugar, processed foods, potatoes, cereal grains, dairy, salt, refined vegetable oils and root vegetables.

It must be remembered that diets in pre-agricultural times varied in different locations due to seasonality, climate etc. People in pre-agricultural times were also a lot more active, than they are in modern times. Energy expenditure levels would have been higher in Paleolithic times.

Criticisms of the Paleo diet
The Paleo diet ignores the benefits of eating beans/legumes which have a low glycaemic index which is useful for individuals with blood sugar problems. It also ignores the benefits of consuming starchy vegetables, a source of nutrient dense energy and wholegrains which add bulk to the diet and assist with bowel movements. The omission of dairy limits calcium intake in the diet. Those at risk of osteoporosis should speak to a dietitian before going on the Paleo diet. The Paleo diet could be difficult to maintain on a long-term basis due to omission of food groups i.e. dairy.

What is the evidence on the Paleo diet?                                                                                 Studies have found the Paleo diet to be associated with an increase in satiety. This is independent of the number of calories or composition of nutrients. Improvements in waist circumference, body weight, blood pressure and lipid profiles have been found. However, these studies were of a short duration and had a small number of participants involved.  Also, a study by Melburg found increased weight loss on the Paleo diet at six months compared to a healthy control diet, but there was no difference in weight loss between the two diets at two years.

Studies have found palatability and compliance issues with the Paleo diet. The cost of the Paleo diet was indicated to be 10% more expensive than a diet of similar nutritional value after modelling the cost of the Paleo diet. This would make it unsuitable for those on a low income.

More research is needed on the Paleo diet. Larger studies of a longer duration are required before conclusions can be made about the effectiveness of the Paleo diet.

References:
Fisher, R., 2019. What is the Paleo diet? [online] Available at: Accessed [12th August 2019].

Manheimer, E.W., van Zuuren, E.J., Fedorowicz, Z. & Pijl, H. 2015, Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis, The American Journal of Clinical Nutrition, vol. 102, no. 4, pp. 922-932.

Mellberg, C., Sandberg, S., Ryberg, M., Eriksson, M., Brage, S., Larsson, C., Olsson, T., Lindahl, B., Medicinska fakulteten, Umeå universitet, Medicin, Institutionen för folkhälsa och klinisk medicin, Samhällsvetenskapliga fakulteten, Statistik, Handelshögskolan vid Umeå universitet, Institutionen för kostvetenskap & Yrkes- och miljömedicin 2014. Long-term effects of a Palaeolithic-type diet in obese postmenopausal women: a 2-year randomized trial, European journal of clinical nutrition, vol. 68, no. 3, pp. 350-357.

Pitt, C.E., 2016. Cutting through the Paleo hype: The evidence for the Palaeolithic diet. Australian family physician, 45(1/2), p.35.