- Recent evidence supports the paleo diet as a more effective way to lose weight quickly compared to a balanced diet but may not offer the range of nutrients needed to support a healthy diet.
The paleo or caveman diet has a controversial premise in that it supports consumption of lean meat, seafood, vegetables, fruits, eggs, seeds, herbs and spices but certainly not grains or corn, potatoes, legumes such as peas and beans, milk or dairy products. It has become popular with those looking at a lifestyle followed by early peoples or hominids nearly 10,000 years ago before the advent of processing or introduction of an agrarian economy. [By the way, the Paleolithic era covers a time period from 2.6 million years to the start of the formation of city states]. Our ancestors all those years ago hunted and fished for their food and they gathered it too which explains why certain foods we’ve mentioned are eaten are included whilst others are not.
The excluded foods are important to note because they include all processed foods and those that contain refined sugar as well as those with added salt. It is perhaps the absence of refined and processed foods which has appealed to all those who believe the Paleo diet is a better bet. The advocates of the diet reckon it is for the long-term. It is a healthy eating plan and anecdotal evidence suggests it can help people lose weight. Given the types of food being eaten and excluded it probably benefits those looking to reduce their risk of cardiovascular disease, cancers, diabetes and improve their overall well being.
Boundaries Of The Paleo Diet
From what can be perceived about the boundaries of the diet, various dieticians I’ve spoken to do not think there is an official version of the diet. It all depends on who is advocating it. Most dietiticians believe it is a low-carbohydrate and high protein diet which is in keeping with those such as the New Atkins Diet for example. There are variations on the levels of meat (protein) and carbohydrate intake and the range of variation probably means a strict Paleo diet is rarely followed.
Clinical Evidence For Nutrition Benefits From Following The Paleo Diet
Studies on the diet and its benefits are few and far between. Most are too small in size and number of subjects involved. Also, there are not enough comparisons made with other diets. For many years now there has been a desire for longer-term studies to show once and for all whether the paleo diet is as effective as many people claim it to be.
One review examined a four randomized controlled types as part of a meta-analysis (Mannheimer et al., 2015). The study found that there were short-term improvements in metabolic syndrome components compared to certain controlled diets. There was also some weight loss in the participants following the diet.
Generally speaking and in keeping modern views about diets, the adoption of a diet with modest levels of carbohydrate and fat and a reduction in salt probably would be healthy. The study did not come to any firm conclusions about the benefits or otherwise of an absence of dairy and wholegrain foods.
A recent study was conducted in Australia at the Edith Cowan University, Perth on the impact of the Paleo based diet on nutrition. Here, 39 healthy women were split between two types of diet (paleo versus balanced) and the researchers found that adopting the paleo diet led to a 4.3% reduction in their body weight and a 3.8% reduction in their waist circumference after just 4 weeks. The participants were randomised to follow either the paleo diet or one adopting the Australian Guide to Healthy Eating (AGHE) Diet. The AGHE diet recommends a balanced mix of fruit and vegetables, meat and dairy products, grains, legumes etc. The group adopting the balanced diet lost 1.6% in body weight and 2% in waist circumference over the same time period.
These results follow a similar pattern where a second study also showed a 3.5% reduction in body weight and 2% reduction in waist circumference after just three weeks. Another study on women who adopted the same paleo diet strategy also lost 5.3% body weight and 7.5% waist circumference after 5 weeks. The body of evidence is beginning to accumulate in favour of a paleo diet strategy where a reasonably rapid rate of weight loss is desired.
Overall Views On The Paleo Diet.
The reasons cited for the success of the paleo diet in such studies are due largely to a marked reduction in energy intake from carbohydrates and perhaps certain types of fat to some extent and an increase in the overall level of protein. The AGHE diet meant women consumed more carbohydrates but less saturated fat. The paleo diet recommends a high protein intake of between 20 and 35% of a person’s average energy intake whilst the AGHE Diet guidelines recommend 15 to 25%. The carbohydrate intake for a paleo diet is 35 to 45% (paleo) compared to 45 to 65% (AGHE) although paleo dieting is not considered a low-carb diet.
However, there are caveats to the paleo diet because whilst there is a sharper drop in weight loss, certain important nutrients such as sodium, calcium, iron and iodine, vitamins such as A and E, ascorbic acid (vitamin C), beta-carotene, folate are lower. There is a request from the researchers to understand the longer-term impact of the diet with such reduced levels of key nutrients especially calcium on bone health.
Processing Of Food With/Without The Paleo Diet.
It is also worth noting that meat sources and their quality might well have been very different and there would have been some basic elements of processing such as cooking. Most meat is produced from livestock living on soy rather than solely grass. Likewise, vegetables eaten nowadays are very different to those available in past times because of cultivation, crop development and even changes in soil and climate.
There were no differences in risk factors between the two groups of cardiovascular and metabolic risk factors and this too needs careful interpretation based on longer-term investigation. Many advocates of the paleo diet believe the adoption of this eating pattern reduces their chances of developing diseases such as cancer, heart, irritable bowel syndrome and type-2 diabetes. A larger study group would also help improve on the statistical analysis if conclusions are to be drawn on ameliorating these conditions.
The researchers state that “the reduction in body weight and mass found in this study cannot be attributed to the reduction in energy intake alone. This supports previous findings that lower carbohydrate diets are associated with greater losses of mass over a short term period.”
Paleo Cookbook Series
There is considerable interest in cooking within a Paleolithic based diet and there are some excellent cookbooks available which promote not only the concept but offer recipes and advice. One group of cookbooks that should be looked at is the Paleo Cookbook Series which places its recipes into eight categories from meat, chicken etc. to snacks and desserts. It covers the basics and should be investigated further if an interesting range of dishes is to be tried. I’d be pleased to know your opinion on the books as they look to offer useful advice and ideas and whether the diet actually proves to be of benefit.
It is worth noting that further research is to be published later in the Summer which should throw further light on the subject of the Paleolithic Diet.
General Views About The Paleo Diet
The BDA makes some very telling points about the Paleo Diet. From their perspective, the paleo diet encourages participants to reduce their processed food intake because it implies they will eat less fatty, less carbohydrate-dense food. The consequence is more fruit, vegetables, seeds and so on. It is very simple to follow and ‘doesn’t involve calorie counting’. The diet is flexible and so probably easier to follow and keep to. Given that dieting is often about discipline, anything that encourages being strict with eating habits is welcomed.
The issues with the diet are numerous. Records concerning the diet of our Stone Age ancestors do not exist save for what might be conjectured from examining archaeological evidence. The diet is largely based on guesswork but educated ones at least. Lost of meat is eaten which runs counter to good advice and the absence of wholegrains and dairy foods is also an issue because these two foods form part of the healthy eating message. There is no desire to cut out various foods if it means nutritional deficiency.
The BDA considers the diet to lack variety which makes sticking to it rather difficult. They consider following a variant which includes dairy, whole grains and legumes would be a better for you.
Genoni, A., et al., (2016) Cardiovascular, Metabolic Effects and Dietary Composition of Ad-Libitum Paleolithic vs. Australian Guide to Healthy Eating Diets: A 4-Week Randomised Trial. Nutrients 8(5) 314; doi:10.3390/nu8050314
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, 102(4), pp. 922–932. doi:10.3945/ajcn.115.113613 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4588744/
NHS (2018) https://www.nhs.uk/live-well/healthy-weight/top-diets-review/#paleo-diet accessed 1st May 2019.