This diet is also known as the hunter-gatherer or caveman diet. It is premised on theories about what humans ate historically, notably pre-agriculture. The logic of the theory has certainly encouraged participation and some very passionate proponents. In its purest form this can be a healthy diet. The benefits are that it focuses on micronutrients from plants, and healthy fats with a reduced ratio of animal protein. It also excludes all the bad stuff – processed food, fast food, polyunsaturated fats, refined carbohydrates, added sugars and chemical additives.
At a glance the Paleo diet seems quite similar to the high protein diet – the popular recipes are meat, meat and more meat. The Paleo diet is actually a high fat diet. Naturally sourced fats from animals and plants are considered the best source of energy and the key to weight loss. This includes saturated fats but specifically excludes any processed fats, especially polyunsaturated fats. The preferred fats are sourced from parts of the animal that have less protein, particularly offal. This includes the heart and liver for example.
This diet also includes non-starchy vegetables, fruits and nuts. These provide the micronutrients needed for good health while providing limited energy from carbohydrate. The idea is that the body will use fat for energy leading to weight loss.
This system is not without its critics, most notably from the ‘Nutrition establishment’, because it promotes saturated fats and excludes polyunsaturated fats, grains and legumes. The existing argument against saturated fats and for polyunsaturated fats really is falling apart and paleo proponents are happy to point that out.
The paleo diet excludes grains based on the argument that humans have not had time to adapt to them (in an evolutionary sense) and the period of modern agriculture is associated with the rise of disease. The critics argue that 10,000 years of agriculture is enough time for humans to adapt and that humans previously ate grains in their wild forms – which is why we chose to farm them.
My argument is that how we have come to grow and consume grain is the real problem, not grain itself. The rise of food industrialisation has seen the extensive hybridisation of grains combined with extensive processing. Grains, particularly wheat, are now consumed as highly refined, nutritionally void products. On this basis grain consumption has to be unhealthy, if not toxic.
Paleo enthusiasts also exclude legumes based on a theory that they contain ‘anti nutrients’ that inhibit the absorption of other nutrients. There are anti –nutrients (phytotoxins) in a variety of plants, not just legumes. For example oxalic acid in dark green leafy vegetables binds to calcium reducing its bioavailability. Anti-nutrients are found in such a wide variety of plants that they are virtually impossible to avoid. The human body has evolved to deal with them.
There are studies that can be used support the argument against legumes and grains – we know that there are always studies to support any argument – but historical evidence does not suggest that grains and legumes are intrinsically detrimental to your health, or that they are even poisonous as is suggested by Paleo bloggers. The Mediterraneans ate wheat and legumes for thousands of years and lived long, healthy lives.
The Paleo diet has become popular in only the last ten years or so. Therefore science-related arguments for it are not specific to it. It is a classic case of ‘pick your science to suit your argument’. Validation of this diet is really limited to anecdotal evidence, however there seems to be no shortage of that. The result of this is that arguments for this diet can be quite subjective and even emotive.
One of the ironies of the paleo diet is the promotion of supplements. The first question that comes to my mind is that if this is such a healthy diet why would you need supplements? You don’t. Supplements lack the efficacy to offer any value, especially if you are eating well. Paleo is a booming business of which supplements are a part, along with forums, books, restaurants and television programs. The rise of a ‘Paleo Industry’ has the potential to undermine this system as commercial interests takeover, just as the food industry has done to the ‘mainstream’ Western diet.
The bottom line: the great benefit of this diet is the elimination of processed and junk food, polyunsaturated fatty acids and sugar. It pays attention to plant food intake (with the exceptions of grains and legumes). The promotion of saturated fats is controversial but is in line with growing consensus. This diet is a lifestyle choice that is often associated with exercise. The overriding problem it is that it is difficult to understand, more difficult to implement, and requires serious commitment and discipline to follow. It is too easy to make it into a high protein diet if you don’t fully understand it (or don’t like offal).