September 2019

The Carnivore diet – Good or bad?

Of all the trends that go against conventional nutritional advice, the carnivore diet may seem like the most radical one yet. Excluding fruits, vegetables and carbohydrates goes against the grain of regular nutritional advice, but is it the way forward? We delve deeper into the science behind this meat-centric diet and if it can really deliver the health benefits suggested.

The carnivore diet is pretty self-explanatory. It is the consumption of animal products and the exclusion of any non-animal originating foods. Many people say that it is the style of eating that our ancestors would have adopted, but humans have never purely eaten meat, we were, and still are are omnivores and our diets consisted of fruit and vegetables as well as meat and animal products.

However, the carnivore diet is amassing followers and gaining popularity due to the positive results its followers are seeing. The most famous advocate of this diet is orthopaedic surgeon and lifelong drug-free athlete, Shawn Baker. Baker is in his 50s, in excellent shape and a physical marvel after setting two indoor rowing world records. He claims that by only eating animal products – mainly limiting himself to only rib-eye steaks – for over a year, he has avoided ill health and managed to massively improve his strength and muscle gain. He encourages anyone who is willing, to try and record their experience on the diet, although he has admitted that since starting this extreme lifestyle change, he has had no health checks or blood work done to measure his cholesterol, triglycerides and inflammation markers. Fortunately, other people have been wiser and had tests to ensure that they are healthy.

But before we discuss the health benefits, lets define exactly what you can eat.

Permitted Foods

This diet is restricted to animal foods only. Providing that your meal walked, crawled, flew or swam, they’re fair game. There are no other rules to follow and you simply eat when you’re hungry until you are full. Below are some examples of what you can eat.

  • Meat – Red meat, including steaks and burgers, are the main dietary constituents of many carnivore dieters’ meals. Contrary to what you may think is healthy, this diet advises that fattier cuts of meat are better as they contain more calories, and due to the exclusion of carbohydrates, you need to ensure you are getting your minimum calorie requirement as to keep your energy levels up.
  • Fish – Any kind of fish is allowed. However, like meat, fattier cuts such as salmon are best. Eggs Must be eaten as a whole. It is not allowed to only eat the egg whites or the yolk.
  • Dairy – As milk, cheese, yoghurt and butter is classed as animal products they are technically admissible. Nevertheless, due to many carnivore dieters transferring over from the ketogenic diet (which doesn’t allow sugars, such as lactose found in milk), these by-products are often excluded or at least limited. It is advised to try dairy foods one at a time to see how you feel – it may be that you feel better totally avoiding them.
  • Bone marrow – Bone broth is allowed.
  • Condiments – Salt and pepper are allowed and technically if condiments are sugar-free, there should be no harm in using them as part of this diet.
  • Supplements – No dietary supplements are allowed. Although dieters do report drinking coffee or taking caffeine supplements pre-workout for an energy boost (even though coffee isn’t an animal product). If you are concerned that you’re not getting all of the nutrients you need, a daily multivitamin would be a good idea.

Reported health benefits

1) Weight loss – Along with the ketogenic diet, restricting your carbohydrate intake will keep your blood sugar low at all times. This means that you won’t get insulin spikes and therefore will not store any incoming calories you take in as body fat. Also, due to the limitations on what you can eat, it makes it extremely hard to create a calorie surplus without an effort, especially as protein and fat are highly satiating nutrients.

2) Lower inflammation – Meat has been suggested to promote inflammation, however, conflicting studies may indicate that it has the opposite effect. A 2013 study published in the journal of Metabolism compared subjects who ate a high-fat, low-carb diet to those that followed a low-fat, high-carb diet (calories were restricted in both groups). The results showed that the high-fat eaters had lower markers of inflammation after 12 weeks. Although this study proves a high-fat diet isn’t necessarily bad, there are different types of fats which have different effects on health – for example salmon is rich in omega-3 which is known to have anti-inflammatory effects, whereas fat surrounding the outside of a steak is high in saturates and also LDL-cholesterol which can cause inflammation. So the high-fat, carnivore diet may not actually elicit the effects of this study.

3) Higher testosterone – Diets high in fat have been known to increase testosterone levels. This is because testosterone is a steroid hormone which consists of and interacts with fat molecules. Therefore, if you have a high fat diet, you have more fat in abundance to produce testosterone. A study in the American Journal of Clinical Nutrition found that men who had a high-fat and low-fibre diet, after 10 weeks, had higher testosterone levels (13% increase) than those who followed a low-fat, high-fibre diet.

Is it safe?

Risk of cancer – Red meat and cancer have been linked, with processed meat being identified as being just as harmful and likely to cause cancer as smoking. However, lean red meat is defined as being ‘probably carcinogenic’, meaning that it might contribute to the formation of cancers but there is no clear evidence or research to suggest that it does. However, from a nutritional point of view, red meat not only packs a punch with its high protein content, but it is also rich in iron, zinc and B12 – all essential nutrients which can help with a wide array of bodily functions from improving immunity to increasing red blood cell formation. The NHS recommends that you eat no more than 70g a day of red meat, something which would be hard to follow on a red meat-rich, carnivore diet. The NHS also advises avoiding the consumption of processed meats (due to its link with cancer), eliminating a large group of food you can actually eat, making the diet even more restrictive than it already is!

Gut biome – Your gut contains both good and bad bacteria which helps to digest your food and prevent disease, these bacteria rely on energy from carbohydrates ingested through the diet. So surely if you only eat a carbohydrate-restrictive diet, your bacteria won’t have the energy they need to function properly. However, some followers who are on the carnivore diet suggest that when they have been tested, they had low levels of dysbiotic flora (bad bacteria) and good numbers of the beneficial flora. Their theory is that the exclusion of carbohydrates (sugars) has starved sugar-hungry bad bacteria to death – but surely this would have happened to the good bacteria too? There is currently little evidence to support either side of the argument.

Nutrient deficiencies – As previously stated, red meat alone contains copious amounts of iron, zinc and protein, while seafood and dairy supply the vitamin D – all of which usually have to be added to plant-based diets. However, there are some nutrients you could be missing out on. For example, vitamin C. Vitamin C is required for the repair of tissue and the enzymatic production of certain neurotransmitters (which assist in bodily functions such as movement). It is also an antioxidant and is required for some of the immune responses. Without vitamin C, you would be likely to contract scurvy and this can happen within a month of a low to no vitamin C intake.

So, is it good?  

In conclusion, the carnivore diet is a very unique and controversial method of improving your health. With health benefits from nutrient dense foods including easy weight management and reduced inflammation, it seems that this diet may actually improve your health. However, the diets supportive evidence is controversial and mostly contradictory to what health professionals would advise. It is worth mentioning that because this diet is relatively new, there have been no long-term studies into the effects on health in the long run. For example, carnivore advocate Shawn Baker has been following this diet for less than 5 years and appears to be healthy and physically strong, but what would happen after 10 years? Would such a high intake of processed meat cause cancers to develop? Would he become deficient in nutrients? Would the lack of fibre in his diet cause him to develop digestive issues? The point I am trying to make here is that no one knows, and therefore no one can confirm if it is truly safe to follow. As well as a lack of strong supportive evidence from research, elimination diets such as this, are often not advised due to missing out on essential nutrients, or at least not advised without first consulting a doctor.

Ideally, a healthy diet consists of a wide variety of foods from each food group – everything in moderation! The carnivore diet is great for quality protein and other nutrients, but it could be made so much better with the inclusion of fruit and vegetables. This would provide fibre to help digest the high meat content and also offer other essential vitamins and minerals.

References:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3845365/ https://www.ncbi.nlm.nih.gov/pubmed/8942407