The carnivore diet: why it’s not good for your health

What is the carnivore diet?

The carnivore diet is an extremely restrictive diet that’s grown in popularity mostly via social media as a quick way to lose weight over the last few years. It’s made up of only animal products: meat, fish, seafood, eggs and some dairy products like butter.

It does not include any plant-based foods or carbohydrates such as fruits, vegetables, grains, nuts or seeds.

This means it is high in saturated fats and protein, and contains very little carbohydrates and fibre.

It’s an extreme version of other low-carb diets, such as the keto or Atkins diet.

Is the carnivore diet healthy?

The carnivore diet is not healthy and may have serious consequences for your health.

One of the main issues is that it’s high in saturated fats due to its high amounts of red meat and dairy.

Too much saturated fat can increase levels of bad cholesterol (known as non-HDL cholesterol) in the blood.

Processed meat can also be high in salt, which can increase your risk of high blood pressure.

Both high cholesterol and high blood pressure raise the risk of developing coronary heart disease and having a heart attack or stroke. That’s why the NHS recommends eating 70g or less of red or processed meat a day.

Furthermore, eating a lot of meat means eating a lot of protein that can put stress on your kidneys.

The carnivore diet is also missing many nutrients from fruit and vegetables that are needed for the body to work properly.

For example, the diet contains virtually no fibre, which is a type of carbohydrate only found in plant-based foods that cannot be completely digested.

Fibre has been shown to reduce bad cholesterol levels, help with digestion and prevent constipation, and is strongly linked with a lower risk of heart and circulatory disease.

Because of these reasons, the NHS recommends eating a well-balanced diet that includes the recommended amounts of all 5 main food groups:

• fruits and vegetables
• high-fibre foods like wholegrain breads, cereals, pasta and rice
• dairy and dairy alternatives
• proteins such as meat, beans, pulses, fish and eggs
• healthy unsaturated fats like vegetable oils.

You can follow these recommendations by eating a Mediterranean diet that includes high levels of vegetables, fruits, beans and cereals, plus moderate amounts of fish and white meat.

Are there any benefits?

While some people report benefits from the carnivore diet such as weight loss, improved blood sugar levels and reduced inflammation (see below), overall scientific research on its long-term health benefits is limited and inconclusive.

Can the carnivore diet help you lose weight?

While high protein, low-carb diets may help with weight loss in the short term, there’s no consistent scientific evidence that they are more effective than other weight loss approaches in the long term.

The idea that the carnivore diet can help weight loss is based on the principle that eating very little to no carbs – and eating more protein and fat – will start a process in your body called ketosis. 

This is where your body burns fat instead of carbohydrates. Other diets that use the same principle are the Atkins diet and the keto diet, which takes its name from ketosis.

However, there are other reasons these high protein diets may aid weight loss. 

Foods that are high in protein are often more filling, which could help lower the overall amount of food you eat while on these types of diet.

They also require cutting out many high calorie foods and drinks such as crisps, cakes and alcohol (but not processed meats like bacon) which may contribute to weight loss more than ketosis itself.

But because the carnivore diet is so restrictive, it may be hard to stick to. This means it’s not a realistic way to lose weight in the long term.

Instead, there’s strong evidence that the Mediterranean diet can support weight loss, while being much more practical too. 

Can the carnivore diet lower blood sugar?

The idea that the carnivore diet can lower blood sugar levels comes from the principle that eating protein and fats does not raise blood sugar levels as much as eating carbohydrates, which are broken down by the body into sugar (glucose).

If you lose weight on the diet this can help lower blood sugar levels too.

In line with this, Diabetes UK says eating fewer carbohydrates – less than 130g of carbs a day – may help lower blood sugar levels in the short term for people with type 2 diabetes.

For context, one large jacket potato can contain up to 90g of carbs, while a slice of bread or an apple is around 15g to 20g.

But Diabetes UK does not recommend cutting carbs out altogether as they contain essential fibre, vitamins and minerals. And it warns that people with type 1 diabetes should not follow a low-carb diet.

Can the carnivore diet reduce inflammation?

Another false claim is that the carnivore diet reduces inflammation (the body’s response to illness or injury), and that avoiding plant-based foods can improve and even ‘heal’ autoimmune conditions.

This claim is based on research around lectins, a plant protein found in legumes, that says they can contribute to inflammation if eaten raw or undercooked.

However, most plant-based foods are anti-inflammatory and are known to support health. In fact, fruits and vegetables are naturally high in molecules called antioxidants that may help to reduce inflammation.

Another claim is that the carnivore diet is high in omega-3 fatty acids from oily fish and grass-fed meats, which may help to lower inflammation. But processed and red meat, which are a core part of the diet, are associated with increased inflammation.

The lack of fibre in the carnivore diet could also impact your immune function, as the healthy bacteria in your gut that feed on fibre play an important role in your body’s immune response

Do any studies support the carnivore diet?

Very few studies have looked specifically at the effects of the carnivore diet on overall health.

One study that attempted to do so was published in the journal Current Developments in Nutrition in 2021. It surveyed 2,029 people recruited from online carnivore diet groups who had followed the diet for over 6 months.

The researchers from the United States found 95 per cent of the participants reported better overall health, and 69 per cent reported improvements in chronic health conditions including excess weight, blood pressure and blood sugar levels.

However, the researchers themselves say the results need to be “interpreted cautiously” because of “several major” limitations in the study’s design.

The main one being that the participants self-assessed their diet, nutrition status and health outcomes, like improvements in chronic disease and weight loss, with no medical tests or measurements taken to verify what they reported.

Also, the study did not include people who had stopped the diet before 6 months due to negative health effects, the researchers noted.

The BHF verdict

We do not recommend eating the carnivore diet.

While it may help with weight loss and better blood-sugar control for some people, the diet is very restrictive, unbalanced and potentially unhealthy in the long term, especially for heart health.

Extreme diets high in saturated fat and low in fibre increase the risk of high cholesterol, which has been scientifically proven to raise the risk of heart attack and stroke.

The Mediterranean diet, which includes plenty of fruits, vegetables, wholegrains and seeds, has been continually shown to support overall health in the long run.

If you’re considering trying the carnivore diet, it’s essential to choose heart-healthy fats and high-quality protein sources such as lean meats, poultry, fish (including oily fish) and eggs, plus high-fat plant foods like nuts, seeds and avocados to make sure you get enough fibre and vitamins.

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