Can the meat-only ‘carnivore diet’ really be good for your health?

The grand final-winning Penrith Panthers players believe it gave them a victorious edge. Proponents on social media call it a “healing” diet that can help you reclaim your health, strength and vitality. And its popularity continues unabated, despite it being widely discouraged by health (and climate) experts, with large studies linking high meat consumption variously with an increased risk of type 2 diabetes, cardiovascular disease, colorectal cancer, and dying earlier.

So, what is it about the carnivore diet that is so bad and yet, according to the people who swear by it, so good?

Mike Scanlan, 41, turned to a pure carnivore diet nearly five years ago.Credit: Edwina Pickles

Diet of champions?

There are various iterations of the carnivore diet – some include seafood, fruit, honey, eggs or dairy, while “purists” eat strictly red meat and salt only. Whichever way you cut it, there can be psychological appeal in consuming a diet of mostly, or entirely, animals.

This may be particularly the case for athletes, says Professor Ben Desbrow, an accredited practising dietitian and the head of performance nutrition at the Gold Coast Titans.

It’s not just a “secret diet” of the Panthers but has become popular across various combat sports, including rugby league.

“It’s a collision, aggression-based sport, and they like being the king of the jungle,” Desbrow says. “And so, from a dietary point of view, it plays into that sort of mindset.”

He adds that restrictive diets may also serve another psychological purpose: “[Being] disciplined in your food intake sort of separates you from the average person.”

One 2023 study of more than 2000 people who followed the carnivore diet (67 per cent were men in their 40s) found few experienced adverse effects and participants reported high levels of satisfaction and improved overall health.

But there may be several physiological benefits that explain this.

“It helps to increase protein intake, which is important for muscle and skeletal health, and it can help to balance blood sugar levels for those with insulin resistance or type 2 diabetes,” says Amelia Phillips, a registered clinical nutritionist and exercise scientist.

“And like any diet, when you start to pay attention to what you eat, invariably your diet quality improves.”

The improvement in diet quality, and what you invariably cut out, accounts for many of the improvements that people experience.

“If you are having a typical Western diet – a lot of junk, refined processed foods, a lot of meat, a lot of alcohol – remove that for six months, you will drastically change your health, no doubt,” says Professor Luigi Fontana, an expert in nutrition and healthy longevity and scientific director of the Charles Perkins Centre Royal Prince Alfred Clinic at the University of Sydney.

Is going cold turkey a pathway to better health?

Mike Scanlan, a 41-year-old banker from Sydney’s east, turned to a pure carnivore diet nearly five years ago.

He had long suffered with autoimmune issues such as asthma, allergy and eczema, which deteriorated into regular headaches, migraines, extreme lethargy and anxiety.

Scanlan was not coeliac and specialists were unable to determine the cause, suggesting medication to treat the symptoms. Depressed and feeling hopeless, he began experimenting with nutrition, recalling an uncle whose migraines had improved after removing gluten and dairy.

When his symptoms didn’t improve after trying whole foods only, low-FODMAP, the GAPs diet and keto, he decided to try a more extreme approach.

On podcasts and in books, Scanlan had heard people say they’d cured autoimmune issues through a carnivore diet.

The argument, according to advocates, is that plants “do not want to be eaten” and evolved to defend themselves with toxic chemicals. Paul Saladino, a popular psychiatrist-cum-carnivore influencer, claims these chemicals can“damage your gut; inhibit nutrient absorption, mess with your hormones, and generally, make you fart a lot”.

By cutting out plant foods (along with dairy and fruit, depending on the version), Saladino and others suggest people cut out the cause of inflammation and autoimmune dysfunction in the body.

Scanlan thought it was “bonkers”, but he was desperate.

From someone who once ate cereal for breakfast and dessert, toasties for lunch and pizza or pasta for dinner, his diet now consisted of two meals a day: either slow-cooked lamb or steak with biltong and hamburger patties for breakfast followed by a rib-eye for lunch.

It was a revelation. He felt better, his mood improved and, except for high LDL cholesterol, his metrics at annual health checks have remained solid. His experiences, along with a newfound belief in the Saladinos of the world, have made him sceptical about traditional health advice, including that LDL is bad in the absence of plaque.

“I’ve never felt this good, I open my eyes and feel rested,” he says. “I don’t get tired or hungry. I thought this would wear off, but it’s been five years.”

A healing or unhealthy approach to eating?Credit: Getty Images/iStockphoto

A bad cut of meat?

Some extreme diets show promise in treating medical conditions. The FODMAP diet, for instance, is said to help manage IBS, and the ketogenic diet is often recommended for managing epilepsy and potentially diabetes.

“If someone has conditions they would like to manage through diet, there is the possibility that a restriction diet may help them in the short term,” Phillips says. “However they should embark on this under the care of an experienced dietitian.”

Autoimmune diseases are increasing in parallel with the consumption of ultra-processed foods high in fats, trans fatty acids, cholesterol, proteins, simple sugars and salt. It is thought that this Western-style diet is partly to blame.

While opting for whole foods (including meat) can help, depriving the intestinal gut microbiota of dietary fibres found in fruit, vegetables, legumes and whole grains may ultimately degrade the gut and the immune system. Dietary fibre is rarely consumed in adequate amounts.

Although Fontana says the quality of meat makes a difference (grass-fed v grain-fed, a steak v processed meat), high consumption – particularly in the absence of a diverse range of whole foods – is unhealthy in the long term, as it drives ageing and cancer pathways.

He points out that excessive amounts of saturated fat drive high blood cholesterol; choline and l-carnitine (high levels are found in animal products) ferment in the gut to produce a substance called TMAO that accelerates the formation of coronary atherosclerotic plaques; excess iron drives oxidation and colon cancer; high levels of methionine and branched-chain amino acids activate the IGF/mTOR pathways and can promote insulin resistance, type 2 diabetes, cancer and accelerated ageing.

“The body has ways to compensate for years before you develop problems,” Fontana says.

Meat and plants don’t need to go head-to-head. Balance is generally best.Credit: Getty Images/iStockphoto

Balance is boring but beneficial

When I make the point made by many carnivores that the Inuit lived on meat and did not have issues with heart disease or colon cancer, Fontana is blunt: “Their lifespan was very poor”.

And as for the defence chemicals in plant foods, most experts agree that the abundant nutrients they contain far outweigh any possible harm.

One recent meta-analysis of 31 prospective cohort studies suggests that intake of plant, but not animal, protein is associated with an 8 per cent lower risk of all-cause mortality, and a 12 per cent fall in cardiovascular disease mortality.

Desbrow isn’t dismissive of approaches like carnivore, but says athletes looking for improvements in performance, body composition or focus can typically find them by manipulating their diet without eliminating entire food groups. Carnivore and other extreme approaches are, in his view, “not a long-term solution”.

If people want to live longer and healthier lives, a diverse, balanced diet may seem boring but is the key, agrees Phillips.

“Unless there is a clear medical reason, no one should be eliminating whole food groups – except for ultra-processed and highly processed foods, which we know are not actually food groups,” she says.

“We don’t need to go extreme and cut out multiple food groups to be healthy. And we can’t forget that food is there to be enjoyed, so let’s find a sustainable balance that nourishes not just our body but our soul too.”

Make the most of your health, relationships, fitness and nutrition with our Live Well newsletter. Get it in your inbox every Monday.