Carnivore diet explained: What it is, benefits and risks
Imagine a diet where no fruit and vegetables pass the lips but plenty of meat is encouraged.
Welcome to the carnivore diet, sometimes known as the zero-carb diet, which consists solely of animal products such as meat, eggs, and limited dairy. No nuts, seeds or legumes are consumed. The diet has gained prominence through social media by influencers, dubbed “meatfluencers” who claim it has a range of benefits and can lead to dramatic weight loss – with very little evidence to prove their point.
As such, it has been criticised by nutritionists and dieticians for being nutritionally restrictive.
“It is a strict form of diet, with the emphasis purely on protein and fat, as opposed to carbohydrates. It has gained popularity along with the belief that reducing carbohydrates in your diet is a good thing,” says Rob Hobson, a nutritionist.
Skip to:
What exactly is the carnivore diet?
The carnivore diet only allows consumption of meat, poultry, eggs, seafood, fish, some dairy, and water. Advocates encourage fattier cuts of meat to ensure enough calories are consumed.
The diet is a type of ketosis eating plan in which the body switches from burning glucose fuel in the blood and liver to burning stored body fat. Without glucose from carbohydrates the liver breaks down fat stores to produce energy in the form of ketones.
A typical meal day on the carnivore diet may include a breakfast of bacon and eggs, lunch of salmon with bone broth and a dinner of steak with bone marrow.
What is the history of the carnivore diet?
Different variations of the carnivore diet have been historically documented. For example, in the 1870s, the Italian physician Arnaldo Cantani put diabetic patients on an exclusive animal-based diet. In the 1880s, James H Salisbury advocated a meat diet consisting of two to four pounds of lean beef and three to five pints of hot water a day. It became known as the meat and hot water diet, or Salisbury diet.
More recently, the orthopaedic surgeon and influencer Shawn Baker published The Carnivore Diet book in 2018.
What can I eat on the carnivore diet?
Red meats, including beef, lamb, pork and venison
Offal, such as liver and kidney
Poultry
Fish
Eggs
Bone marrow
Lard, dripping, butter and ghee
Limited low lactose milk, yogurt, and cheese
What should I avoid on the carnivore diet?
Vegetables
Fruit
Nuts and seeds
Legumes
Grains, including food made from them, such as pasta and bread
High-lactose dairy foods
Alcohol
Sugars
Drinks other than water
Benefits and health claims of the carnivore diet
There have been limited studies to test the claims of the diet. One 2021 study surveyed 2,029 people who had been on the carnivore diet for at least six months. The authors recorded surprising results. All the diabetics in the cohort said they came off injectable medication and 92 per cent said they came off insulin completely. The average weight loss across the cohort was 20lbs.
The research, however, was limited as it was based on a self-reported online survey and not tested through randomised control trials. The study concluded: “Contrary to common expectations, adults consuming a carnivore diet experienced few adverse effects and instead reported health benefits and high satisfaction.”
The authors, unsurprisingly, called for more research.
According to Kate Booker, a nutritionist at Nutrition Geeks: “Some people may be getting mineral rich and bioavailable nutrients if the meat consumed is high quality, regenerative and raised organically.”
Hobson adds: “If you’re not eating carbs you will likely have stable blood sugar levels, purely because you’re just eating fat and protein, although some of that protein will turn to glucose so you will still end up with glucose in your bloodstream.”
Potential risks of the carnivore diet
Meat-heavy diets may exceed recommended saturated fat levels, raising heart disease risk.
High sodium intake could lead to hypertension. A diet high in animal products, particularly red and processed meats, has been associated with an increased risk of chronic diseases such as heart disease, certain cancers, and Type 2 diabetes.
The diet lacks the essential plant micronutrients and antioxidants found in fruits, vegetables, wholegrains and legumes
It has a significant lack of fibre, which is essential for gut health and function, and is associated with a lower risk of heart disease, bowel cancer and Type 2 diabetes
Lack of fibre is also likely to cause constipation
Unsuitable for certain groups, including children, pregnant or lactating women, as well as those who have been diagnosed with impaired kidney function
The exclusion of carbohydrates means the body misses out on a great food for the nervous system and thyroid
The diet lacks essential nutrients like vitamin C, and polyphenols. Without careful planning and supplementation, followers of the carnivore diet may be at risk of nutrient deficiencies, which can lead to health problems over time
Limited food choices can hinder social interactions, making it challenging to dine out or share meals with others
Potential risk for disordered eating
Lack of long-term research
Carnivore diet reviews and experiences
Hobson’s assessment: “People are sucked into it because you probably are going to lose weight in the initial stage because you’ve cut out the carbs and you’re eating very filling foods. You might also go into ketosis and start burning fat. Initially people might like the idea of being able to eat bacon and eggs everyday, but it soon becomes very limiting.
“I wouldn’t recommend it because it is unsustainable and with any eating plan that cannot be done long term we generally find people go back to their former eating habits.”
Diabetes UK assessment: “Proponents of the carnivore diet argue that it is a natural and evolutionarily appropriate diet for humans. It is proposed that our ancestors ate mostly animal products, and our bodies are well adapted to digesting and utilising them. However, as it is a relatively new diet, there is limited scientific research on the long-term effects of a carnivore diet.
“Some small studies have suggested that a carnivorous diet may improve markers of health, such as weight loss, blood sugar control, and inflammation. However, these studies have been small and short-term, and more research is needed to fully understand the potential benefits and risks of such a diet.
“A carnivore diet can be nutritionally inadequate and lacks essential nutrients found in plant-based foods, that’s why it’s important to consult with a doctor or a dietitian before adopting such a diet.”
Dr Howard LeWine, a doctor and the editor of Harvard Health Publishing writes: “While some keto diets can emphasise the intake of healthier mono- and polyunsaturated fats, that’s not the case with carnivore diets. Animal fat is mostly saturated fat, which is the unhealthiest type of fat because it raises levels of LDL (bad) cholesterol.
“The disadvantage of all keto diets is they tend to raise LDL cholesterol levels in both the short and long term. Other longer-term concerns about keto diets, especially the carnivore diet, include the increased risk of kidney stones, gout, and osteoporosis.
“The very high protein intake associated with the carnivore diet can lead to impaired kidney function. Because keto diets induce the body to burn fat, all keto diets can jump-start a weight-loss program. But I would never recommend a carnivore diet for this purpose.”
Is the carnivore diet for you?
Booker concludes that the carnivore diet may benefit people who are reactive to plant foods, but only in the short term. “It’s not something I would recommend,” she says. “I’m not convinced. I believe we need high-quality animal foods along with plants that provide antioxidants, phytonutrients, and food for our gut bacteria. Carbohydrates are beneficial for us, this diet is pretty much no carbohydrates. Some on the carnivore diet do include fruit and honey which would be more beneficial.”
Bini Suresh, a dietitian, says that the diet may suit people seeking rapid weight loss, those who only eat a limited range of foods and those with plant food sensitivities. “However, it’s important to ensure adequate calorie intake and overall nutrient balance to support energy needs and performance,” she says.
“The carnivore diet may not be suitable for everyone, and individual responses to the diet can vary widely. Before starting the carnivore diet or making significant dietary changes, individuals should consult with a healthcare provider or registered dietitian to ensure that the diet is appropriate for their needs and health status.”
