Carnivore Diet Review: Safety, Benefits and Meal Plans

Most dietitians recommend eating a colorful array of foods and food groups, with an emphasis on vegetables. But some people say that eating just one food group could be better than all the rest.

Enter the carnivore diet: a meat-lover’s meal plan that embraces all and only animal products. Unlike other high-protein, low-carb diets, zero carbs are allowed.

Dietitians and medical experts say the fad is restrictive and dangerous – but supporters are relentless in their enthusiasm toward the approach. Here’s what you need to know.

The carnivore diet is a “zero-carbohydrate diet and an extreme version of the keto diet,” explains Hollie Zammit, a registered dietitian with Orlando Health in Florida. This diet consists of consuming only animal products and staying away from fruits and vegetables, plant-based proteins, processed foods or other sources of protein, fats and carbs.

There’s no gray area and no leeway for adding additional food groups, says New York City-based registered dietitian Jamie Feit, of Jamie Feit Nutrition LLC. “It’s basically eating eggs and bacon for breakfast, a steak for lunch and a cheeseburger and bacon for dinner,” – sans bun, mind you.

Weight loss, dieting structure, potential health benefits and personal goals are among the reasons why people pursue the carnivore diet. Proponents of the diet say it can help you avoid or reverse common ailments such as diabetes, obesity and autoimmune diseases. But studies backing up these claims are scarce – and many dietitians criticize the approach.

“I’ve had clients who’ve expressed interest to me around the carnivore diet, largely because they’ve seen notable people discuss it or it aligns with their interests or curiosities,” says Andy De Santis, a registered dietitian and published author in Toronto. The simplicity is also attractive to some, he adds.

“My overall view of the carnivore diet would have to be negative,” De Santis says. “It just omits too many important food groups. Keto is one thing – but the carnivore diet is so, so limiting, I don’t see its long term viability for practical purposes or for health purposes.”

“It’s not suited for anyone except for a lion, tiger or wolf,” says Dana Ellis Hunnes, a senior clinical dietitian at UCLA Medical Center, assistant professor at UCLA Fielding School of Public Health and author of “Recipe For Survival.” “It is dangerous for humans to eat this way and is terrible for our microbiome, heart health and the environment.”

Hunnes isn’t alone in this train of thought. Amy McMahon, a registered dietitian nutritionist and coaching services practitioner at Teladoc Health, a telemedicine and virtual health care company headquartered in Purchase, New York, adds that the carnivore diet is “only suited for some animals,” such as the lion at the closest zoo – but not humans.

People on the carnivore diet can eat all meat products – and only meat products. Really.

For meat eaters who are interested in trying the carnivore approach to eating, you’ll have to cut out all plant foods. Yes, really. The goal is to exclude all carbohydrates, and that includes fruits and vegetables.

Followers of the diet are instructed to eat any kind of meat and meat products, from fatty cuts of beef, lamb, pork and organ meats to poultry, fish, eggs and dairy products. Some versions of the diet allow for eating animal byproducts, like dairy, too.

If you’re looking to increase your protein intake, the carnivore diet will do that – at a cost.

“The only real health benefit that this dietary approach may result in is an easy way to get enough daily protein,” McMahon says. “However, keep in mind that protein sources should be varied and can be found in other foods such as Greek yogurt, beans, edamame and nuts.”

Zammit adds that while the diet can be viewed as an extreme elimination diet, “by slowly reducing intake of carbohydrates and plant-based food items and increasing intake of animal protein,” it has some differences.

“Oftentimes on an elimination diet, food items may be slowly reintroduced, but that’s not the case here,” Zammit explains. “The ultimate goal is 100% intake of animal-based protein.”

Adrienne-Rae Velasquez, a registered dietitian with Pomona Valley Hospital Medical Center in Pomona, California, notes that “the carnivore diet is different from other extreme diets like the ketogenic diet because instead of looking for ‘net carbohydrates,’ the diet has no interest in supplying foods that may be higher in fiber or phytonutrients.”

A typical menu for a day on the carnivore diet can be:

“There’s no flexibility for a bun on your burger or a piece of fruit for dessert,” Zammit says.

Organ meats are highly nutritious, being rich sources of B vitamins, several minerals, including iron, magnesium and zinc, and fat-soluble vitamins, such as vitamins A, D, E and K. Organ meat and animal meat in general contain high levels of protein. It’s also true that our hunter-gatherer ancestors ate every part of the animals they hunted, nose to tail.

Yet plant-based diets, such as the Mediterranean diet, have long been favored by many dietitians and doctors as the healthiest and most sustainable way for humans to eat for longevity and wellness. The carnivore diet turns that conventional and well-established advice on its head.

The carnivore diet may offer potential benefits such as weight loss and relief from certain health conditions for some individuals. However, the diet also comes with a set of risks.

Short answer: It’s not. The lack of robust evidence in favor of the carnivore diet, however, isn’t stopping its supporters from promoting it.

One of its primary advocates, Dr. Paul Saladino, a physician in private practice in San Diego and author of “The Carnivore Code: Unlocking the Secrets to Optimal Health by Returning to Our Ancestral Diet,” claims that the carnivore diet can be the source of healing for virtually any autoimmune or chronic disease you might be experiencing, from depression and rheumatoid arthritis to diabetes, acne and obesity. There is limited or mostly anecdotal evidence for these claims.

A few of the commonly cited – but not proven – benefits of the carnivore diet include:

One commonly cited benefit of the carnivore diet is an improvement in gut health. Proponents suggest that zero-carb diets like the carnivore diet may be able to cure SIBO, or small intestinal bacterial overgrowth. SIBO is a common condition that occurs due to bacteria overgrowth in the small intestine that can cause bloating, constipation, diarrhea and other gastrointestinal problems.

While SIBO is a real condition, the carnivore diet isn’t currently a real, medically established cure. Due to a lack of studies, there is not enough evidence to say the diet helps with curing this condition – or many others. Of the research out there, one very small, six-person study (that has not been peer-reviewed or validated) found that five participants who followed a zero-carb, zero-fiber carnivore diet for at least four weeks tested negative for SIBO at the end of the observation period.

Studies have also linked carnivore – or meat-heavy – diets to an increase in GI issues. Another small study published in the journal Nature in 2014 found that in just five days, participants who switched to a zero-carb, carnivore diet experienced significant detrimental changes to the gut microbiome, including a dramatic increase in strains of bacteria in the gut that cause inflammation and have been linked with Crohn’s disease and ulcerative colitis.

A 2017 study found that dietary changes can rapidly alter the composition of the gut microbiome for both benefit and detriment, depending on the specific changes being made. In addition, a 2021 study compared changes in the microbiome over the space of four weeks on a vegan diet versus four weeks on a meat-heavy diet and found that many of the changes were individualized person-to-person, based on other factors.

The carnivore diet may result in weight loss for some people. But that doesn’t mean it’s healthy, and rapid weight loss can be dangerous for some people.

One of the main reasons an all-meat diet may result in weight loss is because it’s high in fat, Zammit says. High-fat foods promote meal satiety, meaning that you’ll feel fuller longer, she adds. “Feeling satiated from consuming these food items can help reduce your caloric intake, as you won’t feel as hungry, likely leading to weight loss.”

Sara Riehm, a registered dietitian and certified specialist in obesity and weight management with Orlando Health in Florida, adds that the carnivore diet encourages followers to minimize their intake of high-calorie, processed foods. This can create a calorie deficit, which means people are using more energy than they are consuming, and promote weight loss.

This isn’t always a good thing, as “severe calorie deficits can compromise our muscle stores and put us at risk for malnutrition,” she adds. Daily calorie needs vary for everyone, and it’s best to consult with a registered dietitian if you’re interested in losing weight.

Reducing your intake of carbohydrates may also help with blood glucose control, which may be a plus for people with diabetes.

Too much glucose can impact blood sugar levels. Over time, this can lead to the development of Type 2 diabetes.

Results from a social media-based survey of people who had followed the carnivore diet for at least six months were published in the December 2021 issue of Current Developments in Nutrition. The survey found that participants with diabetes reported benefits related to diabetes and insulin resistance, with 74% saying the condition had “resolved” and 24% saying it was “improved.” The survey authors noted that “all respondents with diabetes discontinued noninsulin injection agents, 84% discontinued oral medications and 92% of participants with Type 2 diabetes mellitus discontinued insulin.”

While such results may seem overwhelmingly positive, it’s worth keeping in mind that surveys such as this rely on self-reporting and are not considered the gold standard for scientific studies. Zammit cautions against confusing thoughts and feelings with scientific understanding.

“These claims are not based on sound science, but rather anecdotal reports,” Zammit says

Riehm adds that “decisions about your health should always be based on evidence-based information backed by science.”

Most registered dietitians strongly discourage the adoption of the carnivore diet.

“Frankly, this is not a healthy diet,” says Antonette Hardie, a registered dietitian with the Ohio State University Wexner Medical Center in Columbus. She cites several health risks associated with this diet, including:

Eliminating all food groups from your diet except one is not a risk-free endeavor. As an oncologist, Zammit warns of the carnivore diet’s cancer risks.

“It’s well known that a diet heavy in red and processed meats can increase risk of stomach and colorectal cancer. We also know that a diet rich in saturated fat can increase risk of liver cancer,” she adds.

“We have strong evidence from several meta-analytical studies that demonstrate a plant-based diet can greatly reduce your risk of several cancer types, as well as other disease states, including cardiovascular disease and diabetes,” Zammit says.

Velasquez notes that as a registered dietitian, she wouldn’t recommend this diet to anyone because of the very high intake of red meat, which is “one of the leading carcinogens that we consume regularly. Several cancer studies have alluded to a high consumption of red meat and increased risk of colon or rectal cancer.”

One major drawback of the carnivore diet is that many of the foods that are encouraged are high in saturated fat and cholesterol.

On the carnivore diet, heart-harming saturated fat intake rises, and healthy unsaturated fat intake falls. Unsaturated fats from sources like avocados and nuts “are protective for our brains and heart health,” McMahon says. “Those fats are not allowed on the carnivore diet.”

Riehm notes that “numerous studies have shown that consuming excessive amounts of saturated fat and dietary cholesterol can increase cholesterol, clog arteries and increase our risk for heart disease. While these foods can be included in a balanced diet, it’s important to consume them in small portions to avoid compromising our health.”

For these reasons, Feit says the carnivore diet “is definitely a fad diet. Although it may have proposed benefits, it’s important to realize that this can never be considered a healthy diet. As stated by the American Heart Association, saturated fats need to be replaced by unsaturated fats in order to decrease heart disease, which is a leading cause of death. A diet consisting of all food groups is always a better way to go.”

Elevated cholesterol levels can lead to atherosclerosis, heart attack and stroke. “If you have a personal or family history of cardiovascular disease and hyperlipidemia, the carnivore diet is not for you,” Zammit says.

Another potential concern with the carnivore diet is the risk of developing nonalcoholic fatty liver disease, or NAFLD. NAFLD is when people who don’t drink excessive amounts of alcohol accumulate excessive liver fat. The condition can increase people’s risks for obesity, diabetes and high cholesterol.

“(This disease) is caused by the accumulation of saturated fat. This isn’t always reversible by changing your diet,” Zammit says. “When we have this buildup of saturated fat, it can cause inflammation of the liver, increasing the risk of liver cancer.”

A 2022 study published in BMC Gastroenterology found that diets heavy in red meat, sweets, fast foods and refined grains increase the risk for NAFLD.

The carnivore diet is also a poor choice for people with chronic kidney disease even if they aren’t on dialysis. “With chronic kidney disease, you’re instructed to actually limit your protein intake,” Zammit explains.

She adds that “the average protein needs of a healthy individual are 40 to 65 grams per day. When you have CKD, your kidneys no longer have the ability to remove protein wastes, which will then build up in the blood and can cause a whole host of unpleasant symptoms, including nausea and vomiting, decreased appetite and weakness.”

Jonathan Valdez, a registered dietitian nutritionist and owner of nutrition service Genki Nutrition, says that it’s important to remember that people who do not have chronic kidney disease do not have to limit their protein intake so drastically. Still, he says there are notable benefits from non-animal proteins, like pistachios.

Valdez adds that if discussing the carnivore diet with a hopeful client, he would start out by addressing pros and cons but ultimately recommend against partaking in it.

“I would never recommend a carnivore diet,” Valdez says.

According to Valdez, a carnivore diet is a recipe for constipation and cardiovascular disease.

Because the carnivore diet is bereft of all plant matter, it contains virtually no fiber. “Due to the lack of fiber, most people will end up with constipation,” Zammit says.

Hunnes adds that subsisting solely on animal products will increase IGF-1 in the body. That hormone, called insulin-like growth factor 1, can lead to increased inflammation throughout the body that can in turn cause a number of additional problems.

“It will destroy the (gut) microbiome because it is highly acidic and produces a lot of TMAO, an inflammatory compound that is extremely detrimental to the microbiome,” Hunnes says. Studies into exactly how the gut microbiome influences health are ongoing, but scientists are unraveling the myriad ways a healthy balance of bacteria in the gut may influence good health throughout the body.

“Since the carnivore diet is lacking in produce, it’s possible to experience micronutrient deficiencies as certain vitamins and minerals are hard to source from meat alone,” Velasquez says.

In particular, Zammit says the lack of vitamin C increases the risk of scurvy. A disease that was common among sailors in the 18th century, scurvy causes swollen and bleeding gums, anemia, loss of teeth, weakness and poor healing of wounds, and it can be deadly.

“If there is a large weight drop in a short time because of switching to a previous diet, you can be at risk for electrolyte imbalances, kidney stones and kidney failure,” Valdez adds.

In addition to the medical and nutritional issues one may encounter on a carnivore diet, you also need to consider the psychological aspect of following a restrictive diet before you adopt this approach to nutrition.

Zammit explains that “following any restrictive diet can often lead to loneliness and social isolation. It can build distrust with yourself, disconnecting the relationship you have with your body and food. All this can affect your quality of life in a negative way, especially if following long term.”

As such, if you have a history of eating disorders, you’d be well advised to avoid this diet.

McMahon notes that as a total elimination diet, the carnivore diet “should be considered a red flag and avoided.” She also points out that carbohydrates are our brains’ preferred energy source and eliminating this source can lead to fatigue or mood changes.

Lastly, if you’re undertaking the carnivore diet in an effort to lose weight, be aware that rebound weight gain can be an issue when you inevitably tire of this limited diet and begin adding back other foods.

“With such a restrictive diet, you are prone to gain weight back and then some,” Hardie says.

Hunnes points out that risks to human health are not the only drawback to the carnivore diet. “It’s also terrible for the environment. Animal foods are one of the most environmentally destructive things on the planet. If humans reduced our meat consumption, we could save huge amounts of land, water and emissions every year.”

She notes that meat production consumes 10 times as much water as plant-based forms of protein. Farming meat also uses 10 times as much land as an equal amount of plant protein requires.

Meat production is also responsible for large parts of deforestation in the Amazon, and it releases 100 times as much carbon dioxide into the environment as plant-based proteins, Hunnes says. “It is truly one of the most destructive things we can eat for the environment, but also for our health.”

Despite experts’ concerns, there are a growing number of ardent fans of the diet. It’s been endorsed by extreme athletes and celebrities like Joe Rogan. Saladino says going carnivore is the solution to a range of health issues currently plaguing humankind. Plants, he says, simply aren’t cutting it.

“If you look at the incidence of chronic disease, no one can deny that in the last 70 years, we’ve become abysmally unhealthy,” Saladino says. “The question is, what the heck happened?”

Saladino doesn’t connect poor health to unhealthy behaviors, which he claims have “gone way down” in recent years. Instead, he credits eating patterns – and what he says are misconceptions about healthy diets.

“If you look at the number of people who are eating ‘healthfully,’ that’s gone way up. But that’s just according to the U.S. dietary guidelines,” Saladino says.

He notes that red meat often bears the blame for many ailments and chronic diseases, which he thinks is backward. Plants, he says, can be more toxic and poisonous.

However, while some plants are toxic and poisonous, the ones that are deemed edible are not. The U.S. Department of Food and Agriculture regulates the safety of produce and other foods along with the Food and Drug Administration and Centers for Disease Control and Prevention. Further, studies have linked excess red meat consumption with increased risks of cardiovascular diseases and cancers.

In fact, there aren’t many studies in support of an all-meat eating pattern. And those that exist tend not to be robust or peer-reviewed.

Dena Champion, a registered dietitian with the Ohio State University Wexner Medical Center in Columbus, says that most research on the carnivore diet is anecdotal evidence or opinion articles, where linked scientific studies “are taken completely out of context or interpreted incorrectly.”

Champion adds that there “no known long-term health benefits” of the carnivore diet, and supporters “seem to ignore the mountains of quality research that has proven repeatedly that plant-heavy diets are best for long-term health.”

Typically, meat products cost more than plant-based foods, and as such, you may have to shell out more money than you realize to follow this diet.

“Although you won’t be spending money on the food items you used to include, you’ll make up for it and then some by having to purchase animal protein for all your meals,” Zammit says.

This cost is compounded by the fact that the diet encourages only using “grass-fed and ethically sourced protein, which is very expensive, and not everyone has the privilege to obtain, depending on their neighborhood and socioeconomic status,” she says.

While there’s no reason why one can’t healthfully incorporate meat and animal products into their diet if they choose, focusing on meat-based foods alone doesn’t make for a healthy eating pattern, Champion notes. “Plants are loaded with vitamins, minerals, fiber and phytochemicals important for long-term health.”

Zammit adds it’s important to remember that “when it comes to your overall health, diet is just one piece of the puzzle. Genetics, age and gender play a huge role in how your body reacts to certain food items or diets, and this isn’t something we can change.” These factors can account for why some people have had success on a carnivore diet, while others can’t sustain it.

She also warns about being careful when comparing yourself to other people. “The human body is incredibly complex,” she points out. “There are no ‘bad’ foods, just bad overall diets. Behavior and lifestyle modification are still the best predictors of your health and happiness. At the end of the day, nourish your body based on your individual needs and preferences.”

If you’re thinking of beginning a particular diet, it’s important to connect with a local registered dietitian to help educate and guide you.

If you’re looking for a healthy way of eating, Hardie notes that “there is so much more research out there that promotes a plant-based diet or Mediterranean diet versus any other fad diet. The carnivore diet is just another fad diet that isn’t sustainable over time and can lead to several chronic illnesses, such as high cholesterol and heart disease.”