Short-term side effects of the Carnivore Diet, like nausea, headache, Keto flu, constipation, and diarrhea, which may happen in some individuals, usually go away after a week or two as our body adapts to the new eating habit. But can we consider this diet a long-term option?
Highlights
A Carnivore Diet can help you lose weight, reduce inflammation, improve digestive health, etc.
Short-term side effects of the Carnivore Diet include headache, diarrhea, constipation, dizziness, irritability, cravings, etc.
Individuals with underlying health issues, pregnant or breastfeeding women, individuals with eating disorders, and those with gastrointestinal issues need to consult a healthcare professional first.
You can eat ruminant meat, poultry, seafood, eggs, and dairy on a Carnivore Diet.
What Is the Carnivore Diet?
The Carnivore Diet is not just a set of eating rules but a lifestyle toward healthy eating by eliminating unnecessary and harmful foods and focusing on whole, nutritious food sources.
The Carnivore Diet involves consuming animal products, such as meat, fish, eggs, and other animal-based products, while excluding plant-based foods, like fruits, vegetables, grains, legumes, nuts, and seeds.
Consuming animal products and avoiding plant-based foods increases fat and protein and minimizes carbohydrates, which creates a state of ketosis where the body burns fat instead of carbohydrates, leading to various health benefits [1].
"The Carnivore Diet can lead to significant improvements in inflammation markers, digestive issues, and autoimmune conditions for some individuals."
Join 50,000+ subscribers to get monthly emails on the best science-based tools and strategies for optimal health from Rina.
You'll also get Rina's exclusive Daily Blueprint. In it, Rina shares her daily routine. She also shares practical tools and protocols that you can use to heal inflammation and maximize your health.
Thank you! You're now subscribed!
Oops! Something went wrong while submitting the form.
We value your time and send just 1 insightful email monthly.
By submitting your email to subscribe, you agree to The Primal's privacy policy
Weight Loss
Obesity can cause different illnesses, including cancer, type 2 diabetes, cardiovascular disease (CVD), hypertension, obesity-hypoventilation syndrome (OHS), and sleep apnea [2].
So, it’s essential to maintain a healthy weight by doing regular physical activity and eating a proper diet, which can suppress appetite and reduce visceral fat while providing necessary nutrients.
Various studies have confirmed the positive effects of a low-carb ketogenic diet like Carnivore on weight loss. For example, a 2022 study showed that a low-calorie, high-fat, moderate-protein, and low-carb ketogenic diet can help weight control in overweight patients [3].
Also, a 2016 study on 20 participants receiving a very low-carbohydrate ketogenic diet for two months indicated significant improvements in anthropometric and biochemical parameters [4].
A 2019 study suggested that a very low-carbohydrate ketogenic diet can have beneficial effects on reducing chronic inflammation [5] [6].
Different studies, including a 2018 study, showed that a ketogenic diet can reduce inflammation and perform anti-inflammatory roles by blocking certain processes, like nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) activation [7] [8] [9].
Research published in the World Journal of Gastroenterology suggests that the Carnivore Diet may alter gut microbiota composition and reduce symptoms of inflammatory bowel disease (Source: World J Gastroenterol, 2021).
Improved Gut Microbiome and Digestive Health
A 2021 study on the effects of low-carb ketogenic diets on the digestive system indicated that such diets can positively impact the gut microbiome by improving overall adiposity, insulin resistance, and inflammation [10].
The following image, retrieved from a 2022 study on the effects of ketogenic diets on gut microbiota, summarizes the positive effects of low-carb diets [11].
A 2023 study on the impacts of ketogenic diets on cardiovascular diseases showed that ketone bodies, released from ketosis, can provide substitute fuel sources for the diseased heart by affecting its metabolism.
Also, this study suggested that ketogenic diets can do better in preventing and treating cardiovascular diseases [12] [13].
Improved Cholesterol Levels
A 2020 study indicated that a ketogenic diet, like the Carnivore Diet, can significantly improve Low-Density Lipoprotein (LDL) Cholesterol Levels [14].
Alleviated Certain Cancer Symptoms
Dietary habits can significantly reduce cancer risk, especially if the diets can help reduce body weight, decrease insulin levels, and target the metabolic weaknesses of cancer cells.
Researchers believe that a ketogenic diet can help lower cancer risk because it helps decrease the expression of ketolytic enzymes in cancer cells [15] [16].
Lower Risk of Diabetes
Type 2 diabetes causes insulin resistance, which can lead to other conditions like inflammation, decreased size of LDL particles, and endothelial dysfunction [17]. A healthy, low-carbohydrate diet can step in here and help glycemic control and improve lipid profiles in overweight patients with type 2 diabetes [18].
Carnivore Diet Improves Insulin Resistance
A study in The American Journal of Clinical Nutrition found that a very low-carbohydrate, animal-based diet (similar to the Carnivore Diet) improved insulin sensitivity and lipid profiles in participants with obesity (Source: Am J Clin Nutr, 2020).
Improved Autoimmune and Skin Conditions
Studies show that a ketogenic diet can help autoimmune and skin conditions as it can improve the gut microbiota, which is associated with various conditions, including autoimmune conditions, obesity, liver diseases, diabetes, cardiometabolic disorders, cancer, inflammatory bowel diseases, and mental disorders like Alzheimer’s, autism, depression, Parkinson’s, etc. [19] [20] [21] [22].
However, no dietary approach is all good for everybody, and there may be side effects for some individuals, especially while transitioning to a Carnivore diet.
Short-Term Side Effects of the Carnivore Diet
Any big changes in our eating habits bring about changes in our mood, digestive system, brain function, and many other parts of our bodies.
Short-term side effects of the Carnivore Diet mainly occur during the initial transition phase, when our body is adapting to the new eating system. These short-term side effects usually fade away after a week or two.
Also, please note that not everybody will experience these adverse effects, but it’s wise to know about them to make the best decisions regarding our health and fitness.
Although not enough studies have been conducted on the side effects of the Carnivore Diet, personal reports show that it may cause the following short-term side effects [23].
Brain Fog,
Headache,
Chills,
Muscle Soreness,
Sore Throat,
Digestive Issues (Diarrhea, Constipation)
Dizziness and Irritability,
Bad Breath,
Bad Taste in the Mouth,
Dry Mouth,
Cravings,
Nausea,
Cramping,
Rapid Heart Rate,
Electrolyte Imbalance.
Although these potential side effects usually go away after the initial days or weeks of going into a Carnivore Diet, we can boost this process with some easy steps.
Consume Enough Calories: Although you may feel full on a Carnivore Diet, as fat and protein in Carnivore foods make you feel satiated, you still need enough calories to go through the day. Find out your ideal daily caloric needs (you can consult a healthcare professional) and consume enough food to provide the needed energy, which helps reduce headaches, brain fog, dizziness, and irritability.
Stay Hydrated: You may lose fluids in the early days of going on a Carnivore Diet as your body adapts to the new eating habits, so you must drink plenty of water to avoid dehydration and its side effects.
Keep Electrolytes Balanced: You can add some extra salt to your Carnivore dishes, consume electrolyte drinks, or take electrolyte supplements after consulting a registered dietician or physician.
Do Regular Physical Activity: Doing regular physical activity helps you sweat, which is an effective way to get rid of toxins and naturally rebalance your electrolyte levels.
Similar to the short-term side effects of the Carnivore Diet, there are no detailed studies on the long-term effects of the Carnivore Diet. Anyhow, some conditions are thought to appear after a long time on a ketogenic diet like Carnivore.
Several case studies and anecdotal reports suggest that the Carnivore Diet can lead to significant improvements in autoimmune conditions, such as psoriasis and multiple sclerosis, although more rigorous research is needed to establish these effects conclusively.
Long-Term Side Effects of the Carnivore Diet
The fact is that the long-term side effects of a Carnivore Diet are not completely known, as there are no extensive bodies of research conducted focusing on the long-term health impacts of the Carnivore Diet.
However, a 2004 study on the long-term effects of ketogenic diets showed that going on a ketogenic diet for a long period did not cause any significant side effects in the patients, indicating the safety of following a ketogenic diet for a longer period than previously showed [24].
So, you can try this diet under the supervision of a physician or registered dietitian to ensure it won’t negatively affect your health.
Please note that some of the assumed long-term side effects of the Carnivore Diet you may find on the Internet are misconceptions. For example, this diet is thought to cause nutrient deficiencies, which is not true.
You can get the essential nutrients from consuming the foods allowed on the Carnivore Diet. You can also take supplements if necessary after consulting a healthcare professional and taking the required tests.
Some are also concerned about the effect of the Carnivore Diet on cholesterol levels in the long run. You can learn all about the Carnivore Diet and Cholesterol.
To help you decide if a Carnivore Diet is the right choice for you based on your current health status, needs, and goals, I have provided a table summarizing the benefits and side effects of the Carnivore Diet.
Carnivore Diet Benefits
Carnivore Diet Side Effects
Weight Loss, Reduced Inflammation, Improved Gut Microbiome and Digestive Health, Lower Cardiovascular Diseases, Improved Cholesterol Levels, Alleviated Cancer Symptoms, Improved Diabetes, Reduced Symptoms of Autoimmune and Skin Conditions
Brain Fog, Headache, Chills, Muscle Soreness, Sore Throat, Digestive Issues (Diarrhea, Constipation) Dizziness and Irritability, Bad Breath, Bad Taste in the Mouth, Dry Mouth, Cravings, Nausea, Cramping, Rapid Heart Rate, Electrolyte Imbalance
If you still have questions about the side effects of the Carnivore Diet, you can find the recent research results on the effects of low-carb ketogenic diets below.
Generally, no, the Carnivore Diet won’t cause heart problems, but you need to consume saturated fats in moderation and exercise regularly to maintain a healthy heart and body.
Is The Carnivore Diet Bad for Constipation and Diarrhea?
Starting a Carnivore diet, especially if you were previously on a high-carbohydrate diet, may cause temporary digestive issues like constipation and diarrhea in some individuals [25] [26] [27].
"I've been experimenting with the Carnivore Diet. It's been really good for me. I feel fantastic. My energy levels are through the roof."
Does the Carnivore Diet Raise Cholesterol Levels?
Studies show that a ketogenic diet does not negatively impact cholesterol levels in healthy individuals. However, it may negatively impact cholesterol levels in people with a genetic predisposition to cholesterol metabolism dysregulation [28].
The Side Effects of the Carnivore Diet on Kidney and Liver
A 2023 study showed that low-carb ketogenic diets that lead to ketosis by stimulating ketone production can cause serious health problems if the range of ketones exceeds the standard level (3.00mmol/L) during ketosis.
This study suggested that the ketogenic diet's most common and easily reversible consequences include constipation, low-grade acidosis, hypoglycemia, kidney stones, and increased lipid in the blood [29].
However, a 2020 study showed contrary results indicating that 27.7% of patients with mild renal failure experienced normal glomerular filtrate after going on a very low-carbohydrate ketogenic diet for about three months [30].
Another 2020 study indicated that ketogenic diets can be an effective treatment for nonalcoholic fatty liver disease (NAFLD), as following such diets for even six days can significantly reduce the amount of fat in the liver and improve insulin resistance
It happens because the diet increases the breakdown of liver fat and decreases the production of glucose and insulin in the blood. The changes also involve shifting fatty acids towards a process called ketogenesis, which improves the health of the liver's mitochondria (energy producers) and other related processes [31].
Another important point to consider is that a low-carb, high-fat Carnivore Diet may not be a proper option for certain groups of individuals or they need to change their eating habits under the supervision of health experts.
Dr. Jordan Peterson:
"I've experienced significant health improvements on the Carnivore Diet, including better sleep, reduced joint pain, and improved mood stability."
Who Shouldn’t Follow the Carnivore Diet?
Individuals with Certain Health Conditions: People with pre-existing health conditions, such as kidney issues, metabolic disorders, or cardiovascular diseases
Pregnant or Breastfeeding Women
Individuals with Eating Disorders
Those at Risk of Nutrient Deficiencies
People with Gastrointestinal Issues
Children: The safety of the Carnivore Diet for children has not been well-studied. Children have unique nutritional needs for growth and development, so they need to change diets after consulting healthcare professionals.
So, if you’re considering going on a Carnivore Diet, you need to know the foods that can help you avoid or decrease the potential side effects.
The following table summarizes the average calories, protein, fat, sugar, carbohydrates, and vitamins you can receive from the 100 grams of the foods allowed on a Carnivore Diet [32] [33] [34] [35].
All in all, some studies confirm the positive effects of the Carnivore Diet, yet some others prove that there are health concerns related to high-fat diets.
However, no one can say something is good or bad for everyone when it comes to diets and dietary choices. So, what can we do with the Carnivore Diet?
You can consult a healthcare professional to analyze your health status, consider your needs and goals, and give you a personalized plan.