Some individuals may experience short-term side effects of the Carnivore Diet, such as nausea, headache, keto flu, constipation, and diarrhea. These usually go away after a week or two as their bodies adapt to the almost zero-carbohydrate eating plan. 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, and cravings.
Individuals with underlying health issues, pregnant or breastfeeding women, individuals with eating disorders, and those with gastrointestinal problems need to consult a healthcare professional first.
You can eat ruminant meat, poultry, seafood, eggs, and dairy on a Carnivore Diet to get the best results.
What Is the Carnivore Diet?
The Carnivore Diet, the third level of the Primal Diet, is not just a set of eating rules but a lifestyle toward healthy eating that eliminates unnecessary and harmful foods and focuses 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, inducing 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."
However, cutting carbohydrates to less than 5% may cause side effects for some individuals. So, let’s learn about these short-term and long-term effects so we can modify our plans in advance.
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Short-Term Side Effects of the Carnivore Diet
Any major changes in our eating habits affect 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 [2].
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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.
What’s The Cure?
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 keto flu symptoms (headaches, brain fog, dizziness, and irritability).
Stay Hydrated: decreasing carbohydrates to less than 5% a day causes water loss because each gram of carbs contains 3 grams of water. So, you must drink plenty of water to avoid dehydration and its side effects.
Keep Electrolytes Balanced: Consume sodium, magnesium, and potassium to compensate for the lost electrolytes. You can add extra salt to your Carnivore dishes or use electrolyte drinks.
Do Regular Physical Activity: Regular physical activity helps you sweat, which is an effective way to eliminate toxins and naturally rebalance your electrolyte levels.
Similar to the short-term side effects of the Carnivore Diet, there are no detailed studies on its long-term impacts. Anyhow, some conditions are thought to appear after a long time on a ketogenic diet, like the Carnivore Diet.
Long-Term Side Effects of the Carnivore Diet
The long-term side effects of a Carnivore Diet are not completely known, as there is no extensive research focusing on its long-term health impacts.
However, a 2004 study on the long-term effects of ketogenic diets showed that following 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 shown [3].
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 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.
However, the Carnivore Diet may have negative impacts and cause fatigue and less physical endurance.
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Fatigue
A 2020 study on the impacts of ketogenic, low-carb, high-fat (LCHF) diets suggested that they can negatively impact muscle fatigue and physical strength during daily life activities in young and healthy women [4].
Less Physical Endurance
A 2017 study on individuals following a low-carb, high-fat (LCHF) diet showed that although these diets can significantly improve the peak aerobic capacity in endurance athletes, they may disrupt their performance [5].
If you still have questions about the side effects of the Carnivore Diet, you can find the recent research results on the impact of low-carb ketogenic diets below.
Does the Carnivore Diet Cause Heart Problems?
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 [6] [7] [8].
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 [9].
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The Side Effects of the Carnivore Diet on Kidney and Liver
A 2020 study by Ko et al. showed that although protein is necessary for weight loss or glycemic control, high levels of it may cause problems for individuals with severe kidney problems [10].
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 [11].
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 [12].
So, it’s wise to consult your healthcare professional and do regular checkups to see how the diet is working for you.
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 ketogenesis, a process that improves the health of the liver's mitochondria (energy producers) and other related processes [13].
Another essential 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.
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 yet to be well-studied. Children have unique nutritional needs for growth and development, so they must 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.
What to Eat on the Carnivore Diet to Avoid the Side Effects?
The amount of food and portion sizes you eat depends on your needs and goals. You can consult a dietitian, monitor your body’s reactions to different foods, and modify your meal plans accordingly.
Here are the main foods you can consume on a Carnivore Diet to get the best results.
Beef: Various cuts, such as steaks, ground beef, roasts
Pork: Pork chops, pork loin, bacon
Poultry: Chicken, turkey, duck
Fish: Fatty fish like salmon, mackerel, sardines
Seafood: Shellfish such as shrimp, crab, lobster
Organ Meats: Liver, kidney, heart
Eggs
Dairy: Greek Yoghurt, cheese, butter
Bone broth
Animal Fats: Tallow, lard, suet
Salt
Water
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 [14] [15] [16] [17].
All in all, some studies confirm the positive effects of the Carnivore Diet, yet others prove that there are health concerns related to high-fat diets.
However, when it comes to choosing a proper diet, it’s all about your goals, health status, metabolic flexibility, and persistence.
Consult a healthcare professional to analyze your health status, consider your needs and goals, and give you a personalized plan.
Just remember that low-carb ketogenic diets like Carnivore are here to help us create a healthy lifestyle and reach our health and fitness goals. We just need to be smart enough to modify this approach based on our personal needs.
Every week your favorite Carnivore doctors like Dr Chaffee, Dr Baker, Dr Bright join us LIVE to answer your medical questions and our coaches will help you lose weight and heal inflammation fast.
