Why Does the Carnivore Diet Cause Constipation? Understanding the Gut Changes

December 2, 2025 •

4 min read

According to anecdotal reports documented by supporters of the diet, some people experience digestive discomfort like constipation during the initial weeks of adopting a carnivore regimen. So, why does the carnivore diet cause constipation for a significant portion of its followers? The answer lies in several key physiological adaptations and nutritional changes that occur in the body.

Quick Summary

Constipation on the carnivore diet stems from multiple factors, including the complete lack of dietary fiber, inadequate hydration, electrolyte imbalances, and temporary shifts in the gut microbiome. While the body can adapt, understanding these causes is key to managing symptoms.

Key Points

Lack of Fiber: The complete absence of dietary fiber on the carnivore diet is the main cause of constipation, as fiber is crucial for adding bulk to stool.
Dehydration is a Risk: Initial water loss from carbohydrate restriction can lead to dehydration, resulting in hard, dry, and difficult-to-pass stools.
Gut Microbiome Changes: The gut's bacterial populations shift without plant-based foods, which can cause temporary digestive disruption and slower transit time.
Electrolyte Imbalance: A loss of electrolytes, particularly magnesium and sodium, can inhibit normal bowel motility and contribute to constipation.
Adaptation Period is Normal: For many, constipation is a temporary side effect that resolves as the body and gut microbiome adapt to digesting a high-fat, high-protein diet.
Fat and Hydration are Key: Ensuring adequate hydration, supplementing electrolytes, and consuming enough animal fat are critical steps for managing bowel regularity.

The Core Cause: Absence of Dietary Fiber

The most significant and frequently cited reason for constipation on the carnivore diet is the complete elimination of dietary fiber. Unlike many standard diets that emphasize plant-based fiber for bulk and regularity, the carnivore approach consists exclusively of animal products, which contain no fiber. Fiber plays a crucial role in maintaining regular bowel movements by adding bulk to the stool and promoting the proper functioning of the intestinal muscles.

When a person transitions to a meat-only diet, the digestive system no longer has this plant-derived bulk to work with. The result is a much smaller amount of fecal matter and, often, a slower digestive transit time, which can feel like constipation. Some proponents of the diet argue that fiber is not necessary for healthy bowel movements and that the body simply produces less waste on a highly digestible, carnivore diet. While bowel movements may naturally become less frequent and smaller, true constipation—characterized by hard stools and straining—is a common initial side effect that requires attention.

The Body's Adaptation Period

The digestive system, including the gut microbiome, needs time to adjust to such a radical dietary shift. In the initial weeks, the gut bacteria that thrive on plant-based fibers die off, while populations that flourish on a diet of fat and protein increase. This shift in bacterial composition can disrupt normal digestive processes, leading to temporary constipation. As the body becomes more efficient at digesting animal products and the gut biome stabilizes, many individuals report that their bowel regularity improves. However, this is not a universal experience.

Crucial Role of Hydration and Electrolytes

Another major contributor to constipation is insufficient hydration and subsequent electrolyte imbalance. When transitioning away from a carbohydrate-heavy diet, the body depletes its glycogen stores. Glycogen is stored with water, so this process releases a significant amount of water and flushes it from the body, alongside essential electrolytes like sodium and potassium.

Dehydration: Without adequate water intake, the colon can pull too much water from the stool, making it hard, dry, and difficult to pass. The need for fluids often increases on a high-protein diet as the body works to process metabolic waste. Therefore, staying well-hydrated is critical to prevent stools from becoming impacted.
Electrolyte Imbalance: Electrolytes play a key role in muscle function, including the peristaltic action that moves waste through the intestines. A deficiency in magnesium, in particular, can be a common cause of constipation, as this mineral has a natural laxative effect. Replacing lost electrolytes, either through increased salt intake or bone broth, is a necessary step.

Optimizing Fat Intake and Digestive Aids

Some individuals on a high-protein, low-fat carnivore diet may also experience constipation. The key is often to ensure a balanced intake of fat relative to protein.

Include Fatty Cuts of Meat: Eating fattier cuts of meat provides the necessary lubrication to aid in smoother bowel movements. Trimming all the fat from your meat can contribute to digestive slowdown.
Consider Organ Meats and Bone Broth: Organ meats can provide a dense source of nutrients that support digestive health. Bone broth, rich in gelatin, can also attract water in the gut, which helps ease the passage of stool.

Comparison: Carnivore Diet vs. High-Fiber Diet

To better understand why constipation can occur, it is helpful to compare the two dietary approaches.


Feature	Carnivore Diet	High-Fiber Diet
Dietary Fiber	Completely absent.	A primary component, rich in sources like fruits, vegetables, and whole grains.
Stool Bulk	Smaller stool volume due to highly digestible foods.	Larger, softer stool volume, making it easier to pass.
Hydration Needs	Increased focus on water and electrolyte intake is critical.	Water is needed, but fiber helps retain moisture in the colon.
Gut Microbiome	Shifts to bacteria that thrive on fat and protein; initially low diversity.	Supports a diverse range of bacteria that feed on plant fibers.
Bowel Transit Time	Often slower due to lack of bulk and adaptation.	Typically faster and more regular.

Practical Solutions for Constipation Relief

If you are experiencing carnivore diet constipation, there are several effective strategies to manage and alleviate symptoms:

Hydrate Adequately: Ensure a high water intake throughout the day. Listen to your body's thirst signals and drink more than you think you need.
Supplement Electrolytes: Add extra salt to your food and consider bone broth, especially during the initial adaptation phase, to replenish lost sodium and other minerals.
Increase Fat Intake: Make sure you are eating enough fat, such as from fatty cuts of meat or by adding tallow or butter. Some individuals find that balancing their protein-to-fat ratio helps a great deal.
Move Your Body: Regular physical activity can help stimulate intestinal movement and improve bowel regularity. Even a brisk walk after meals can make a difference.
Incorporate Magnesium: Consider a magnesium supplement, such as magnesium citrate, which acts as an osmotic laxative and can help soften stools. Consult a healthcare professional before starting any new supplement regimen.
Listen to Your Body: Pay close attention to how different animal foods affect your digestion. Some people may tolerate certain types of meat or fat sources better than others.

Conclusion: Navigating the Adaptation

Carnivore diet constipation is a common, though often temporary, side effect of transitioning to this restrictive eating pattern. It is primarily driven by the absence of dietary fiber, shifts in the gut microbiome, dehydration, and electrolyte imbalances. While proponents of the diet believe the body can adapt to and even thrive on a fiber-free approach, others find these digestive issues to be persistent. By proactively addressing these factors—maintaining optimal hydration, balancing electrolytes, ensuring adequate fat intake, and incorporating physical activity—many individuals can find significant relief. As with any major dietary change, listening to your body's specific needs is the most crucial step towards navigating the transition successfully.

Healthline provides additional information on the risks and challenges associated with the carnivore diet, including digestive issues and potential nutrient deficiencies.

Frequently Asked Questions

Constipation often lasts for the first few days to a few weeks as your body and digestive system, including the gut microbiome, adapt to the new diet. For many, regularity improves over time, though it may be different than before.

Yes, dehydration is a frequent cause of constipation. When you eliminate carbohydrates, your body sheds water stored with glycogen, increasing your fluid needs. Inadequate water intake makes stools harder and more difficult to pass.

Not necessarily, but it is a major contributing factor. The absence of fiber removes the bulk that typically helps form and move stool. While bowel movements may become less frequent, true constipation (straining and hard stools) can occur if other factors like hydration and electrolytes are not properly managed.

To increase fat, you can choose fattier cuts of meat, avoid trimming off natural fats, and add extra sources like butter, ghee, or tallow to your meals. This can help lubricate the digestive tract and promote smoother bowel movements.

Some individuals find relief with magnesium supplements, particularly magnesium citrate, due to its natural laxative properties. Digestive enzymes and bile salts can also be helpful for those struggling to break down fats effectively.

Not always. A highly digestible, fiber-free diet produces less waste, so having fewer bowel movements is normal. True constipation is defined by difficulty passing stools, hard stools, and straining, not just reduced frequency.

Yes, regular physical activity can be highly beneficial. Exercise helps stimulate intestinal muscle contractions (peristalsis), which aids in moving waste through the digestive tract and promoting more regular bowel movements.

Yes, bone broth contains gelatin, which attracts and holds water in the gut. This can help soften stools and aid in more comfortable and regular bowel movements.

Electrolytes like sodium and magnesium are essential for proper muscle contractions, including those in the intestines. An imbalance, common during the early phases of a very low-carb diet, can slow down gut motility and contribute to constipation.