Is the Carnivore Diet Bad for Kidney Stones? Find Out!

The carnivore diet is based only on animal-based foods. It consists of animal products such as meat, fish, eggs, and sometimes dairy products like cheese or butter. The carnivore diet can be harmful for people who already have kidney stones. The carnivore diet lacks beneficial nutrients such as fibre and antioxidants. Animal-based foods are high in protein, which increases the risk of the formation of kidney stones, such as uric acid and calcium-based stones. A balanced diet and proper hydration are essential to maintaining kidney health. Let’s discuss in detail why the carnivore diet is not suitable for kidney stones.

What is the Carnivore Diet?

A carnivore diet is a restrictive diet that does not include a variety of foods like fruits, vegetables, grains, legumes, nuts, and seeds. It only includes meat, fish, eggs, and certain dairy products.

Like other low-carb diets, such as keto and paleo, the carnivore diet is high in protein and aims for zero carbohydrates. 

What foods are part of the carnivore diet?

The carnivore diet eliminates all plant foods from it and includes food items such as red meat, beef, chicken, pork, and white fish. 

The pyramid below illustrates the sources of the carnivore diet.

Nutritional Profile of the Carnivore Diet

• High Protein Content: The diet primarily consists of animal meats, which are rich in protein. It helps build muscle and support overall bodily functions.
• Rich in Vitamins: The carnivore diet is also rich in vitamin A, vitamin B12, vitamin E, and vitamin K.
• High Fat: Many types of meat, especially red meat, are high in fat, including saturated fat. It increases calorie intake but also raises concerns about cholesterol and heart health.
• Lack of Plant-Based Foods: The diet eliminates all plant-based foods. Moreover, it lacks essential nutrients like fibre, vitamins, and antioxidants commonly found in fruits, vegetables, grains, and legumes.

Besides its high protein and fat content, the diet also leads to deficiencies in vitamins like C, K, and some B vitamins, as well as minerals like magnesium and potassium. Fibre is also absent, which negatively affects gut health.

Comparison of the Carnivore Diet, Vegetarian Diet, and DASH Diet 

DASH Diet: The DASH Diet (Dietary Approaches to Stop Hypertension) is rich in fruits, vegetables, whole grains, and lean proteins. It is mainly helpful for heart health and reducing blood pressure.

Vegetarian Diet: The vegetarian diet includes plant-based foods, dairy, and eggs. It focuses on nutrient diversity and environmental sustainability.

DASH and vegetarian diets both offer a more balanced nutritional profile, rich in fibre, antioxidants, and micronutrients as compared to the more restrictive carnivore diet.

The below table also highlights the difference between the carnivore diet, vegetarian diet, and DASH diet.

Aspect	Carnivore Diet	DASH Diet	Vegetarian Diet
Food Sources of Diet	Animal products (meat, fish, eggs)	Fruits, vegetables, whole grains, lean proteins	Plant-based foods, also include dairy and eggs
Macronutrients	High protein, high fat	Balanced (carbs, protein, healthy fats)	High in carbohydrates, fiber, moderate protein
Does not include	All plant-based foods (intake of fruits, vegetables, grains, legumes)	Excess salty foods, sugar, red meat, processed foods	Meat and fish (in strict forms), processed foods
Nutritional Benefits	High in protein and fat	Rich in fiber, vitamins, minerals, and antioxidants	Rich in fiber, vitamins, and minerals, low in saturated fat
Nutrient Deficiencies	Lacks fiber, vitamins (C, K), and minerals (potassium, magnesium)	None if balanced properly	Potential deficiency in vitamin B12, iron, omega-3 if not supplemented
Health Risks	Long-term heart disease, digestive issues and nutrient deficiencies	Lowers blood pressure, and reduces heart disease risk	Reduces risk of heart disease, stroke, and cancer

The Relationship Between Diet and Kidney Stones

What are Kidney Stones?

Kidney stones, also called renal calculi or nephrolithiasis, are brittle masses formed from crystals. Stones in the kidney are dense deposits of minerals and salts that result in kidney pain and urine blockage.

Urine also contains some minerals, acids, and substances, like calcium from foods, sodium, oxalate, and uric acid. When the urine contains excess particles of these substances, it sticks together to form a crystal or stones. 

What Causes the Formation of Kidney Stones?

• The causes of kidney stone formation include improper diet, excessive body weight, and some medical conditions. Other diseases also increase the risk of the formation of kidney stones, such as primary hyperparathyroidism, obesity, gout, and diabetes.

Role of Diet in Stone Formation

• The diet also contributes to the formation of kidney stones. Certain factors can lead to the formation of kidney stones.
• High sodium intake: High sodium increases the amount of calcium (hypercalciuria) in the urine, which causes the formation of kidney stones. Calcium oxalate stones are the most common type of calcium-based stone due to their high sodium intake. Foods such as processed foods, condiments, and meats are higher in sodium.
  

• High Protein Diet: Consuming too much animal protein intake, including red meat, poultry, eggs, and seafood (a carnivore diet), causes kidney stones. A diet high in protein raises the amount of calcium, oxalate, and uric acid that the body flushes out. This can cause calcium oxalate and uric acid kidney stones to form.
• Oxalates: Foods that are high in oxalates include chocolates, spinach, rhubarb, and nut products. Oxalates are a byproduct of certain foods that bind calcium in the urine and cause the formation of kidney stones.
• Vitamin C: Vitamin C is a water-soluble vitamin that includes citrus fruits, peppers, kiwifruit, strawberries, and broccoli. The body converts a high dietary intake of vitamin C foods and supplements into oxalates, increasing the risk of oxalate stones.

How Does a High-Protein Intake Affect Kidney Health?

High protein intake directly affects kidney health and causes the formation of kidney stones.

How does a high-protein diet increase uric acid and kidney stone formation?

Protein-rich diets, particularly those derived from animal sources, elevate uric acid levels. In people with other comorbidities such as kidney disease or gout, excessive protein intake can lead to high levels of uric acid and increase the risk of kidney stones. 

Continuous high levels of uric acid contribute to kidney damage and cause crystal deposition in the kidneys. It leads to inflammation and improper kidney function.

How Do Low Citrate Levels Contribute to Kidney Stone Formation?

High protein intake from animal sources results in low citrate levels in the urine. Citrate helps prevent kidney stones by binding to calcium, making it less likely to form stones. When citrate levels are low, calcium binds with oxalate or phosphate, leading to stone formation.

What is hyperfiltration, and how does it cause kidney stones?

As protein intake increases, the kidneys experience a higher GFR, which is an adaptive response. A high-protein diet increases the glomerular filtration rate (GFR), leading to hyperfiltration, where the kidneys have to work harder to remove these byproducts. Chronic hyperfiltration can contribute to kidney function decline. However, chronic hyperfiltration can lead to glomerular damage and worsen normal kidney functions over time, which also increases the risk of chronic kidney disease (CKD).

Similarly, high protein also increases the excretion of calcium in the urine (hypercalciuria). It is another risk factor for calcium-based kidney stones. This occurs because dietary protein increases calcium resorption from the bone, enhances calcium loss through urine, and also worsens bone health.

Types of Kidney Stones and Causes

Kidney stones are of four types. Each type varies in size, shape and color.

• Calcium-based stones (including calcium-oxalate stones)
• Struvite stones
• Uric acid stones
• Cystine stones
  
  

  Calcium-Based Stones: 

Calcium stones, such as calcium oxalate, are the most common type of kidney stones. They form when calcium combines with oxalates in the urine. Inadequate calcium and fluid intake, along with other conditions, may contribute to the formation of calcium oxalate stones.

Fruits, vegetables, nuts, legumes, grains, and seeds naturally contain oxalates. Some foods, such as peanuts, rhubarb, spinach, beets, and sweet potatoes, are high in oxalates.

People with calcium oxalate stones are advised to limit high-oxalate foods to reduce the risk of stone formation. Adequate calcium intake is recommended for most people with kidney stones because calcium binds with oxalates in the gut, reducing their absorption into the bloodstream. It is also important to limit sodium, as high sodium levels can increase calcium excretion in the urine, contributing to stone formation. Pairing calcium-rich foods with high-oxalate foods is helpful to reduce the risk of kidney stones.

According to the National Kidney Foundation, a person should not consume calcium more than 1000-1200 mg per day (3 servings per meal) to prevent kidney stone formation. 

Similarly, the intake of high-sodium foods increases the amount of calcium in the urine because sodium and calcium share the same transport in the kidney. Therefore, eating a lot of sodium may also cause another stone in the kidney. 

How to Avoid Calcium Oxalate Stones?

To avoid calcium oxalate stones, it is advised to restrict foods such as the carnivore diet (rich in animal protein), sugary drinks, and foods high in oxalates. Lowering sodium also helps to control blood pressure and prevent the formation of kidney stones. 

Uric Acid Stones:

Uric acid stones are also another common type of kidney stone that usually run in families. Men more commonly develop these types of stones, usually due to a high intake of animal protein or inadequate water intake. They are also more common in chemotherapy patients, who have gout or have a family history of kidney stones.

Foods like organ meats and shellfish contain high amounts of purines, a naturally occurring chemical component. Consuming a lot of purines in the diet increases the formation of monosodium urate, which can cause kidney stones in some circumstances. 

High purines in the diet cause the kidneys to produce more uric acid and have a greater acid burden to eliminate. Urine becomes more acidic when uric acid excretion increases. Uric acid stones are more likely to form because of the high acidic content of the urine.

How to Avoid Uric Acid Stones?

Experts recommend sticking to a nutritious diet primarily consisting of fruits and vegetables, whole grains, and low-fat dairy products.

• To avoid uric acid stones, people should restrict foods high in purines, such as red meat, organ meat, beer, and other alcoholic beverages; meat-based gravies; sardines; and shellfish.
• Limit beverages and meals that contain added sugar, especially high fructose corn syrup. 
• Avoid short-term diets and limit alcohol consumption, as it can raise blood uric acid levels. 

Eating more fruits and vegetables and reducing animal-based proteins helps lower urine acidity, which may lower the risk of uric acid stones.

Struvite Stones:

Struvite stones are a less common and rare type of kidney stone. An infection in the upper urinary tract causes it to form more frequently in women than in men. These stones often grow quickly and usually fill the entire kidney. If left untreated, these stones can lead to frequent infections, loss of kidney functions, and renal failure. 

Cystine Stones:

Cystine stones are usually larger than other kidney stones and tend to recur. It results from a hereditary genetic disorder called cystinuria. Excessive levels of the amino acid cysteine, which appears in the urine, cause it. These types of stones usually form in the kidneys, bladder, and ureters (which carry urine from the kidneys to the bladder). The most important lifestyle modification to prevent cystine stones is to drink plenty of water.

Impact of the Carnivore Diet on Kidney Health

High Protein Intake and Its Effects

The carnivore diet is based on animal-based foods that are high in protein. The body breaks down large amounts of protein into various byproducts. It significantly impacts kidney health in the following ways.

Uric Acid Production: A high-protein diet rich in purine-containing meats leads to increased production of uric acid. The excess uric acid contributes to the formation of kidney stones, especially uric acid stones.

Calcium Excretion: High protein intake can lead to hypercalciuria (increased calcium levels). It directly affects bone health and causes the formation of calcium oxalate stones (the most common type of kidney stone). High calcium levels also increase the workload on the kidneys to filter and balance mineral levels in the body.

Does the Carnivore Diet Increase the Risk of Kidney Stones?

The carnivore diet (high protein intake from animal sources) increases the risk of kidney stones, especially in people with already compromised kidneys. The carnivore diet increases the risk of the formation of kidney stones in the following ways:.

• The high protein intake in the carnivore diet makes the urine acidic, resulting in the kidneys excreting uric acid. Acidic urine results in the formation of kidney stones, such as uric acid stones. 
• The carnivore diet does not include plant-based sources, which leads to a decrease in protective compounds such as citrate, which increases the risk of kidney stones. Without citrate from plant foods, the risk of stone formation increases, especially calcium oxalate stones.
• People with a history of kidney stones, chronic kidney disease (CKD), or conditions like gout (linked to high uric acid levels) are at higher risk of forming kidney stones with a carnivore diet.

The role of hydration in preventing kidney stones

Adequate hydration is necessary to prevent kidney stones, especially on high-protein diets like the carnivore diet. Drinking sufficient water helps flush out waste products and reduces the concentration of stone-forming substances, such as urea and oxalates. 

What is the recommended amount of fluid in a high-protein diet?

People on a high-protein diet should drink 2-3 litres (8-12 cups) of water per day. However, the exact requirements for fluids depend on activity levels and individual needs.

Why is diluted urine essential to prevent the formation of kidney stones?

The diluted urine reduces the concentration of minerals and salts that form hard deposits in the kidneys. However, the fluid requirement depends on the individual's health. Sufficient intake of water prevents the formation of kidney stones through diluted urine. 

However, concentrated urine causes the crystallisation of waste products like calcium, oxalate, and uric acid, increasing the risk of stone formation. Drinking enough water ensures that the urine stays diluted and reduces the chances of stone formation.

How Does Citric Acid Prevent Kidney Stones?

Lemons and other citrus fruits contain citric acid, which protects against kidney stones. It binds calcium and oxalates in the urine, which prevents it from forming kidney stones. For example, lemons are a natural diuretic that helps the body to excrete excess water and salt. The lemon water is a natural source of citric acid that increases urinary citrate levels. It lowers the risk of forming calcium oxalate stones. Combining lemon water with a high-protein diet effectively reduces the risk of stone formation associated with the carnivore diet.

Comparative analysis of diets and kidney stones

Carnivore Diet vs. DASH Diet: Kidney Stone Risk

The DASH diet (Dietary Approaches to Stop Hypertension) includes healthy foods like fruits, vegetables, whole grains, and low-fat dairy and limits salts, added sugars, and saturated fats. It is beneficial for reducing the risk of kidney stones as compared to the carnivore diet, which may increase stone risk due to high meat consumption and acidic urine. The below table highlights the comparative analysis of both diets.

Primary Role	Carnivore Diet	DASH Diet
Main Focus	High in animal-based foods such as red meat	Also involves plant-based nutrition, fruits, vegetables, and low-fat dairy
Meat Consumption	High (Red meat, poultry, fish)	Limited, lean meats in moderation
Plant-Based Foods	Excludes all plant-based foods	Rich in fruits, vegetables, whole grains
Nutrient Profile	High protein, low carbohydrate	Balanced in protein, carbs, and healthy fats
Calcium and Oxalate Balance	May increase calcium loss through urine, increasing stone risk	Promotes calcium absorption with lower oxalate intake
Effect on Urine pH	This can lead to more acidic urine	Diluted urine (helps maintain neutral to alkaline urine)
Risk of Kidney Stones	The risk of forming kidney stones is higher due to excessive protein consumption and acidic urine	Lower risk of kidney stones due toa  balanced diet, plant-based foods, and hydration
Hydration & Fluid Intake	Hydration should be proper, but high protein may dehydrate	Promotes high fluid intake and reduces stone formation
Vegetarian Diet Influence	Excludes all plant-based foods	Linked with lower kidney stone risk
Overall Kidney Health	May strain kidneys with excess protein	Supports kidney health through nutrient diversity

How saturated fats contribute to kidney stone formation

A high intake of saturated fats can contribute to kidney stone formation by increasing the levels of calcium and oxalate in the urine. Saturated fats, normally found in animal products like red meat, full-fat dairy, and processed foods, can contribute to inflammation and increase the risk of urinary stone formation. When consumed in excess (especially in a carnivore diet), it increases calcium excretion and acid, which increases the risk of kidney stones.

Several studies have shown that diets high in animal proteins, such as red meat, increase the chances of kidney stones. Meat consumption increases the excretion of calcium, uric acid, and oxalates in urine, which form crystals and result in stone formation. Specifically, the consumption of red meat and other animal-based proteins is associated with elevated uric acid levels, which in turn lead to the formation of kidney stones. 

Benefits of Reducing Saturated Fats Through Balanced Diets

Reducing saturated fat intake is beneficial to lower the risk of kidney stone formation. A balanced diet, with a lower intake of animal fats and processed foods, maintains a healthy balance of nutrients in the body. It prevents the excessive excretion of substances like calcium and oxalate in the urine. A diet rich in fruits, vegetables, whole grains, and plant-based foods improves kidney health by reducing inflammation due to its high potassium, fibre, and low oxalate content. It helps in preventing kidney stone formation.

The NIH highlighted that vegetarian and balanced diets reduce the risk of kidney stones. Studies have found that plant-based diets are lower in saturated fats and higher in potassium, magnesium, and fibre, which helps prevent kidney stones. 

Additionally, vegetarian diets are often lower in animal proteins, which reduces the risk of stone formation. Balanced diets rich in plant-based foods also improve kidney function. It decreases stone formation and maintains overall kidney health through proper hydration and reduced urinary acidity.

Is the Carnivore Diet Safe for Kidneys?

The carnivore diet is becoming famous and gaining popularity due to its benefits, such as weight loss, management of autoimmune diseases, and improved insulin sensitivity. However, it is not safe for everyone, especially for those with certain health conditions. 

Risks for Individuals with Pre-Existing Conditions

The carnivore diet is not safe for people with the following conditions.

• Chronic Kidney Disease (CKD): People with CKD or a family history of kidney disease experience a decline of kidney function. Following the carnivore diet further worsens the complications.
• Genetic Predispositions: People with genetic conditions such as hypercholesterolaemia (high cholesterol) or others such as CVD increase the risk of heart disease. The carnivore diet lacks fibre, fruits, and vegetables, which negatively impacts the heart.
• Gastrointestinal Issues: The absence of fibre in the Carnivore Diet may lead to digestive problems like constipation or gut microbiome imbalances. Those with irritable bowel syndrome (IBS) or other digestive disorders may experience worsened symptoms.

So, it is advised to consult a healthcare professional or registered dietitian to make a customised meal plan depending on your personal health and genetic predispositions. Regular health monitoring, such as blood pressure, cholesterol, kidney functions, and overall nutrients, helps preserve kidney health. Similarly, slow diet transitions and incorporating a balanced variety of foods help lower the complications of kidney stones and prevent their formation.

Can High-Protein Diets Be Balanced?

Although high-protein diets, like the carnivore diet, carry risks, they can be balanced with proper strategies, such as moderation in protein intake and increased hydration, to reduce potential health risks. You can balance a high-protein diet in the following ways:

• Hydration: Increased protein intake requires more water to help the kidneys flush out waste products like urea. Staying well-hydrated is important to lower kidney strain.
• Moderation: While the Carnivore Diet focuses on animal products, moderation is necessary. Consuming lean meats and varying the protein sources (e.g., fish, poultry, eggs) can help avoid excessive saturated fats that increase cholesterol levels.
• • Supplemental nutrients: high-protein diets are often low in certain vitamins and minerals, especially fibre, vitamin C, and magnesium. Using these supplements and consuming plant-based foods can help avoid nutrient deficiencies.

Recommendations for Kidney Stone Prevention

These are some general dietary guidelines for individuals who are at higher risk of kidney stones.

• Drink a sufficient amount of water: It is recommended to drink water up to 3-4 liters per day depending on body size, climate, and physical activity. It includes any type of fluid, like water, coffee, and lemonade. It shows beneficial effects except for grapefruit juice and soda. Sufficient intake of water also produces diluted urine and excretes about 2.5 L/day.
• Limit high-oxalate foods: Many foods, such as spinach, berries, chocolate, wheat bran, nuts, beets, tea, and rhubarb, are high in oxalates and should be restricted from the diet to prevent the formation of kidney stones.
• Consume sufficient dietary calcium: It is recommended to consume three servings of dairy per day to lower the risk of calcium stone formation.
• • Avoid taking extra calcium supplements: Your body can better tolerate calcium from food sources. So, people with a history of calcium stones should avoid excess calcium supplementation as recommended by a physician or registered kidney dietitian.
• Eat a moderate amount of protein: High protein intake is harmful to the kidneys and excretes more calcium, causing more formation of stones in the kidney. Therefore, doctors recommend consuming a moderate amount of protein to meet your body's requirements. 
• Avoid foods that are high in salt: High sodium increases calcium in the urine, increasing the risk of developing kidney stones. Therefore, experts recommend following a low-salt diet to regulate blood pressure and avoid kidney stones.
• Avoid high doses of vitamin C supplements: The US Dietary Reference Intake recommends 60 mg of vitamin C daily. The high dose of vitamin C (more than 1000 mg/day) has been shown to increase oxalate levels in some individuals, which increases the risk of kidney stones. 

Frequently Asked Questions

Can the carnivore diet reduce kidney stone recurrence?

Experts advise limiting animal protein to prevent kidney stone recurrence. Consuming a carnivore diet (rich in animal protein) increases the chances of forming kidney stones.

What are the safest high-protein options for kidney health?

As compared to animal protein, plant-based protein is the safest option to consume. Foods such as lentils, chickpeas, legumes, beans, nuts, and tofu are safer for kidney health than meat and dairy products.

What is the role of hydration in preventing kidney stones on the carnivore diet?

Hydration is important in the prevention of kidney stones. Drinking sufficient fluids dilutes the urine, which reduces the risk of stone formation.

How does animal protein contribute to kidney stone formation?

High intake of protein can increase the risk of kidney stones by increasing the amount of calcium, oxalate, and uric acid in the urine. It results in the formation of calcium oxalate and uric acid stones. 

What are alternative diets for kidney stone patients?

For kidney stone patients, a healthy diet includes a high intake of fruits, vegetables, and whole grains, with limited animal protein and processed foods. It also includes limiting sodium and sugar and drinking sufficient fluids.

Can I prevent kidney stones on a high-protein diet?

No, it is not possible to prevent kidney stones on a high-protein diet. The high-protein diet puts a strain on the kidneys and increases the risk of kidney stones. 

What are low-oxalate foods?

Kidney stone patients are recommended to consume low-oxalate foods such as dairy, fruits, vegetables, grains, herbs, and spices.

What type of diet reduces kidney stone risk?

People should consume kidney-friendly foods to lower the risk of kidney stones. A diet that reduces the risk of kidney stones includes consuming sufficient fluids, taking a calcium diet (calcium-rich foods), and limiting animal protein and sodium.

Are carnivore diets bad for your kidneys?

The carnivore diet may increase the risk of kidney issues, especially in individuals with pre-existing kidney conditions or those who consume excessive protein over time.