What Happens If You Only Eat Meat and No Vegetables?

December 18, 2025 •

3 min read

According to research, the vast majority of people following a carnivore diet will likely experience negative health problems. A meat-only diet, which excludes vegetables and other plant-based foods, can lead to severe nutrient deficiencies, digestive issues, and long-term health complications.

Quick Summary

Eating only meat and no vegetables leads to critical nutrient deficiencies, a lack of fiber impacting digestive and gut health, and an elevated risk of heart disease and other chronic illnesses. The diet is difficult to sustain and lacks sufficient long-term research to support its safety.

Key Points

Nutrient Deficiencies: Eliminating vegetables leads to critical shortages of essential nutrients like fiber, vitamin C, potassium, and antioxidants, which are vital for overall health.
Digestive Problems: The complete absence of fiber causes significant digestive issues, including severe constipation, which can lead to other complications like hemorrhoids.
Increased Heart Disease Risk: A high intake of saturated fat and cholesterol from a meat-only diet can elevate LDL ('bad') cholesterol, increasing the risk of cardiovascular disease.
Kidney Strain: The large amount of protein consumed on a carnivore diet puts added stress on the kidneys, raising the risk of kidney stones and impaired function.
Imbalance in Gut Microbiome: The lack of dietary fiber, which feeds beneficial gut bacteria, can lead to gut dysbiosis, increasing susceptibility to inflammation and gastrointestinal disorders.
Higher Cancer Risk: A diet high in red and processed meats, and low in protective plant compounds, is linked to a higher risk of certain cancers, particularly colorectal cancer.
Unsustainable in the Long Term: Due to its extreme restrictiveness and potential for health problems, a meat-only diet is not a sustainable or recommended long-term eating plan.

The Immediate Impact of Eliminating Vegetables

Transitioning to a meat-only diet can lead to rapid weight loss initially, often due to water loss as carbohydrate stores deplete. The absence of fiber from plant foods can initially reduce bloating for some, but commonly results in severe constipation due to reduced stool bulk and slower digestion.

The Nutritional Void: Deficiencies Without Plants

While meat provides protein and some vitamins like B12, eliminating vegetables creates significant nutritional gaps. Key deficiencies include:

Vitamin C: Meat lacks vitamin C, essential for immune function and wound healing. Long-term deficiency can lead to scurvy.
Fiber: Fiber is crucial for digestion, blood sugar, and cholesterol regulation. It is entirely absent in a meat-only diet.
Antioxidants and Phytonutrients: Plants are the primary source of antioxidants and phytonutrients that protect against cellular damage and support health.
Key Minerals: Vegetables provide essential minerals like potassium and magnesium, vital for nerve function and blood pressure. Deficiencies can cause muscle cramps and fatigue.

The Long-Term Health Risks of a Carnivore Diet

A meat-only diet is not scientifically supported as being safe or effective long-term and poses several serious health risks.

Impact on Cardiovascular and Kidney Health

Diets high in saturated fats and cholesterol, common in red and processed meats, can increase LDL cholesterol, raising the risk of heart attack and stroke. High protein intake also strains the kidneys, potentially increasing the risk of kidney stones and worsening existing kidney issues.

Increased Cancer Risk

High consumption of red and processed meats is linked to an increased risk of cancers, particularly colorectal cancer. The lack of protective fiber further contributes to this risk.

Dysbiosis of the Gut Microbiome

Fiber from plants feeds beneficial gut bacteria. Eliminating fiber can disrupt the gut microbiome balance, leading to dysbiosis, increased inflammation, and a higher risk of gastrointestinal disorders.

Omnivore vs. Carnivore: A Nutritional Comparison

Comparing omnivorous and carnivore diets highlights the nutritional consequences of excluding vegetables.


Feature	Omnivorous Diet (Includes Vegetables)	Carnivore Diet (Meat Only)
Nutrient Diversity	High. Provides a wide range of vitamins, minerals, phytonutrients, and fiber.	Low. Lacks many essential nutrients found in plants, including fiber, Vitamin C, and antioxidants.
Fiber Content	High. Supports healthy digestion, gut microbiome, and bowel regularity.	Zero. Can cause severe constipation and disrupt gut health.
Impact on Heart Health	Balanced intake of lean proteins and fiber-rich plants helps manage cholesterol.	Potentially high in saturated fats, raising LDL cholesterol and heart disease risk.
Kidney Strain	Moderate protein intake is generally manageable for healthy kidneys.	High protein load places extra strain, potentially increasing risk of kidney stones and damage.
Cancer Risk	Associated with a lower risk of certain cancers, particularly colorectal cancer.	Linked to an increased risk of colorectal and other cancers due to high red meat and low fiber intake.
Sustainability	Easily sustainable with a variety of enjoyable food options.	Extremely restrictive and challenging to maintain long-term due to limited choices.

Conclusion: The Unsustainability of a Meat-Only Diet

While a carnivore diet may lead to short-term weight loss or blood sugar improvements, often linked to cutting processed carbs, these benefits are outweighed by significant long-term health risks. These risks include severe nutrient deficiencies, heart disease, kidney issues, and digestive problems. Medical and nutrition professionals advise against this restrictive plan, recommending a balanced diet with plant foods for overall health. A diverse diet with both plant and animal sources is best for comprehensive nutrition.

For more information, consult the Harvard School of Public Health resource on vegetables and fruits for nutrition and disease prevention.

Frequently Asked Questions

No, it is highly unlikely to get all essential vitamins without vegetables. While meat contains certain vitamins like B12, it lacks vitamin C, most antioxidants, and several key minerals. Long-term vitamin deficiencies are a significant risk on a meat-only diet.

Some people experience initial weight loss on a meat-only diet due to a reduction in carbohydrate intake and water weight. However, this is not sustainable or healthy in the long term, and the diet comes with numerous health risks.

While some report reduced bloating, a meat-only diet ultimately harms gut health. The complete lack of fiber disrupts the gut microbiome, which can lead to constipation, dysbiosis, and other gastrointestinal problems over time.

Your heart health can be negatively impacted by a carnivore diet. High intake of saturated fats and cholesterol, common in a meat-only diet, can raise LDL cholesterol, a major risk factor for heart disease and stroke.

A very high protein intake, as seen in the carnivore diet, can place significant stress on your kidneys, potentially leading to impaired kidney function or the formation of kidney stones. This is particularly risky for those with pre-existing kidney conditions.

While organ meats provide some vitamins and minerals not found in muscle meat, they do not fully compensate for the complete absence of vegetables. Critical nutrients like fiber and vitamin C remain missing, and the risks of high saturated fat intake persist.

No, the carnivore diet is not considered safe for long-term health by most medical and nutrition professionals. The restrictive nature, lack of fiber, and nutritional deficiencies make it unsustainable and potentially dangerous over extended periods.