What is the 80 percent carnivore diet?

December 5, 2025 •

4 min read

Arctic populations have survived for generations on nearly entirely animal-based diets. The 80 percent carnivore diet, a variation of this restrictive eating style, focuses on consuming 80% of daily calories from fat and 20% from protein, a strategy designed to promote ketosis without any carbohydrates.

Quick Summary

The 80 percent carnivore diet is a high-fat, ketogenic-style variation where 80% of calories are from fat and 20% from protein, exclusively from animal products. The macronutrient ratio helps sustain ketosis and energy while restricting protein. Followers report benefits like weight loss and mental clarity, though risks like nutrient deficiencies exist.

Key Points

High-Fat Macronutrient Ratio: The diet is defined by getting approximately 80% of your daily calories from fat and 20% from protein, exclusively from animal sources.
Supports Ketosis: The high fat-to-protein ratio helps maintain ketosis, a metabolic state where the body burns fat for fuel instead of glucose from carbohydrates.
Strictly Animal-Based: All plant-based foods, including fruits, vegetables, grains, and legumes, are completely excluded from the diet.
Focus on Fatty Meats: Followers prioritize fatty cuts of meat like ribeye, pork belly, and 80/20 ground beef to meet the high fat intake requirement.
Potential for Nutrient Gaps: The exclusion of all plant foods can lead to deficiencies in fiber, certain vitamins (like Vitamin C), and minerals, raising potential health concerns.
Anecdotal Benefits, Limited Research: While anecdotal evidence suggests benefits like weight loss and mental clarity, high-quality, long-term scientific research on the specific 80/20 carnivore diet is limited.

Understanding the 80 Percent Carnivore Diet

Unlike the strict, all-meat carnivore diet, the 80 percent carnivore diet is a high-fat approach based on macronutrient ratios. The core principle involves structuring your intake so that approximately 80% of your daily calories come from animal fats and the remaining 20% from protein, with carbohydrates entirely excluded. This approach is favored by some who believe it optimizes fat-burning (ketosis) while ensuring adequate, but not excessive, protein intake.

The Macronutrient Breakdown

To achieve the 80/20 calorie split, one must intentionally select fattier cuts of meat and supplement with pure animal fats. While protein provides 4 calories per gram and fat offers 9 calories per gram, the actual ratio by weight is closer to 1:1, meaning you'll be eating roughly equal amounts of fat and protein. This focus on high-fat consumption is central to the diet's effectiveness, as it provides a dense, sustained energy source and promotes satiety, helping to reduce overall calorie intake naturally.

Allowed and Excluded Foods

The food list for the 80% carnivore diet is simple and restrictive, focusing solely on animal products. The goal is to maximize fat intake while avoiding all plant-based foods.

Allowed Foods:

Fatty Cuts of Meat: Ribeye, beef brisket, pork belly, and 80/20 ground beef are staples.
Fatty Fish: Salmon, mackerel, and anchovies provide essential omega-3 fatty acids.
Other Animal Products: Eggs, bone marrow, bone broth, and organ meats like liver.
Animal Fats: Tallow, lard, and grass-fed butter are used for cooking and added to meals.
Low-Lactose Dairy (in moderation): Hard cheeses and heavy cream can be included but may be limited by some due to lactose content.

Excluded Foods:

All Plant Foods: This includes fruits, vegetables, legumes, nuts, and seeds.
Grains and Sugar: Bread, pasta, and all processed sugars are off-limits.
High-Lactose Dairy: Milk and yogurt are typically avoided due to higher sugar content.

How to Implement the 80/20 Rule

Achieving the macronutrient goal requires deliberate food choices and sometimes macro tracking. Here’s a practical guide:

Prioritize Fatty Meats: Instead of lean chicken breast, opt for chicken thighs with skin or fatty cuts of beef. Always choose the fattiest ground beef available, such as 80/20 or even 70/30.
Use Added Fats: Cook your meats in generous amounts of beef tallow or grass-fed butter. Drizzle melted butter over cooked steaks or mix lard into ground beef patties to increase the fat content.
Incorporate Eggs: Eggs are a versatile source of fat and protein. Consider eating whole eggs scrambled in butter or cooked in tallow.
Track Your Macros (Initially): In the beginning, using an app to track your food intake for a few days can help you understand what an 80/20 ratio looks like in practice. This makes it easier to eyeball portions later on.

Benefits and Risks of the 80 Percent Carnivore Diet

While anecdotal reports of the carnivore diet are plentiful, scientific research on the specific 80/20 variation is limited.

Potential Benefits:

Weight Loss: High protein and fat content promote satiety, which can lead to reduced calorie consumption and weight loss.
Mental Clarity: Supporters report enhanced cognitive function and reduced 'brain fog', possibly due to stable blood sugar levels associated with ketosis.
Reduced Inflammation: Eliminating processed foods and many plant-based compounds may lead to a reduction in systemic inflammation for some individuals.

Potential Risks:

Nutrient Deficiencies: Excluding plant foods eliminates dietary fiber and many essential vitamins and minerals like Vitamin C, Vitamin E, and potassium. Organ meats are sometimes used to mitigate this, but it can be a significant concern.
Digestive Issues: The complete lack of fiber often leads to constipation and can negatively impact gut microbiome health.
High Cholesterol: High intake of saturated fat may raise LDL cholesterol levels, though the long-term health implications are debated.

80/20 Carnivore vs. Standard Carnivore


Feature	80 Percent Carnivore Diet	Standard Carnivore Diet
Macronutrient Ratio	High-fat, fixed at 80% calories from fat and 20% from protein.	Variable. Can range from high-fat to high-protein depending on food choices.
Primary Goal	Sustain a deep state of ketosis by optimizing the fat-to-protein ratio.	Eliminate plant foods to address perceived sensitivities and autoimmune issues.
Emphasis	Deliberately choosing fatty cuts and adding pure fats (tallow, butter).	Eating any animal product until satisfied, with less emphasis on macro proportions.
Common Cuts	Ribeye, pork belly, 80/20 ground beef.	Broader range, including leaner meats like chicken breast.

Conclusion: Is the 80 Percent Carnivore Diet Right for You?

The 80 percent carnivore diet is a specialized, high-fat version of the carnivore diet aimed at maximizing ketosis. While it may offer benefits such as weight loss and enhanced mental clarity for some, its highly restrictive nature presents notable risks, including potential nutrient deficiencies and digestive issues due to a complete lack of fiber. As with any highly restrictive diet, it is not sustainable for everyone and may be unsafe for certain populations. It is crucial to consult with a healthcare professional before beginning to ensure it aligns with your health needs and goals. For more context on metabolic health and low-carb eating, explore resources like those available at Virta Health.

Frequently Asked Questions

The main difference is the emphasis on macronutrient ratios. The 80% version specifically aims for a caloric split of 80% fat and 20% protein to drive ketosis, whereas the standard carnivore diet simply involves eating only animal products without a strict macro focus.

Key food sources include fatty cuts of meat (ribeye, ground beef), animal fats (tallow, lard, butter), fatty fish (salmon), and eggs. Some followers also include low-lactose dairy like hard cheeses and heavy cream in moderation.

No, the diet strictly excludes all plant-based foods, including fruits, vegetables, grains, legumes, and nuts. This is to maintain a carbohydrate-free intake and keep the body in a ketogenic state.

Some individuals report weight loss due to the high satiety from fat and protein, which can lead to reduced overall calorie intake. The ketogenic state also promotes fat burning. However, results can vary, and more research is needed.

The long-term safety of this highly restrictive diet is a concern among nutrition experts. Risks include nutrient deficiencies, high intake of saturated fat, and lack of fiber, which can affect gut health. Consultation with a healthcare provider is recommended.

You can achieve the ratio by prioritizing fatty cuts of meat and adding extra animal fats like tallow or butter to meals. Initially, tracking your macros with an app can help ensure you're hitting the targets correctly.

Excess protein can be converted into glucose through a process called gluconeogenesis, which could potentially pull your body out of ketosis, thereby altering the diet's intended metabolic state.