What is the carnivore diet one meal per day? Understanding This Eating Pattern

October 5, 2025 •

3 min read

According to a 2021 study involving over 2,000 participants, those following a carnivore diet reported improvements in various health markers, though this survey-based research should be interpreted with caution. This article explores the combined practice of the carnivore diet one meal per day, detailing its structure, underlying rationale, and critical health implications.

Quick Summary

The carnivore diet one meal per day (OMAD) is a restrictive eating plan combining an all-animal-products diet with intermittent fasting. It eliminates plant-based foods, consolidating daily calories into one large meal, and is often used for weight loss and inflammation reduction, but carries risks like nutrient deficiencies and digestive issues.

Key Points

Extremely Restrictive: The carnivore OMAD diet combines an all-animal-product diet with a 23-hour daily fasting period.
High Risk of Nutrient Deficiencies: By eliminating plant-based foods, the diet severely lacks fiber, Vitamin C, magnesium, and other essential nutrients.
Potential for Digestive Issues: The complete absence of fiber can disrupt gut health, leading to constipation and other long-term digestive problems.
Cardiovascular Concerns: High intake of red and processed meats, often a staple of this diet, raises concerns about increased saturated fat, cholesterol, and risk of heart disease.
Sustainability is Challenging: The strict nature of the diet makes it difficult to maintain for extended periods, and there is a high likelihood of rebound weight gain.
Scientific Evidence is Limited: The claims of benefits are largely based on anecdotal reports rather than controlled, long-term scientific studies.

Understanding the Carnivore Diet and OMAD

The carnivore diet one meal per day combines two highly restrictive eating methods: the carnivore diet and the One Meal a Day (OMAD) fasting schedule. The carnivore diet permits only animal products like meat, fish, eggs, and certain low-lactose dairy. It strictly excludes all plant foods. OMAD is a type of intermittent fasting where all food is eaten within a single window, usually about an hour, with only calorie-free drinks allowed otherwise. This combination means fasting for around 23 hours and then eating one large, meat-based meal.

The Mechanisms Behind Carnivore OMAD

Supporters of this diet believe it enhances the effects of each individual approach. Eliminating carbohydrates puts the body into ketosis, burning fat instead of glucose. The high protein and fat keep people feeling full, potentially making the OMAD fasting period easier. The diet's strictness is also thought to reduce inflammation from certain plant foods. Advocates claim this leads to faster weight loss, better blood sugar control, and less inflammation.

Potential Benefits and Significant Risks

Though some short-term benefits and personal accounts exist, most experts warn against this diet's long-term feasibility and safety. Its extreme limitations pose many health challenges.

Nutrient Deficiencies and Gut Health

A major concern is the severe lack of key nutrients. The strict carnivore diet, especially once a day, removes all fiber, essential for digestion and a healthy gut. This can cause constipation and lasting gut problems. Many vitamins and minerals found mostly in plants, like Vitamin C, magnesium, and potassium, are missing or at low levels. While some suggest organ meats and varied animal products can help, reaching ideal nutrient levels without supplements or medical advice is challenging.

Heart Disease and Cancer Risk

Eating large amounts of red meat, with its high saturated fat and cholesterol, is a significant health risk. Many health bodies advise limiting red meat, though views on saturated fat and heart disease vary. High fat intake combined with OMAD, which can affect blood pressure and cholesterol, increases cardiovascular risks. A strong link also exists between eating a lot of red and processed meats and higher risks of certain cancers, especially colorectal cancer.

Strain on Kidneys and Potential for Disordered Eating

The high protein can stress the kidneys, particularly for those with existing kidney issues. Long fasting periods and a very limited food list can also raise the risk of developing disordered eating, such as overeating during the single meal. The diet's extreme nature makes it very hard for most people to stick to long-term.

A Sample Carnivore OMAD Meal and Its Considerations

An example meal could include steak, organ meats, butter, and eggs, along with water and electrolytes.

Comparing Carnivore OMAD vs. Balanced Intermittent Fasting


Aspect	Carnivore OMAD	Balanced OMAD (e.g., Mediterranean diet foods)
Dietary Variety	Extremely limited (animal products only)	High variety (fruits, vegetables, whole grains, lean protein, healthy fats)
Nutrient Completeness	High risk of deficiencies (fiber, Vitamin C, potassium, magnesium)	Generally provides a broad spectrum of nutrients
Weight Loss Potential	Possible short-term results due to high satiety and calorie restriction	Effective and more sustainable with fewer nutritional risks
Health Risks	Increased risk of heart disease, cancer, kidney issues, and gut problems	Associated with reduced risk of chronic diseases
Sustainability	Very difficult to maintain long-term due to restrictiveness and cravings	Easier to sustain due to dietary flexibility and enjoyment
Gut Microbiome	Negatively impacted due to lack of fiber	Supports a diverse and healthy gut microbiome
Scientific Backing	Largely anecdotal, lacks robust long-term research	Supported by extensive clinical research and long-term studies

Conclusion: Approach with Extreme Caution

Combining the carnivore diet and OMAD is a highly restrictive approach. While some report success, especially with weight loss and inflammation, the lack of strong scientific backing and significant risks make it questionable for long-term health. The risk of serious nutrient deficiencies, heart problems, and digestive issues is high. For most individuals, a more balanced diet with intermittent fasting is a safer and more effective way to reach health goals. Always speak with a healthcare provider or registered dietitian before trying such a strict diet, especially if you have existing health conditions. For general nutrition advice, the {Link: American Heart Association https://www.heart.org/en/healthy-living/healthy-eating}.

Frequently Asked Questions

The carnivore diet one meal per day is considered risky due to its restrictive nature and potential for nutrient deficiencies, digestive issues, and long-term health problems. It is not recommended for individuals who are pregnant, nursing, have kidney or heart disease, or a history of disordered eating.

Only animal products are permitted. This includes various types of meat (beef, pork, lamb, poultry), fish, seafood, eggs, and some low-lactose dairy products like butter and heavy cream. All plant-based foods are excluded.

Weight loss is possible in the short term, primarily due to the severe calorie restriction and high satiety from fat and protein. However, the diet's unsustainability means weight is often regained once regular eating resumes.

The most common deficiencies include dietary fiber, Vitamin C, magnesium, potassium, and beneficial plant compounds and antioxidants, all of which are essential for overall health.

The complete lack of fiber, a crucial nutrient for gut bacteria, can lead to a less diverse and potentially unhealthy gut microbiome. This can negatively impact digestion, immunity, and overall well-being.

For some individuals, especially those with diabetes or insulin sensitivity, concentrating all food intake into a single meal can cause significant fluctuations in blood sugar. Fasting periods can also cause dips or spikes.

High-quality, long-term research on the carnivore diet is very limited. Most positive claims are based on anecdotal evidence, while many health professionals express significant concerns over its risks.

While meat does contain small amounts of Vitamin C, the quantities are insufficient to meet daily requirements. The theory that the body needs less Vitamin C on a low-carb diet is not conclusively proven, and deficiencies remain a risk.