Review of Carnivore Diet Effects
A recent review published in Nutrients assessed the nutritional adequacy and health effects associated with the carnivore diet (CD). The CD is characterized by consuming minimally processed animal-based foods, including fish, meat, eggs, seafood, animal fats, and full-fat dairy, making it a low-carbohydrate/high-fat dietary pattern.
Claimed Benefits and Associated Risks
Proponents of the CD claim benefits such as weight reduction, improved physical and cognitive performance, and a reduced risk of chronic conditions like diabetes, dyslipidemia, hypertension, and gastrointestinal disorders. These claims are often attributed to avoiding antinutritional compounds present in plant-based foods.
However, the absence of plant-based foods in the CD also means a lack of important phytochemicals, dietary fiber, and essential micronutrients.
Broader epidemiological studies consistently link high intake of animal-based foods, particularly red and processed meats, with an increased risk of cardiovascular diseases, certain cancers, and mortality.
Study Methodology
Researchers analyzed nine eligible studies published between 2021 and 2025. These studies included case studies, surveys, a comparative modeling study, and an exploratory study.
Exclusions were made for studies with over 10% plant-based energy intake, in vitro studies, preprints, animal studies, other reviews, conference papers, book chapters, and unpublished research. It was noted that the definition of the CD varied among the analyzed studies.
Nutritional Adequacy and Cardiometabolic Findings
Nutrient Deficiencies- Two studies found multiple nutrients to be insufficient compared to dietary reference values (DRVs).
- Specifically, intakes of thiamin, magnesium, iron, calcium, potassium, iodine, folate, and vitamins C and D were reported below DRVs.
- Dietary fiber intake was also consistently lower than recommended.
- Vitamin A intake exceeded recommended levels, especially in diets high in liver-derived retinol.
- Four studies reported self-reported or clinically observed positive impacts on disease progression, sometimes leading to reduced medication use.
- Specific improvements included triglyceride-to-high-density lipoprotein cholesterol ratio, C-reactive protein, γ-glutamyl transferase, iron status, and reduced fecal calprotectin in individuals with inflammatory bowel disease.
- Triglycerides and glycated hemoglobin improved in individuals with metabolic disorders.
- Both studies that noted improvements also observed increases in total cholesterol (TC), platelet counts, and low-density lipoprotein cholesterol (LDL-C).
- Despite improvements in some metabolic parameters, LDL-C and TC were significantly elevated in individuals with metabolic disorders.
- One case report detailed health deterioration, including kidney stones, while on the CD, which resolved after cessation.
- One study indicated no significant differences in gut microbiome diversity and functionality between an omnivorous diet and the CD.
- Motivations for adopting the CD included perceived health benefits, ethical considerations, and perceptions of naturalness.
- Some individuals reported improvements in overall health, highlighting the diet's simplicity and positive sensory experiences.
- One study noted that individuals following a zero-carbohydrate/CD lifestyle often faced social conflict outside their community, including challenges with healthcare professionals and family/friend networks.
Conclusion
The review suggests that the carnivore diet may offer short-term health improvements, possibly due to placebo effects, subjective perceptions, and ketosis-related metabolic adaptations. However, the diet may elevate the risk of cardiovascular and renal complications, contribute to micronutrient deficiencies and low fiber intake, and lead to adverse lipid profile changes.
Due to limitations in current scientific evidence, such as a lack of control groups, short intervention durations, and small sample sizes, the long-term safety of the CD cannot be assessed.
Therefore, long-term adherence to the carnivore diet is not recommended.