Overview of the Carnivore and Vegan Diets
The carnivore diet consists exclusively of animal products like meat, fish, eggs, and sometimes dairy, eliminating all plant foods. It is a zero-carb, high-protein, high-fat approach often promoted for short-term weight loss and reducing inflammation. The vegan diet excludes all animal products, focusing on fruits, vegetables, grains, legumes, nuts, and seeds. It emphasizes fiber-rich, nutrient-dense plants and is linked to environmental and ethical benefits.
Both diets can lead to short-term improvements like weight loss by cutting processed foods and sugars, but their long-term health impacts differ significantly. Well-planned vegan diets are supported by extensive research for reducing chronic disease risk, while the carnivore diet lacks robust evidence and carries substantial risks due to nutrient gaps and high saturated fat intake. Neither is inherently "healthy" without planning, but vegan diets align more closely with established guidelines from organizations like the American Heart Association and WHO.
Health Benefits and Risks Comparison
Below is a table summarizing key aspects based on scientific studies, including cohort analyses (e.g., EPIC-Oxford, Adventist Health Study-2), randomized trials (e.g., Stanford Twins Study), and meta-analyses. Evidence for carnivore is mostly self-reported surveys; vegan data comes from larger, long-term prospective studies.
Aspect |
Carnivore Diet |
Vegan Diet |
---|---|---|
Weight Loss |
Short-term: Effective due to low carbs and high satiety (e.g., 2021 survey of 2,029 adherents reported BMI reductions of ~10-20 lbs in 9-20 months). Long-term: Unsustainable; weight regain likely due to restrictiveness. |
Short-term: Comparable or better (e.g., Stanford Twins: 4.2 lbs more loss in 8 weeks vs. omnivore). Long-term: Sustains lower BMI (e.g., EPIC-Oxford: vegans 2-3 kg lighter; 23% lower obesity risk). |
Heart Health |
Short-term: May lower triglycerides and improve insulin sensitivity in some. Long-term: High saturated fat raises LDL cholesterol (e.g., 2021 survey: 30-50% had elevated LDL); increased CVD risk from red/processed meat (WHO: processed meat carcinogenic). |
Short-term: Lowers LDL (e.g., Twins: 10% drop) and blood pressure. Long-term: 15-25% lower ischemic heart disease risk (EPIC-Oxford, AHS-2); lower stroke risk if B12 supplemented, but higher hemorrhagic stroke in some studies. |
Diabetes Risk |
Short-term: Improves blood sugar (e.g., 2021 survey: 84% reduced meds). Long-term: Unknown; high protein may strain kidneys in diabetics. |
Short-term: Better glycemic control (e.g., 2006 study: 43% reduced meds vs. 26% on standard diet). Long-term: 23-62% lower T2DM risk (AHS-2); improves insulin sensitivity. |
Cancer Risk |
Short-term: Anecdotal inflammation reduction. Long-term: High red/processed meat intake raises colorectal cancer risk (IARC: processed meat Group 1 carcinogen; 18% increased risk per 50g/day). |
Short-term: Anti-inflammatory effects from fiber/antioxidants. Long-term: 15% lower overall risk (2017 meta-analysis); protective against colorectal, prostate (35% lower in men). |
Bone Health |
Short-term: High protein may support muscle. Long-term: No fiber/vitamin C; potential for low BMD from nutrient gaps (limited data; risks like osteoporosis unstudied). |
Short-term: High calcium from plants if fortified. Long-term: 43% higher fracture risk if low calcium/B12 (EPIC-Oxford); mitigated by supplements (e.g., UK Biobank: vegans 2.3x hip fracture risk vs. meat-eaters). |
Gut Health |
Short-term: May reduce bloating (no fiber). Long-term: Zero fiber alters microbiome; increases inflammation, constipation, and colon cancer risk (e.g., high-protein byproducts harm gut lining). |
Short-term: High fiber promotes diversity. Long-term: Supports microbiome (e.g., more protective bacteria); lowers diverticular disease risk (EPIC-Oxford: 31% lower). |
Nutrient Concerns |
Deficiencies: Vitamin C, folate, fiber, antioxidants (no plants); risks scurvy, gut issues. High sodium/cholesterol from meats. Multivitamins may partially address vitamin deficiencies (e.g., C, E), but cannot replace fiber, antioxidants, or plant phytonutrients; overall, supplementation is insufficient for long-term risks. |
Deficiencies: B12 (100% risk without supplements), iron, calcium, omega-3s, iodine; risks anemia, fatigue, bone loss. Easily mitigated with planning/fortification. Multivitamins or targeted supplements (e.g., B12 at 250 mcg/day, vitamin D, iron, omega-3 algae oil) are highly recommended and effective for preventing deficiencies. |
Mental Health |
Short-term: Anecdotal mood boost from ketosis. Long-term: Unknown; potential from nutrient gaps (e.g., low omega-3s). |
Short-term: Stable energy from fiber. Long-term: Lower depression risk (e.g., 2018 review: anti-inflammatory effects); but B12 deficiency linked to mood issues. |
Sustainability |
Low: Restrictive; 70-90% abandon due to boredom/deficiencies (anecdotal). |
Moderate-High: Flexible; long-term adherents show benefits if supplemented (e.g., EPIC-Oxford: 20+ years data). |
Both diets carry distinct risks that should be carefully considered. The carnivore diet increases the likelihood of elevated cholesterol, heart disease, colorectal cancer, gut dysbiosis, and deficiencies in essential vitamins like C and folate, potentially leading to conditions such as scurvy or chronic inflammation. In contrast, the vegan diet may heighten risks of B12 deficiency (causing neurological issues), anemia from low iron, weakened bones due to insufficient calcium or vitamin D, and fatigue if omega-3s are lacking, though these are generally preventable with proper supplementation and planning.
Detailed Analysis
Carnivore Diet: Limited Evidence, High Risks
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Short-Term Effects: A 2021 survey of 2,029 adherents (median 14 months) reported high satisfaction, weight loss, and diabetes improvements (e.g., 92% of T2DM participants off insulin). However, this is self-reported and biased toward motivated participants; no randomized trials exist.
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Long-Term Effects: No long-term studies (>2 years). Concerns include elevated LDL (30-50% in survey), gut dysbiosis from no fiber (linked to colon cancer), and kidney strain from high protein (risk for CKD patients). Red/processed meat increases colorectal cancer by 18% per 50g/day (IARC). Overall, it's unsustainable and potentially harmful, per experts like Harvard's Christopher Gardner.
Vegan Diet: Strong Evidence, Manageable Risks
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Short-Term Effects: Randomized trials (e.g., Stanford Twins, 2023: 22 twin pairs, 8 weeks) show superior LDL reduction (10%), weight loss (4.2 lbs more), and insulin sensitivity vs. omnivore diets. A 2006 trial found 43% reduced diabetes meds vs. 26% on standard diets.
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Long-Term Effects: Prospective cohorts like EPIC-Oxford (65,000+ participants, 20+ years) and AHS-2 show 15-25% lower ischemic heart disease, 23% lower T2DM, and 15% lower cancer risk. No difference in all-cause mortality, but lower obesity and better gut health from fiber. Risks like fractures (43% higher if unsupplemented) and B12 deficiency (neurological issues) are well-documented but preventable with fortification/supplements (e.g., 50% of vegans deficient without). Meta-analyses confirm benefits for cardiometabolic health when planned.
Key Considerations
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Who Might Benefit? Vegan: Those with heart disease/diabetes risk; ethical/environmental motivations. Carnivore: Short-term for autoimmune/inflammation (anecdotal); not recommended long-term.
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Planning is Essential: For vegan, supplement B12 (250 mcg/day), ensure iron (18 mg/day women), calcium (1,000 mg/day). For carnivore, no viable mitigation for fiber/antioxidant gaps.
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Overall Verdict: A well-planned vegan diet is healthier long-term, reducing chronic disease risk by 15-25% with proper supplementation. The carnivore diet offers no proven long-term benefits and increases risks like CVD and cancer; it's a fad unsupported by science. Consult a doctor/dietitian before starting either, especially with conditions like kidney disease or pregnancy. For balanced health, consider Mediterranean-style plant-forward diets.
Resources
- Plant-based diets and long-term health: findings from the EPIC-Oxford study
- Vegetarian Dietary Patterns and Mortality in Adventist Health Study 2
- Cardiometabolic Effects of Omnivorous vs Vegan Diets in Identical Twins (Stanford Twins Study)
- Behavioral Characteristics and Self-Reported Health Status among 2029 Carnivore Diet Consumers
- Carcinogenicity of the consumption of red meat and processed meat (IARC/WHO)
- The Relationship Between Plant-Based Diet and Risk of Digestive System Cancers: A Meta-Analysis