Health Effects of the Carnivore Diet

Evidence disclaimer: There are no long-term clinical trials evaluating the health effects of a carnivore diet (a diet consisting exclusively of animal-source foods, eliminating all plant foods, and being very low in carbohydrates). All medical claims about this diet—positive or negative—are based on indirect evidence from other dietary contexts, including:

• Low-carbohydrate and ketogenic diet trials (not carnivore; include plant foods and refined vegetable oils)
• Observational red and processed meat studies in mixed Western diets (not ketogenic; confounded by refined carbohydrates and vegetable oils)
• Anecdotal reports (not clinical evidence)

Because no carnivore-specific randomized trials or prospective long-term studies exist, the long-term safety and efficacy of the carnivore diet are unknown.

Metabolic Context Matters

Most studies used to evaluate carnivore come from metabolic environments different from those induced by carnivore eating. Metabolism functions differently depending on fuel source:

These represent general tendencies; individual responses vary.

Since carnivore induces nutritional ketosis, findings from carb-based diets cannot be directly transferred. Even ketogenic diet trials do not fully apply to carnivore because they include plant foods, fiber, and plant oils. Metabolic context limits evidence transfer.

Overview of the Carnivore Diet

The carnivore diet consists of meat, fish, eggs, and sometimes dairy. Compared to standard ketogenic diets, a carnivore diet:

• Is very low in carbohydrates
• Is higher in animal protein and saturated fat
• Excludes plant-derived fats (olive oil, nuts, seeds)
• Creates a fiber-free dietary pattern

Supporters claim reduced inflammation, improved metabolic health, higher energy, and autoimmune relief. Critics warn of LDL elevation, nutrient deficiencies, cancer risk, and long-term organ stress. None of these claims are supported by carnivore-specific clinical trials.

Metabolic Effects (Glucose, Insulin, Weight)

Indirect evidence suggests carbohydrate restriction can improve metabolic markers:

(Goldenberg et al., 2021, BMJ – systematic review/meta-analysis of 23 RCTs; low-carb diets improved HbA1c and reduced diabetes medication use at 6 months; mixed-diet context; not carnivore-specific)

(Wang et al., 2024, American Journal of Medicine – meta-analysis of ketogenic RCTs; triglycerides decreased, HDL increased; biomarker-only findings; not carnivore-specific)

Interpretation: Short-term metabolic improvements are plausible under carbohydrate restriction. However:

• No studies isolate exclusive animal-based diets
• Long-term safety is unknown
• Biomarkers ≠ clinical outcomes

LDL Cholesterol and Cardiovascular Markers

LDL cholesterol often increases in a subset of individuals using ketogenic diets:

(Soto-Mota et al., 2024, American Journal of Clinical Nutrition – systematic review/meta-analysis; LDL increases most common in normal-BMI individuals; heterogeneity; not carnivore-specific)

(Patikorn et al., 2023, BMC Medicine – umbrella review; triglycerides decrease, HDL increases, pooled LDL increases; no cardiovascular outcome trials; not carnivore-specific)

LDL is a causal factor in atherosclerotic cardiovascular disease (ASCVD) in general populations:

(Ference et al., 2017, The Lancet – genetic evidence confirming LDL causality in ASCVD)
(Silverman et al., 2016, Circulation – CTT Collaboration; lowering LDL reduces cardiovascular events)

However, no randomized trials of ketogenic or carnivore diets have reported major adverse cardiovascular events or mortality, so it is unknown whether LDL changes in a fat-based metabolic state carry the same risk.

Heart Disease Claims

Epidemiologic studies often cited against carnivore do not study ketogenic or meat-only diets:

(Zeraatkar et al., 2022, Nature Medicine – Burden of Proof meta-analysis; unprocessed red meat shows weak, low-certainty association with CVD; confounded mixed-diet context; not carnivore-specific)

Heart disease risk on carnivore remains unstudied.

Cancer Claims

Cancer claims rely on observational association—not causation:

(Farvid et al., 2021, European Journal of Epidemiology – systematic review/meta-analysis; processed meat associated with colorectal cancer; weaker signals for unprocessed meat; observational; not carnivore-specific)

These findings cannot be transferred to a zero-carbohydrate, all-meat diet without direct evidence.

Gout and Uric Acid

Gout concerns rely on general population purine studies:

(Li et al., 2018, Asia Pacific Journal of Clinical Nutrition – meta-analysis; purine-rich foods associated with uric acid/gout; mixed-diet context; not ketogenic/carnivore-specific)

Gout incidence on carnivore is unknown.

Kidney Function

There are no systematic reviews or clinical trials examining renal function on exclusive animal-source diets. Safety and harm claims are unproven.

Nutrient Adequacy

Deficiency claims rely on general nutrition guidelines, not carnivore data:

(World Health Organization – Healthy Diet guidance; mixed-diet assumptions; not carnivore-specific)
(European Food Safety Authority, 2017 – Dietary Reference Values; population nutrient estimates; not meat-only physiology)

No study has measured micronutrient blood status on a carnivore diet.

Gut Microbiome

Microbiome arguments are speculative because zero-fiber diets have not been studied clinically:

(Makki et al., 2018, Cell Host & Microbe – fiber–microbiome relationships reviewed; findings cannot be extrapolated to fiber-free diets without testing; not carnivore-specific)

Microbiome effects on carnivore are unknown.

Autoimmune and Neurological Claims

Reports of symptom improvement for autoimmune and psychiatric conditions are anecdotal only. No controlled trials assess carnivore for these conditions.

Safety in Specific Populations

There is no safety research for:

• Children and adolescents
• Pregnant or breastfeeding women
• People with kidney or liver disease
• Long-term elderly use

Final Assessment

Conclusion: Current evidence is insufficient to declare the carnivore diet safe or harmful long-term. Most claims rely on indirect evidence from non-carnivore metabolic contexts. Carnivore-specific randomized trials are required to reach evidence-based conclusions.