The Carnivore Diet: When Elimination Goes All the Way

What It Is

The carnivore diet is the most extreme elimination diet in existence. All animal foods, zero plant foods. Meat, fish, eggs, and optionally dairy — butter, ghee, aged cheese. Nothing from the plant kingdom. No vegetables, no fruits, no grains, no legumes, no nuts, no seeds, no herbs, no spices (salt is a mineral, not a plant — salt stays).

This is not a long-term dietary recommendation for everyone. It is a diagnostic and therapeutic tool — the cleanest possible baseline from which to identify what a human body can and cannot tolerate.

Why It Works for Some People

Every plant produces chemical defense compounds. Unlike animals, plants cannot run from predators. They wage chemical warfare instead. Oxalates, lectins, phytates, saponins, salicylates, tannins, goitrogens, solanine (nightshades), trypsin inhibitors, FODMAPs, histamine (in fermented plant foods), phytoestrogens — the list is long.

For most people, these compounds are handled without issue. The gut degrades them, the liver detoxifies them, and they pass through unremarkably. But for patients with compromised gut barriers, impaired detoxification, mast cell activation, or autoimmune dysregulation, any or all of these compounds can trigger inflammation, immune activation, and symptoms.

The carnivore diet eliminates every single plant-based antinutrient simultaneously. For the patient who “reacts to everything” — who has tried the Autoimmune Protocol and still reacts, who has eliminated FODMAPs and lectins and nightshades and oxalates individually with partial but incomplete relief — carnivore removes the entire category at once. It answers the question: what happens when we remove all plant matter?

Who Benefits

Severe autoimmune disease that has failed AIP: When even AIP-compliant foods trigger flares, carnivore provides the next level of elimination. Rheumatoid arthritis, ankylosing spondylitis, psoriasis, lupus, Hashimoto’s thyroiditis.

Inflammatory bowel disease: Crohn’s disease and ulcerative colitis patients who cannot tolerate fiber, plant roughage, or FODMAP residue in any amount. The complete absence of plant fiber allows the inflamed intestinal mucosa to rest.

Severe IBS and multiple food sensitivities: Patients with MCAS (Mast Cell Activation Syndrome) who react to seemingly random foods often stabilize on carnivore because every potential plant trigger has been removed.

Treatment-resistant mental health conditions: Jordan Peterson and his daughter Mikhaila Peterson brought public attention to this. Mikhaila, diagnosed with juvenile rheumatoid arthritis, severe depression, and chronic fatigue, found resolution of all symptoms on an all-beef diet after failing every other intervention. Georgia Ede MD, a Harvard-trained psychiatrist, now advocates carnivore approaches for metabolic psychiatry — framing depression, anxiety, bipolar disorder, and even psychosis as metabolic disorders of the brain where plant antinutrients and inflammatory triggers perpetuate neuroinflammation.

Severe dermatological conditions: Eczema and psoriasis that persist despite AIP and topical treatments sometimes resolve on carnivore.

Chronic pain and fibromyalgia: When systemic inflammation from food triggers maintains central sensitization, removing all triggers can break the cycle.

Lyme disease and chronic infections: Reducing immune activation load by eliminating all dietary immune triggers allows the immune system to focus resources on the infection.

The Lion Diet: The Strictest Form

Mikhaila Peterson’s Lion Diet reduces carnivore to its absolute minimum: ruminant meat (beef, lamb, bison), salt, and water. Nothing else — no pork, no poultry, no fish, no eggs, no dairy, no coffee, no supplements. This serves as the ultimate baseline. Once symptoms stabilize (typically 30-90 days), individual foods are reintroduced one at a time with meticulous symptom tracking. Each reaction narrows the diagnostic picture. Each tolerated food expands the long-term diet.

Paleomedicina: Clinical Protocol from Hungary

The Paleomedicina clinic in Budapest, led by Dr. Csaba Toth and Dr. Zsofia Clemens, uses what they call the Paleolithic Ketogenic Diet (PKD) — a specific carnivore-ketogenic protocol. The parameters: fatty meat, organ meats, and animal fat in a 2:1 fat-to-protein ratio by weight. Organ meats are mandatory, not optional — they consider them essential for micronutrient completeness.

Their published case reports document clinical improvements in: autoimmune conditions (Crohn’s, Type 1 diabetes with partial beta-cell recovery, rheumatoid arthritis), epilepsy, cancer (as adjunctive metabolic therapy), and intestinal permeability normalization measured by PEG 400 test. Their emphasis on organ meats and animal fat — not lean meat — distinguishes their protocol from casual carnivore eating.

Nutrient Concerns: Addressing the Objections

”Where Do You Get Fiber?”

Dietary fiber is not an essential nutrient. There is no clinical requirement for fiber intake. Erickson’s 2012 systematic review found no benefit of fiber supplementation for constipation in many patient populations. Many people’s gastrointestinal symptoms improve without fiber — particularly those with IBS, SIBO, and IBD where fiber feeds pathogenic organisms or mechanically irritates inflamed tissue. Bowel transit often normalizes on carnivore after an initial adjustment period of 2-4 weeks.

”Where Do You Get Vitamin C?”

Vitamin C requirements are dramatically lower in the absence of carbohydrate intake. Glucose and ascorbic acid compete for the same GLUT1 transporters — without dietary glucose flooding these receptors, vitamin C is recycled more efficiently and less is needed. Frank scurvy has not been reported in well-fed carnivore populations historically (the Inuit, the Masai, the Plains tribes who ate primarily buffalo for centuries) or in modern self-reporting carnivore communities. Fresh meat — particularly organ meats — contains meaningful amounts of vitamin C (liver contains 25-35mg per 100g).

”Where Do You Get Your Vitamins?”

Organ meats are the answer. Liver provides vitamin A (retinol — the preformed version, not beta-carotene that requires conversion), B12 (up to 3,000% of daily value per 100g), folate, heme iron, copper, riboflavin, and CoQ10. Heart is the richest dietary source of CoQ10 and provides B vitamins for mitochondrial energy production. Kidney supplies B12, selenium, and riboflavin. Eating organ meats 1-2 times per week covers the vast majority of micronutrient requirements.

Electrolytes

The carnivore adaptation phase, like keto adaptation, involves significant electrolyte shifts as insulin drops and the kidneys excrete sodium. Supplement sodium liberally — salt everything generously, drink salted water or bone broth. Supplement potassium and magnesium through the transition. This resolves the headaches, fatigue, and muscle cramps that otherwise discourage people in the first two weeks.

Calcium

Bone broth (cooked long enough to extract minerals from bones), small fish eaten with bones (sardines, anchovies), and dairy (if tolerated) provide calcium. Eggshell calcium is another option.

Protocol for Functional Medicine Use

Phase 1: Strict Carnivore (30-90 Days)

Ruminant meat (beef, lamb, bison) forms the base — these are the least reactive animal proteins. Salt and water. Add eggs if tolerated (introduce after 1-2 weeks and assess). Add butter or ghee if tolerated. Eat to satiety — no calorie counting, no portion restriction. The body’s hunger and satiety signals normalize remarkably on carnivore because there are no hyperpalatable processed foods overriding them.

Track symptoms daily. Most adaptation effects — fatigue, headaches, bowel changes (diarrhea is common initially as bile acid production upregulates, constipation in some as the microbiome shifts) — resolve by weeks 2-4.

Phase 2: Expand Animal Foods

After stabilization, broaden the animal food repertoire. Add pork, poultry, fish, shellfish. Introduce organ meats — liver 1-2 times per week minimum (start with 2 ounces and increase, as liver is extremely nutrient-dense and can cause nausea if introduced too aggressively). Add bone broth as a daily staple.

Phase 3: Strategic Reintroduction

This is where carnivore transitions from elimination to diagnostic tool. Reintroduce one food every 5-7 days, allowing enough time for delayed reactions to manifest.

Reintroduce first (least reactive): Well-cooked low-oxalate vegetables — zucchini, cucumber, peeled and deseeded. Avocado. Cooked berries (blueberries). Olive oil. Coconut oil.

Reintroduce second: Sweet potato. White rice (least reactive grain). Other cooked fruits. Squash varieties.

Reintroduce last (most reactive): Nightshades (tomatoes, peppers, potatoes, eggplant). Nuts and seeds. Legumes. Grains. Dairy beyond butter.

Exit Strategy

Most people do not stay strict carnivore permanently. The protocol builds a personalized diet: an animal-based core supplemented with individually tolerated plant foods. Dr. Paul Saladino MD has articulated the “animal-based” framework — meat, organs, fruit, honey, and raw dairy, excluding the most problematic plant categories (seeds, grains, legumes, nightshades) while including the least problematic (fruits, certain cooked vegetables).

Monitoring

Lipid panel: LDL cholesterol often rises significantly on carnivore, sometimes dramatically. This requires nuanced assessment, not reflexive alarm. Check LDL particle number (LDL-P via NMR LipoProfile), ApoB concentration, triglyceride-to-HDL ratio (target below 2.0), Lp(a), and inflammatory markers (CRP, homocysteine, fibrinogen). A pattern of low triglycerides, high HDL, low CRP, and large buoyant LDL particles is metabolically favorable despite high LDL-C. However, elevated ApoB or high LDL-P with elevated Lp(a) warrants careful ongoing monitoring.

Comprehensive metabolic panel: BUN (blood urea nitrogen) rises on high protein intake — this is expected and does not indicate kidney damage in the absence of elevated creatinine. Monitor kidney function with GFR and creatinine.

Inflammatory markers: CRP should improve. If it does not, something else is driving inflammation.

Micronutrients: Vitamin D, B12, folate, and vitamin C (if there is clinical concern). With organ meat consumption, deficiencies are rare.

Thyroid function: T3 can decrease without carbohydrate intake, as insulin facilitates T4-to-T3 conversion. Monitor free T3 specifically. Some patients benefit from cyclical carbohydrate meals to support thyroid function.

Gut health: Consider periodic GI-MAP testing. The microbiome shifts significantly on carnivore — bacterial diversity measured by 16S rRNA may decrease, but this does not automatically indicate harm. Monitor for opportunistic overgrowth and inflammatory markers rather than diversity alone.

Cautions and Contraindications

Eating disorder history: Any severely restrictive dietary protocol can trigger or exacerbate disordered eating patterns. Assess psychological readiness carefully. If orthorexia or restrictive tendencies are present, carnivore is not appropriate regardless of physical benefits.

Kidney disease: High protein intake increases the kidney’s filtration workload. Patients with existing chronic kidney disease (GFR below 60) should not adopt high-protein diets without nephrologist oversight.

Gout: Purines from meat metabolism produce uric acid. Paradoxically, many carnivore dieters report improvement in gout — likely because reduced insulin improves renal uric acid excretion and the elimination of fructose (a potent uric acid driver) offsets the purine load. However, initial flares can occur during adaptation. Monitor uric acid levels.

Pregnancy: Insufficient data exists for strict carnivore during pregnancy. Ensure adequate folate (liver provides this), choline (eggs and liver), and consider a less restrictive animal-based approach rather than strict carnivore.

Always under practitioner supervision for therapeutic use. Carnivore is a clinical tool, not a casual lifestyle choice. Used correctly — as a diagnostic elimination protocol with systematic reintroduction — it reveals what the body can and cannot tolerate with a clarity that no other dietary approach matches.