Core premise

• People can find health benefits through carnivore and vegan diets; the clinical goal is to support success while applying an appropriate risk-benefit analysis.
• Nutrition and medicine often focus on side effects of ketogenic or carnivore therapy without the same risk-benefit comparison used for medications; metabolic therapies can have a much lower risk profile than many drugs.
• A prominent nutrition researcher was quoted about LDL increases with a keto-like low-carbohydrate, high-fat diet saying the risks outweighed the benefits, while the benefits had not been assessed in that judgment.[1]
• When these diets are used for a medical condition, an experienced healthcare professional is very important when available, and most foreseeable nutrient concerns can be tested, monitored, supplemented, or otherwise addressed.

Carnivore: clinical experience and risk-benefit case

• Initial dietetic objections to carnivore centered on inadequacy and insufficient variety, but people were happy, felt better mentally and physically, and often lost weight, making a well-formulated carnivore-ketogenic diet worthy of reevaluation.
• Carnivore and carnivore-ketogenic are not the same thing: someone can eat carnivore without being in ketosis, depending on protein intake and how the diet is formulated.
• A person preparing to start ketogenic therapy had severe tardive dyskinesia from a psychiatric medication used years earlier, remained on three or four psychiatric medications plus another drug for the tardive dyskinesia, and struggled with the side effect continuously.
• That case illustrates the risk-benefit comparison: potential nutrient deficiencies from dietary therapy need to be weighed against medication harms; people can sometimes use fewer medications or occasionally come off medications, although getting everyone off medication is not the goal.
• A vitamin C deficiency or scurvy is easier to correct with supplementation than lifelong tardive dyskinesia.

Carnivore-ketogenic diet: ketosis and setup

• Enough protein can supply glucose and reduce the need to make ketones, while elimination effects can still occur without ketosis and ketosis may add separate benefits.
• A gradual transition can be useful; a common target is about a 1.5:1 fat-to-protein-plus-carbohydrate ratio, roughly 75-77% of calories from fat, with individual variation in the ratio needed for ketosis.
• As a rough 1,700-1,800 kcal example, this can mean about five ounces of cooked protein at each of three meals with roughly two tablespoons of added fat per meal.
• Carnivore can be logistically simple because there are fewer food choices and less calculation than in many ketogenic diets.
• Scurvy is an obvious concern, yet people can remain carnivore for years without developing it; theories involve altered vitamin-C requirements, absorption, and competition, but good studies establishing why are absent.
• Chicken liver supplies more vitamin C than beef liver, and a low-dose multivitamin or targeted supplement is an easy way to cover uncertain long-term gaps when tolerated.
• Iodine can come from fish or iodized salt; pink or Himalayan salt is not an iodine source, and excessive high-dose iodine supplementation should be avoided. Sodium-potassium salt blends can also help with electrolytes.

Fiber, bowel function, and the microbiome

• Standard fiber recommendations do not necessarily fit every ketogenic or carnivore patient: one patient used a very-low-fiber keto formula for more than 20 years with good gut health, and low-residue diets can help severe gastrointestinal problems.
• A 10-patient Crohn's disease and ulcerative-colitis case series using carnivore-ketogenic therapy found clinical improvements in all 10 cases, with several patients remaining on the diet for five years or longer.[2]
• Temporary carnivore can also function as an elimination approach; one family used it while healing gastrointestinal problems and later reintroduced foods they had previously been unable to tolerate.
• Evidence used to justify fiber is generally generated in higher-carbohydrate dietary settings, so the same assumptions may not transfer unchanged to a ketogenic setting.
• A bowel movement every three days is not constipation by itself when the person is comfortable, while daily bowel movements do not guarantee that stool is not being retained; symptoms and function matter more than frequency alone.
• Magnesium can be useful when sleep, bowel function, or intake indicates a need.
• Some carnivore reviews raise placebo effects as an explanation for benefits, but benefits persisting for years are difficult to reduce to a short-lived placebo response.[3]
• A recent carnivore study found a gut microbiome that remained diverse but shifted in composition, reinforcing how immature the field is and how little certainty exists about one universally healthy microbiome.[4]
• With gut health, the practical focus is whether the person is recovering and functioning well now, because microbiome science is still a "wild west."

Cancer, phytonutrients, and metabolic context

• Red meat has an association with colorectal cancer, but much of that evidence is observational and depends on recalled diet; dietary context, processed meat, cooking methods, body weight, and metabolic health all matter.
• A well-formulated carnivore-ketogenic plan here is not necessarily a giant steak diet: about five ounces of meat per meal can fit the target, while processed meat, charring, and foods eaten alongside meat can change the context.
• U.S. prevalence figures of about 0.4% for colorectal cancer, 6-8% for serious mental illness, and more than 20% for any mental illness illustrate why the relative clinical priorities can differ.
• The relevant comparison is not risk versus zero risk: serious psychiatric illness is common, psychiatric drugs can have major metabolic costs, and a carnivore-ketogenic diet may provide meaningful benefits that must be weighed against possible long-term harms.
• Phytonutrients and antioxidants can be beneficial, but their absence is not by itself a reason to reject a therapy that is working; the balance can also change if the diet is temporary or metabolic health improves.
• Most nutrition research outside keto is performed during carbohydrate metabolism, so physiological assumptions from that literature do not automatically transfer to ketosis.
• Thyroid medication is one example where needs can change quickly during ketosis, making individualized monitoring more useful than assuming the usual recheck interval applies.
• LDL is measurable and does not automatically disqualify the diet; when it rises substantially, a coronary-artery calcium scan can provide a low-level look at whether concern and further testing or cardiology evaluation are warranted.
• The approach is to see whether LDL actually becomes an issue, monitor metabolic health, and escalate cardiovascular evaluation when the findings warrant it.
• Psychiatric medications commonly cause weight gain and metabolic deterioration, while people with serious mental illness can die 10-20 years earlier, making metabolic consequences part of the same risk-benefit calculation.

Carnivore nutrients, bone health, and clinical support

• "Nose to tail" is less important than nutrient variety: fish, poultry, beef, pork, and organs can all contribute, and a food-tracking app can reveal what is missing.
• A colleague had a beef-only carnivore patient develop an essential-fatty-acid deficiency that resolved with omega-3 supplementation; grass-finished beef contains more omega-3 than grain-finished beef but far less than fish.
• Vitamin E, vitamin K, and calcium also deserve attention; bone-in fish such as sardines can provide calcium, while calcium supplements have their own potential risks.
• Bone health is not assured after five or ten years; DEXA scanning is standard in ketogenic epilepsy care, and DEXA after long-term carnivore use is an off-the-cuff idea that might be useful simply to make sure.[5]
• Protein and physical exercise support bone health, and almost every nutrient or safety concern here has a practical way to measure, follow, check, or supplement.
• Asking every patient to obtain a doctor's permission before keto can shift responsibility onto a clinician unfamiliar with the therapy; patients should inform their clinician, and genuine contraindications should be addressed.
• For medical-condition use, guidance from a healthcare team remains important, but keto-experienced clinicians are scarce; the consensus guidelines from Georgia Ede and colleagues can help clinicians understand ketogenic metabolic therapy.[6]
• An ideal team can include a keto-skilled physician, dietitian, health coach, or therapist, but access and affordability are real limitations, so training more professionals is necessary.

Vegan-ketogenic diet

• Vegan diets are more medically accepted and better studied than carnivore, but their nutrient deficiencies are also well known and generally addressable, especially vitamin B12, iron, iodine, and vitamin D.
• Removing processed fortified foods can reduce intake of nutrients that were being supplied through enrichment and fortification.
• Ketogenic therapy can reduce folate intake when fortified carbohydrate foods are removed; whether this increases neural-tube-defect risk is uncertain, so women who could become pregnant should use supplementation as a simple precaution.[7]
• Vitamin B12 supplementation is an absolute requirement on a vegan diet because deficiency can cause severe neurologic illness.
• Ethical, religious, and cultural reasons to remain vegan should be respected; when veganism is only an experiment and is not helping, adding animal protein can be an option, as some patients in the IBD case series improved after moving from vegan to carnivore.[2]
• Vegan-keto is harder to make ketogenic because plant protein sources bring more carbohydrate, so it often allows more carbohydrate and uses MCT oil or an MCT-style diet to support ketosis.
• Plant proteins are generally less bioavailable and may not provide all amino acids in the same proportions as animal protein, so variety and repeated three-to-four-day food tracking can identify gaps.

Protein, omega-3s, and follow-up

• Protein at 0.8 g/kg, the RDA, is a basement, not an ideal target, while WHO guidance can go somewhat lower; when a vegan patient is functioning well at the low end, the diet can remain while protein rises through beans, lentils, hemp, tofu, and other sources even as carbohydrate rises.[8]
• Outcomes should include the condition being addressed as well as metabolic health, body composition, lean mass, and strength.
• Vegan omega-3 intake needs attention because conversion of ALA to EPA and DHA is low; chia and flax can help, and an omega-3 supplement is often a sensible addition.
• Iodine, calcium, and vitamin D overlap as possible gaps on both carnivore and vegan diets; at the restrictive ends of keto a modest multivitamin is often useful, and tracking at about 75% of most nutrients is generally sufficient.
• Before or very early in ketogenic therapy, baseline labs are needed; repeat them after about three to four months and, when continuing, about every six to nine months, adding diet-specific tests such as B12, MMA, and zinc and thinking about DEXA after long-term use.
• The central practical rule is to measure what can be measured, correct deficiencies that can be corrected, and work with a qualified professional especially when ketogenic therapy is used for a medical condition.

Closing point

• Carnivore and vegan diets are too often handled as polarized absolutes; people can find health benefits with both approaches, both can have manageable deficiencies, and both can be designed as ketogenic therapies when ketosis is the goal.
• A risk-benefit analysis should judge the whole intervention, including benefits, nutrient status, medication risks, metabolic health, and measurable adverse effects, without rejecting a diet because it does not fit a preferred dietary model.

References

1. [04:53] 'Keto-like' diet may be associated with a higher risk of heart disease, according to new research — https://www.cnn.com/2023/03/05/health/keto-low-carb-high-fat-diets-heart-disease
2. [19:39] Case report: Carnivore–ketogenic diet for the treatment of inflammatory bowel disease: a case series of 10 patients — https://doi.org/10.3389/fnut.2024.1467475
3. [22:05] Carnivore Diet: A Scoping Review of the Current Evidence, Potential Benefits and Risks — https://doi.org/10.3390/nu18020348
4. [23:37] Long-term adherence to the carnivore diet and its impact on the gut microbiota: a cross-sectional study — https://doi.org/10.1530/MAH-25-0015
5. [40:17] Optimal clinical management of children receiving dietary therapies for epilepsy: Updated recommendations of the International Ketogenic Diet Study Group — https://doi.org/10.1002/epi4.12225
6. [43:04] Awareness and best practices in using ketogenic therapy to treat serious mental illness: a modified Delphi consensus — https://doi.org/10.3389/fnut.2026.1749406
7. [47:22] Low carbohydrate diets may increase risk of neural tube defects — https://doi.org/10.1002/bdr2.1198
8. [51:43] Protein and amino acid requirements in human nutrition: report of a joint FAO/WHO/UNU expert consultation — https://iris.who.int/bitstream/handle/10665/43411/WHO_TRS_935_eng.pdf