On the carnivore diet (also called a zero carb diet), only animal products are consumed. The lion diet is a highly restrictive form of the carnivore diet wherein only beef, salt, and water are consumed. 

     Due to being extremely low in carbohydrates, the carnivore diet was once used to nourish people with type 1 diabetes 1-3. It has since been associated with numerous self-reported health benefits, including improvements in symptoms of auto-immune disorders.

      The carnivore diet is often compared to the Inuit diet, which tends to include a higher proportion of organ meats – important for preventing some nutritional deficiencies5, though clean sources should be sought to avoid heavy metal over-exposure 6,7 – seafood, and raw meat8,9, the latter of which the Inuit have apparently adapted to eat safely10. People outside of the indigenous cultural and gene pools have claimed to thrive eating raw animal foods11, but it should be noted that it is important to seek sanitary sources and to consider the increased risk of food poisoning, especially if using immune-inhibiting therapy 12,13.

      To prevent the risk of fatty acid deficiencies, also known as rabbit starvation or protein poisoning in the context of a carnivore-type intake pattern, care should be taken not to consume exclusively lean foods.

     Because of the consistent and potentially high intake of saturated fats common in a carnivore diet, some individuals may experience increased risk factors for chronic diseases, particularly cardiovascular and metabolic14,15. If signs suggest this to be the case, the danger may be mitigated by consuming mostly (but of course, not exclusively) lean foods plus fatty fish16.

     In individuals at risk for colon cancer and gout, e.g., due to genetic predisposition, a carnivore diet high in red meat in particular may be disadvantageous15,17,18. Fortunately, there are other culinary options in the diet.

     No less important to take into account, the carnivore diet has raised concerns about insufficient quantities of certain vitamins, minerals, and dietary fiber. Fortunately, most essential nutrients are found in abundance in animal foods. For individuals with increased needs, it may be beneficial to supplement certain nutrients to reduce the risk of deficiencies4,19.

      Because of the above issues, as well as the potentially high cost and temptation to deviate when one is in “mixed” company, the carnivore – and especially the lion – diet is considered difficult to sustain long-term. For this reason, it may be most successful if limited to use during flares, rather than as a maintenance/preventive regimen.

Foods to Favor

• Beef (exclusively in the lion diet)

• Game (e.g., venison, rabbit)

• Goat

• Lamb

• Organ meats (from all game or livestock animals)

• Pork

• Poultry (e.g., chicken, duck, goose)

• Seafood (e.g., fish, shellfish)

• Dairy (including from animals other than cows)

• Eggs (including from animals other than chickens)

Foods to Forgo

• Fruits

• Legumes

• Nuts

• Seeds

• Vegetables

Reported side effects of the carnivore diet include diarrhea, nausea, vomiting, constipation, headache, hydration issues from fluid loss, dizziness, fatigue, and insomnia. Some of these may be inherently temporary, while others may be addressed through adjustments as noted above.

For some individuals, the carnivore diet may not be suitable, e.g., with certain types of kidney or liver disease. In these cases, a Paleo diet – either animal- or plant-based – may provide a viable compromise.

References

1. Brunton TL. Lectures on the Pathology and Treatment of Diabetes Mellitus. Br Med J. Jan 10 1874;1(680):39-41. doi:10.1136/bmj.1.680.39

2. Lennerz BS, Koutnik AP, Azova S, Wolfsdorf JI, Ludwig DS. Carbohydrate restriction for diabetes: rediscovering centuries-old wisdom. J Clin Invest. Jan 4 2021;131(1)doi:10.1172/JCI142246

3. Rollo J. Account of Two Cases of Diabetes Mellitus, with Remarks. Ann Med (Edinb). 1797;2:85-105. 

4. Lennerz BS, Mey JT, Henn OH, Ludwig DS. Behavioral Characteristics and Self-Reported Health Status among 2029 Adults Consuming a “Carnivore Diet”. Curr Dev Nutr. Dec 2021;5(12):nzab133. doi:10.1093/cdn/nzab133

5. Bjerregaard P, Mulvad G. The best of two worlds: how the Greenland Board of Nutrition has handled conflicting evidence about diet and health. Int J Circumpolar Health. Jul 10 2012;71:18588. doi:10.3402/ijch.v71i0.18588

6. Bjerregaard P, Hansen JC. Organochlorines and heavy metals in pregnant women from the Disko Bay area in Greenland. Sci Total Environ. Jan 17 2000;245(1-3):195-202. doi:10.1016/s0048-9697(99)00444-1

7. Gagne D, Lauziere J, Blanchet R, et al. Consumption of tomato products is associated with lower blood mercury levels in Inuit preschool children. Food Chem Toxicol. Jan 2013;51:404-10. doi:10.1016/j.fct.2012.10.031

8. Elvevoll EO, Osterud B. Impact of processing on nutritional quality of marine food items. Forum Nutr. 2003;56:337-40. 

9. Frost P. The Problem of Vitamin D Scarcity: Cultural and Genetic Solutions by Indigenous Arctic and Tropical Peoples. Nutrients. Sep 30 2022;14(19)doi:10.3390/nu14194071

10. Hauptmann AL, Paulova P, Hansen LH, Sicheritz-Ponten T, Mulvad G, Nielsen DS. Microbiota in foods from Inuit traditional hunting. PLoS One. 2020;15(1):e0227819. doi:10.1371/journal.pone.0227819

11. Brown S. What is the Viral Raw Meat Trend About? Very Well Health. New York: Dotdash Media, Inc.; 2023.

12. Bouchard E, Bonin M, Sharma R, et al. Use of stable isotopes to reveal trophic relationships and transmission of a food-borne pathogen. Sci Rep. Feb 2 2024;14(1):2812. doi:10.1038/s41598-024-53369-6

13. Safer Food Choices for People With Weakened Immune Systems. Atlanta: Centers for Disease Control (CDC); 2024.

14. Houttu V, Grefhorst A, Cohn DM, et al. Severe Dyslipidemia Mimicking Familial Hypercholesterolemia Induced by High-Fat, Low-Carbohydrate Diets: A Critical Review. Nutrients. Feb 15 2023;15(4)doi:10.3390/nu15040962

15. Najjar RS. The Impacts of Animal-Based Diets in Cardiovascular Disease Development: A Cellular and Physiological Overview. J Cardiovasc Dev Dis. Jun 30 2023;10(7)doi:10.3390/jcdd10070282

16. Mangravite LM, Chiu S, Wojnoonski K, Rawlings RS, Bergeron N, Krauss RM. Changes in atherogenic dyslipidemia induced by carbohydrate restriction in men are dependent on dietary protein source. J Nutr. Dec 2011;141(12):2180-5. doi:10.3945/jn.111.139477

17. Farvid MS, Sidahmed E, Spence ND, Mante Angua K, Rosner BA, Barnett JB. Consumption of red meat and processed meat and cancer incidence: a systematic review and meta-analysis of prospective studies. Eur J Epidemiol. Sep 2021;36(9):937-951. doi:10.1007/s10654-021-00741-9

18. Li R, Yu K, Li C. Dietary factors and risk of gout and hyperuricemia: a meta-analysis and systematic review. Asia Pac J Clin Nutr. 2018;27(6):1344-1356. doi:10.6133/apjcn.201811_27(6).0022

19. O’Hearn A. Can a carnivore diet provide all essential nutrients? Curr Opin Endocrinol Diabetes Obes. Oct 2020;27(5):312-316. doi:10.1097/MED.0000000000000576