Carnivore Diet

What it is

A carnivore diet is an eating pattern built entirely on animal foods: meat, fish, seafood, eggs, animal fats and often dairy, with all plant foods left out [1]. The strictest version, sometimes called the lion diet, is only red meat, salt and water [1]. Studies define the diet differently, and some people avoid dairy while others include it [2].

How it might work

Because the diet is very low in carbohydrate, it can put the body into ketosis, which may reduce appetite and change metabolism [1]. Reviewers also propose that ketone bodies have anti-inflammatory effects and that removing plant foods may help some gut and skin conditions; these mechanisms are proposed but not established for this diet [1].

What the research says

Weight: in an online survey of 2,029 adults who had followed the diet for a median of 14 months, participants reported their median BMI fell from 27.2 to 24.3, and 95% reported improved overall health [2]. The 2026 scoping review of the nine human studies reports weight reduction among the reported benefits, with very limited evidence quality [1].

Blood sugar: survey participants with diabetes reported a median HbA1c fall of 0.4 percentage points and reduced medication use [2]. In a 24-person study with blood tests before and after the diet, participants with pre-diabetic HbA1c or high triglycerides improved, while metabolically healthy participants saw their HbA1c and triglycerides rise [3][1]. A single case report describes remission of 20-year type 2 diabetes [4].

Cholesterol: median LDL rose from 157 to 256 mg/dL and total cholesterol from 224 to 305 mg/dL in the 24-person study [3], and survey participants with lipid results had a median LDL of 172 mg/dL [2]. A lipid-clinic review describes severe hypercholesterolemia in some patients on high-fat, low-carbohydrate diets at levels that can mimic familial hypercholesterolemia [5]. High LDL causes heart disease over time [6], but no study has measured heart attacks or deaths on this diet [1].

Nutrients: modelled meal plans met several nutrient targets but fell below recommended intakes for thiamin, magnesium, calcium, vitamin C, iron, folate and iodine depending on the version, with fibre under 1% of recommended amounts [7]. No deficiency disease has been reported in the reviewed studies [1].

Inflammatory conditions: a case series of 10 patients with inflammatory bowel disease on ketogenic, mostly carnivore, diets reported symptom-score improvements of 72 to 165 points [8], and a case report describes symptom resolution in vulvovaginal candidiasis and hidradenitis suppurativa [9].

Gut microbiome: a small feeding study found an animal-based diet shifted gut bacteria within days [10], while one small comparison of carnivore dieters and omnivores found similar microbiome diversity [1].

Doses used in studies

These are the diets and durations used in the studies, not recommendations. Survey participants had followed the diet for a median of 14 months, and 85% ate red meat daily or more often [2]. The 24-person study included people who had followed the diet for at least one month, with reported intakes up to 1,500 g of meat per day [3][1]. The inflammatory bowel disease case series used mostly meat, eggs and animal fats [8]. The nutrient modelling used four meal plans, male and female, each with a dairy version and a liver version [7].

Safety and interactions

LDL cholesterol rose in the studies that measured it, by about 100 mg/dL in the 24-person study, and high LDL causes heart disease over time [3][6]. Modelled meal plans fell short on thiamin, magnesium, calcium, vitamin C, iron, folate and iodine in some versions and provided almost no fibre [7]. Case reports describe worsening urinary stone risk factors and more gout flares in a patient with a history of kidney stones [1], and acute pancreatitis from severe high triglycerides in a 61-year-old man [11]. Raw meat and dairy carry foodborne infection risks [1]. Reported side effects in the survey were uncommon: gastrointestinal symptoms in 3.1% to 5.5%, muscle symptoms up to 4.0%, and skin symptoms up to 1.9% [2]. We found no studies of interactions between this diet and medicines; survey participants with diabetes reported reducing medication as blood sugar fell [2]. In adults without kidney disease, short trials of high-protein diets raised eGFR without signs of kidney injury, and long-term effects are unknown [12]; evidence on protein restriction in chronic kidney disease is uncertain [13]. We found no studies in pregnancy, breastfeeding or children. Some researchers propose that very low carbohydrate intake may lower requirements for certain nutrients, but this is not established [14].

Caveats and open questions

There are no randomised trials and no clinical outcomes: none of the nine human studies measured heart attacks, deaths or disease diagnoses [1]. Participants are self-selected and often motivated by health problems, and reviewers caution that placebo effects and ketosis-related metabolic changes may explain some reported improvements [1]. LDL responses vary widely between individuals, including a lean mass hyper-responder pattern [1]. Claims often point to the Maasai and Inuit, but a review notes their genetic adaptations, high activity, calorie restriction and shorter life expectancy mean those outcomes cannot be generalised to modern dieters [15]. Ordinary diets high in red and processed meat are linked to higher type 2 diabetes risk across 31 cohorts [16]; whether that applies to a strict carnivore pattern is unknown. Social media posts about the diet are overwhelmingly positive in the content analysed [17], and zero-carb dieters report strong community ties and stigma from healthcare providers [18]. Ongoing studies are testing ketogenic and carnivore (lion) diets for inflammatory bowel disease and rheumatic diseases (NCT07524244), and carnivore versus Mediterranean diets for LDL particle behaviour (NCT07462871).