Future of beef · All-meat eating

Carnivore diet

The carnivore diet is an eating pattern that excludes all plant foods and relies on meat, fish, eggs and sometimes dairy. It has grown through social media since the late 2010s; as of 2026 there are no long-term controlled trials of it, and the evidence available consists mainly of self-reported surveys and case reports.

Also known as: Dieta carnívora · Chế độ ăn toàn thịtLast reviewed 22 Oct 20264 sources

Zero carbohydrate, mostly beef

The carnivore diet (also "zero-carb" or "all-meat" diet) is an extreme form of low-carbohydrate eating. Followers eat only foods of animal origin, typically beef, other meats, fish, eggs, animal fats and, in some versions, cheese and butter. Fruit, vegetables, grains, legumes, nuts and seeds are excluded. Beef, especially fatty cuts such as ribeye, is often the staple.

Because carbohydrate intake is close to zero, the diet is usually ketogenic: the body shifts to burning fat and producing ketone bodies for energy. It differs from conventional ketogenic diets, which are used clinically under supervision for some forms of epilepsy, in excluding all plant foods, including low-carbohydrate vegetables.

This article describes the diet and the state of the evidence. It is not medical advice. Anyone considering a major dietary change, particularly with a medical condition or medication, should consult a qualified health professional.

A survey of 2,029 adults

The largest published study is a 2021 online survey by Lennerz and colleagues of 2,029 adults who had followed a carnivore diet for at least six months. Participants reported high satisfaction and improvements in well-being, and those with diabetes reported lower blood sugar and reduced medication. The authors noted that LDL cholesterol was, on average, substantially elevated among respondents who reported it.

The study's limits are important and were stated by its authors: participants were self-selected from social-media communities, results were self-reported, there was no control group, and people who had abandoned the diet or had bad experiences were unlikely to take part. A survey of this kind can generate hypotheses; it cannot show that the diet causes the reported effects or that it is safe over the long term.

Short-term weight loss and improved blood-sugar control are consistent with what is known about low-carbohydrate diets in general, which have been studied in controlled trials. Those trials, however, did not exclude all plant foods, and their results cannot be transferred directly to an all-meat diet.

Cancer, cholesterol, no fibre

Cancer risk. In 2015 the International Agency for Research on Cancer (IARC) of the World Health Organization classified processed meat as carcinogenic to humans (Group 1) and red meat as probably carcinogenic (Group 2A), mainly on evidence for colorectal cancer. The risk rises with the amount eaten. The World Cancer Research Fund recommends limiting red meat to about three portions a week (roughly 350–500 g cooked) and eating little or no processed meat. A diet built on meat typically exceeds these amounts many times over.

Cardiovascular risk. Diets high in saturated fat raise LDL cholesterol in many people, and LDL is an established cause of cardiovascular disease. Individual responses vary widely.

Fibre and micronutrients. The diet contains no dietary fibre, which is associated with lower risk of colorectal cancer and cardiovascular disease and supports gut microbiota. Fresh meat contains only small amounts of vitamin C; organ meats and the near-absence of carbohydrate may reduce needs, but the question has not been studied adequately. Folate, magnesium and potassium intakes can also be low depending on food choices.

Other effects. Reported short-term effects include constipation or diarrhoea, fatigue during adaptation and, in people with kidney disease, concern over high protein loads.

No dietary guideline recommends it

No national dietary guideline or major medical body recommends an all-meat diet. Guidelines in most countries, and reference frameworks such as the 2019 EAT-Lancet Commission, recommend diets based largely on plant foods with moderate amounts of animal foods. These guidelines differ in detail, and some are debated, but they agree on the inclusion of vegetables, fruit, legumes and whole grains.

Questions only trials can answer

Whether the improvements reported in surveys persist, whether they are due to the absence of carbohydrate, to weight loss or to the exclusion of ultra-processed foods, and what the long-term effects on cardiovascular disease, cancer and mortality are. Answering these questions would require controlled trials with follow-up over years, which had not been published as of October 2026.

Frequently asked questions

Sources

4

1. Lennerz, Belinda S.; Mey, Jacob T.; Henn, Owen H.; Ludwig, David S. "Behavioral characteristics and self-reported health status among 2029 adults consuming a 'carnivore diet'." Current Developments in Nutrition 5, no. 12 (2021): nzab133. doi.org/10.1093/cdn/nzab133
2. Bouvard, Véronique; et al., on behalf of the IARC Monograph Working Group. "Carcinogenicity of consumption of red and processed meat." The Lancet Oncology 16, no. 16 (2015): 1599–1600. doi.org/10.1016/S1470-2045(15)00444-1
3. World Cancer Research Fund / American Institute for Cancer Research. Diet, Nutrition, Physical Activity and Cancer: a Global Perspective. Continuous Update Project Expert Report, 2018. www.wcrf.org
4. Willett, Walter; et al. "Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems." The Lancet 393, no. 10170 (2019): 447–492. doi.org/10.1016/S0140-6736(18)31788-4

Related