Eating style
Carnivore diet
Eating only animal foods. What a carnivore diet involves, how thin the evidence is, and the known risks: no fibre, nutrient gaps and raised LDL cholesterol.
What it is
A carnivore diet is made up almost entirely of animal foods: meat, fish, eggs and, in some versions, dairy. Vegetables, fruit, grains, legumes, nuts and seeds are all excluded. That makes it close to zero-carbohydrate, so it overlaps with keto, but it goes further by removing plants altogether. There is no standard definition and no set macro split.
What the evidence shows
The largest study is a 2021 social-media survey of 2,029 adults who had followed the diet for at least six months. Most reported feeling better and few reported side effects. These were self-selected people describing their own health, with no comparison group, so the results cannot show what the diet does.
A 2026 scoping review found only nine human studies and rated the evidence as very limited: small samples, short durations and no control groups. It concluded that long-term adherence cannot be recommended. No randomised trial has tested the diet, and nothing supports claims that it treats or reverses any condition.
Known risks
Fibre comes only from plants, so intake falls to nothing against a UK recommendation of 30 g a day. The 2026 review flags likely shortfalls in vitamins C and D, calcium, magnesium and iodine. In the 2021 survey, the people who reported blood results had an LDL cholesterol level of 172 mg/dL, which the authors described as markedly elevated.
It also sits far outside guidance on meat. The NHS advises anyone eating more than 90 g of red or processed meat a day to cut down to 70 g, because eating too much probably raises the risk of bowel cancer. A carnivore day can be several times that amount.
A less extreme version
If what appeals is high protein, simple meals and fewer processed foods, a high-protein or low-carb pattern that keeps vegetables gives you those without removing fibre. There is no carnivore shelf on this page. If you still plan to try it, tell your GP first and ask for your blood lipids to be checked before and after.
Worth knowing
- If you have kidney disease, heart disease, raised cholesterol or diabetes, or take regular medication, do not start this without talking to your clinician.
- The benefits described online are self-selected reports. People for whom the diet went badly are less likely to post about it.
- Anything this restrictive can become a problem if you have a history of disordered eating.
Common questions
Is carnivore just a stricter keto?
In carbohydrate terms, yes: both are very low. The difference is that keto keeps low-carb vegetables, nuts and seeds, which supply fibre and several vitamins and minerals. Carnivore removes them.
Do you need supplements on a carnivore diet?
Probably, but nobody has tested which or how much. The 2026 review lists vitamins C and D, calcium, magnesium and iodine as likely gaps. That uncertainty is itself a reason for caution.
Sources
- Lennerz et al., Current Developments in Nutrition (2021): Behavioral characteristics and self-reported health status among 2029 adults consuming a “carnivore diet”
- Lietz et al., Nutrients (2026): Carnivore diet, a scoping review of the current evidence, potential benefits and risks
- NHS: Meat in your diet
- NHS: How to get more fibre into your diet
General information, not medical or dietary advice. Speak to a doctor or registered dietitian about your own situation.