A new review finds that while the carnivore diet may offer short-term improvements, weak evidence and new risks make long-term adherence a gamble for health.

study: Carnivore diet: A detailed review of current evidence, potential benefits, and risks. Image credit: Fascinadora / Shutterstock.com

In a recent review published in nutrientsresearchers determined the nutritional adequacy and health effects of the carnivore diet (CD).

What is a CD?

CD is characterized by minimal processing of animal foods such as fish, meat, eggs, seafood, animal fats, and full-fat dairy products, and is therefore also considered a low-carbohydrate/high-fat dietary pattern. CD is claimed to be associated with numerous health benefits, including weight loss, self-reported improvements in physical and cognitive performance, and reduced risk of developing chronic diseases such as diabetes, dyslipidemia, hypertension, and gastrointestinal disorders.

These claimed benefits are due to lack of exposure to anti-nutritional compounds (AN) found in plant-based foods, such as enzyme inhibitors, lectins, phytic acid, oxalic acid, tannins, thyroid hormones, and saponins. These are secondary metabolites in plants that can interfere with nutrient absorption.

Importantly, the absence of plant-based foods in CDs also impedes the intake of important phytochemicals. dietary fiberessential micronutrients. Furthermore, high intakes of animal products, particularly red and processed meat, have been consistently associated with increased cardiovascular disease, certain cancers, and mortality in broader epidemiological studies.

About reviews

Researchers in the current study reviewed the available literature to determine nutritional adequacy and health effects after CD consumption. Studies have reported that more than 10% of energy intake comes from plant-based foods; in vitro Studies, preprints, animal studies, review articles, conference papers, book chapters, and unpublished studies were excluded from the analysis. Search results were deduplicated and title/abstract screened to exclude irrelevant records.

The full texts of the remaining studies were analyzed and relevant data were extracted and synthesized. Overall, nine eligible studies published between 2021 and 2025 were analyzed, including five case studies, two surveys, one comparative modeling study, and one exploratory study. Five studies were conducted in Europe and four in the United States, but the definition of CD varied between studies.

Nutritional adequacy and cardiometabolic effects of CD

All but three studies excluded plant-based foods completely. Four studies explicitly focused on red meat, with two emphasizing high-fat meat intake and one emphasizing red meat intake.

In one study, CD was used as an elimination diet, but then transitioned to a ketogenic, meat-based pattern. Similarly, another study evaluated ketogenic CD variants. In one study, respondents ate a zero-carbohydrate diet that included primarily meat, including organ meats.

Three studies used questionnaires to investigate health status, dietary behaviors, and sociodemographic and anthropological characteristics. Two studies developed and evaluated theoretical diet plans based on nutrient intakes rather than a healthy eating index or dietary reference value (DRV).

Additionally, three studies evaluated the effects of CD on urological, gynecological, and gastrointestinal symptoms. One study compared gut function and diversity microbiome Between omnivore and CD.

Two studies classified multiple nutrients as deficient compared to DRV. More specifically, reported intakes were below the DRVs for thiamine, magnesium, iron, calcium, potassium, iodine, folic acid, and vitamins C and D.

Dietary fiber intake was below recommended levels, but vitamin A intake was above recommended levels, especially in diets high in liver-derived retinol. Four studies reported positive effects on self-reported or clinically observed disease course, in some cases allowing for discontinuation or reduction of medication. In one study, several laboratory parameters improved during CD, including triglyceride-to-high-density lipoprotein cholesterol ratio, C-reactive protein, and γ-glutamyl transferase.

Another study reported improved iron status and decreased fecal calprotectin in patients with inflammatory bowel disease. However, both studies also observed increases in total cholesterol (TC), platelet counts, and low-density lipoprotein cholesterol (LDL-C) levels. In individuals with metabolic disorders who initiated CD, triglycerides and glycated hemoglobin improved, but LDL-C and TC were significantly elevated.

In one case report, a patient’s health status deteriorated during CD and an unfavorable 24-hour urine profile was observed. One year after discontinuing CD, this patient no longer experienced kidney stones.

One study found no significant differences in gut microbiota diversity and function between omnivorous diets and CD. Motivations for adopting CD included perceived health benefits and, to a lesser extent, ethical considerations and perceived naturalness.

Many reported improved overall health, emphasizing the simplicity of their diet and the positive sensory experiences associated with consuming animal products. Of note, one study found that people who practice a zero-carb/CD lifestyle often have social conflicts outside of the CD community, such as difficulties interacting with medical professionals and tensions within their friendship and family networks.

conclusion

Continuation of CD may result in short-term health improvements, and these effects may be attributed to placebo responses, subjective perceptions, and ketosis-related metabolic adaptations. However, CD can increase the risk of cardiovascular and renal complications, micronutrient deficiencies, reduced fiber intake, and deleterious changes in lipid profile.

Limitations of existing scientific evidence on CD, such as lack of control groups, short intervention period, and small sample size, make it impossible to assess the long-term safety of CD. Therefore, long-term use is not recommended.

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