What is the evidence for and against a carnivorous diet?

From the Guidelines

The carnivore diet is not recommended due to the lack of robust evidence supporting its long-term safety and efficacy, and the potential for increased risk of heart disease, kidney stress, gut microbiome disruption, and cancer risk. The diet's extreme restrictiveness and lack of essential nutrients found in plant foods, such as fiber, antioxidants, and phytonutrients, are major concerns 1. While some anecdotal reports and preliminary studies suggest potential short-term benefits, the evidence is limited and inconclusive. In contrast, a well-balanced diet that includes a variety of whole foods, including plant-based options, is generally recommended for optimal health outcomes.

Some studies have suggested that a diet high in red meat may be associated with increased risk of chronic diseases, such as colorectal cancer and cardiovascular disease 1. However, other studies have found that the evidence for a causal link between red meat intake and chronic diseases is not consistent, and that the interactions between meat, overall diet, and health outcomes are complex and influenced by many factors 1.

A recent study found that a healthy eating pattern consisting of higher intakes of plant-based foods, low-fat dairy, and lower intakes of fried foods, red and processed meat was consistently associated with a lower risk of cardiometabolic health 1. Another study found that a vegetarian eating pattern was significantly associated with lower CHD mortality and incidence, but not CVD mortality or stroke mortality 1.

In terms of nutritional deficiencies, a diet that excludes plant-based foods may be at risk for deficiencies in certain nutrients, such as fiber, antioxidants, and phytonutrients 1. Additionally, a diet high in saturated fat and protein may pose risks for kidney stress and gut microbiome disruption 1.

Overall, while some individuals may choose to follow a carnivore diet for personal or philosophical reasons, the current evidence does not support its recommendation as a safe and effective diet for long-term health outcomes. Anyone considering this diet should consult with healthcare providers first, especially those with existing health conditions, and should undergo regular monitoring of cardiovascular markers, kidney function, and nutrient levels if they choose to follow it.

From the Research

Evidence For a Carnivorous Diet

• A study published in 2021 2 found that adults consuming a carnivore diet experienced few adverse effects and instead reported health benefits and high satisfaction, with improvements in overall health, well-being, and various medical conditions.
• The study also found that participants with diabetes reported benefits, including reductions in BMI, glycated hemoglobin, and diabetes medication use.
• Another study published in 2024 3 found that the carnivore diet met several national nutrient reference values (NRVs) for nutrients such as riboflavin, niacin, phosphorus, zinc, Vitamin B6, Vitamin B12, selenium, and Vitamin A.

Evidence Against a Carnivorous Diet

• The same study published in 2024 3 found that the carnivore diet fell short in thiamin, magnesium, calcium, and Vitamin C, and in iron, folate, iodine, and potassium in some cases, and that fibre intake was significantly below recommended levels.
• A review published in 2019 4 found that increased consumption of red meat and processed meat was associated with harm, including increased risk of cardiovascular disease and all-cause mortality.
• A review published in 2023 5 found that animal-food-centered diets may increase cardiovascular risk by increasing serum low-density lipoprotein (LDL) cholesterol concentrations, cardiovascular toll-like receptor (TLR) signaling, cardiovascular lipotoxicity, and serum trimethylamine-N-oxide concentrations.
• A cross-sectional study published in 2024 6 found that flexitarians, who consume a mostly plant-based diet with occasional consumption of meat and processed meat products, had more beneficial levels of insulin, triglycerides, total cholesterol, and LDL cholesterol compared to omnivores, and that a flexitarian diet may confer cardiovascular benefits.

Nutritional Considerations

• The carnivore diet may require tailored nutritional guidance and supplementation strategies to ensure adequate micronutrient intake and prevent deficiencies 3.
• A plant-based diet, on the other hand, may provide a more balanced mix of nutrients and reduce the risk of cardiovascular disease and all-cause mortality 4, 5, 6.