Pros
Current evidence for the benefits of the carnivore diet is taken from self-reported survey data rather than clinical research. Therefore, reported benefits should be treated with caution. People who follow the diet have reported high satisfaction levels and perceived improvements in their bodyweight, health and well-being.
People with diabetes have reported health improvements, with some noting decreases in medication use. People with bowel conditions also reported improvements in their gut function when following the diet.
The reported weight loss people experience (who are already overweight or obese) probably comes from the diet’s high-protein content and complete elimination of junk foods and sugar. The diet's simplicity may appeal to those of us who get overwhelmed by overly complex dietary guidelines. Its restrictive nature might be easier to follow for people who like clear rules and boundaries.
Cons
The carnivore diet presents several concerns that limit its appeal. The elimination of all plant foods raises issues around the adequacy of certain nutrients (e.g., vitamin C, folate, pyridoxine, fibre, calcium, and magnesium). Another potential worry is the lack of diversity of food, which is important for a healthy gut “microbiome”. A low diversity of the bacteria in your gut is associated with inflammation, obesity, gut, immune and mental health issues.
There’s also some debate around whether the high intake of animal (saturated) fat, with some studies reporting increases in the “bad” LDL cholesterol, which increases cardiovascular disease risk. The low fibre intake has been flagged as an issue for your gut health, and the high protein intake can possibly affect bone health and the function of some of your internal organs.
The restrictive nature of the diet also creates practical, social, and ‘psychological’ challenges. This includes the high cost of the high-quality animal foods, the limited variety and availability of them, and the potential affect social eating or dining out. While motivated people report high short-term adherence to the diet, the real-world sustainability of the diet for most people is questionable.
Bottom Line
The carnivore diet represents one of the most restrictive and unproven diets out there for improving your health and body weight. While there’s some data suggesting some people experience short-term satisfaction and perceived health benefits, the evidence is weak. There are also concerns about the nutritional adequacy of the diet, the cardiovascular risks and the unknown long-term safety of it.