What is the carnivore diet?

Question: What is the carnivore diet, and is it safe?

Answer: The carnivore diet allows only meat, poultry, eggs, seafood, fish, some dairy products, and water. All vegetables, fruits, grains, legumes, seeds, and nuts are excluded, which is why it is sometimes called the "zero carb" diet.

The carnivore diet is an extreme member of the ketogenic, or keto, family of diets. Keto diets work this way: they supply too few calories from glucose and other sugars, so the body compensates by burning fat, which produces ketones as an energy source. Ketones enter the bloodstream and lower the blood's normal acid-base balance toward acidic, a state known as ketosis.

A typical keto plan draws roughly 70% to 75% of daily calories from fat, 20% from protein, and no more than 10% from carbohydrates.

The carnivore diet is the most ketogenic of all because it permits almost no carbohydrates. Its fat content is unspecified: it is simply whatever fat is contained in, or eaten alongside, the meat, fish, poultry, and dairy.

What are the risks of a carnivore diet?

Some keto diets can emphasize healthier mono- and polyunsaturated fats, but the carnivore diet cannot. Animal fat is mostly saturated fat, the least healthy type because it raises levels of LDL ("bad") cholesterol.

A drawback shared by all keto diets is their tendency to raise LDL cholesterol in both the short and long term. Other longer-term concerns, especially with the carnivore version, include increased risk of kidney stones, gout, and osteoporosis, and the very high protein intake can impair kidney function.

Because keto diets push the body to burn fat, any of them can jump-start weight loss. Even so, the carnivore diet is not one experts would recommend for that purpose.