RFK Jr. only eats meat, fermented foods. The carnivore diet, explained.

Health Secretary Robert F. Kennedy Jr. went into detail about his own eating habits during a conversation with USA TODAY's Extremely Normal show. So what exactly does he eat, and what do nutrition experts think about it?

“I am on a carnivore diet. I only eat meat or fermented foods,” RFK Jr. said.

The carnivore diet is an animal-based diet that allows meats, fish and small amounts of dairy, registered dietitian Jamie Nadeau previously told USA TODAY.

That means cutting out vegetables, fruits, grains, legumes, seeds and nuts, Harvard Health adds.

"It’s extremely restrictive and cuts out many, many nutritious foods that are proven by research to be health-promoting," Nadeau says, most notably adding that "the carnivore diet isn’t evidence-based, meaning there is no research to validate its claims."