Dietitians have asked Jenson Button maintain a diet like that of a caveman, and Button added that consuming loads of red meat is helping him stay fit.
The McLaren ace, who is in his 13th season in F1, is the sixth eldest on the grid behind the likes of veteran Michael Schumacher.
The fitness-mad 32-year-old says he has been working with dietitians, who have analyzed his blood group and discovered he functions best on a diet of red meat.
"I've been working with a fitness company who are really good and understand the body. They're the people who got me on the diet of having steak for breakfast with mushrooms and tomatoes," The Sun quoted Button, as saying.
"Looking stats, it shows I've improved. I'm a human machine. It works for me. People have different blood types, which makes a difference. I'm closest to a caveman," he added.
"I'm O+ which means you should have the caveman diet, which is basically steak for breakfast," he said.