From TNR, concerning Warren Buffett:
He confines himself to the diet of an eight-year-old, refusing to eat anything much beyond spaghetti, hamburgers, and grilled cheese sandwiches. Schroeder describes a bizarre scene in which Katherine Graham escorted Buffett to dinner at the Manhattan apartment of Sony Chairman Akio Morita. Japanese chefs served plate after plate that Buffett left completely untouched. “By the end of fifteen courses, he still had not eaten a bite,” writes Schroeder. “The Moritas could not have been more polite, which added to his humiliation. He was desperate to escape back to Kay’s apartment, where popcorn and peanuts and strawberry ice cream awaited him. ‘It was the worst,’ he says about the meal he did not eat. ‘I’ve had others like it but it was by far the worst. I will never eat Japanese food again.’“
Despite that pretty atrocious diet, Buffett appears to be relatively healyh at age 78. Maybe it’s due to his polygamous lifestyle.