President Trump's deep fear of getting poisoned by his enemies caused him to caution the White House's housekeepers against ever touching his toothbrush, according to a new book about the early days of the Trump presidency.

Trump's phobia also fueled his culinary preferences, because the fast food he has long been rumored to enjoy is made in advance and can be picked up anonymously, veteran journalist Michael Wolff writes in "Fire and Fury: Inside the Trump White House." New York Magazine published excerpts of the book on Wednesday.

"Trump, in fact, found the White House to be vexing and even a little scary. He retreated to his own bedroom—the first time since the Kennedy White House that a presidential couple had maintained separate rooms," Wolff wrote in the book. "In the first days, he ordered two television screens in addition to the one already there, and a lock on the door, precipitating a brief standoff with the Secret Service, who insisted they have access to the room."

The president also enforced limits on what his housekeepers could clean or even touch, Wolff claimed.

"He reprimanded the housekeeping staff for picking up his shirt from the floor: 'If my shirt is on the floor, it’s because I want it on the floor,'" Wolff wrote. "Then he imposed a set of new rules: Nobody touch anything, especially not his toothbrush. (He had a longtime fear of being poisoned, one reason why he liked to eat at McDonald’s—nobody knew he was coming and the food was safely premade.)"

Trump even preferred to strip his own bed of its sheets and dictate when the sheets would be washed.

His unique habits included having a regularly-scheduled dinner with his former chief strategist, Steve Bannon, at 6:30 p.m. or placing phone calls to his friends from the comfort of his bed while eating a cheeseburger, Wolff wrote.