President Donald Trump defended White House press secretary Sarah Huckabee Sanders on Monday, tweeting that a Virginia restaurant that had asked her to leave looked dirty.

Trump often eats at fast-food chains like McDonald's in part because of a "longtime fear of being poisoned," Michael Wolff writes in "Fire and Fury: Inside the Trump White House."

Trump's love for fast food is well-documented, with his go-to order being two Big Macs, two Filet-o-Fish sandwiches, and a large chocolate shake.

The president also reportedly believes that McDonald's is cleaner than many other restaurants.

President Donald Trump defended White House press secretary Sarah Huckabee Sanders in a tweet on Monday, saying that a restaurant that had asked her to leave over the weekend looked dirty.

Sanders said on Saturday that she was asked to leave The Red Hen, a restaurant in Lexington, Virginia, because she worked for Trump. One of the owners told the Washington Post that it was Trump's policies, which she called "inhumane and unethical," that had prompted them to deny service to Sanders.

"The Red Hen Restaurant should focus more on cleaning its filthy canopies, doors and windows (badly needs a paint job) rather than refusing to serve a fine person like Sarah Huckabee Sanders. I always had a rule, if a restaurant is dirty on the outside, it is dirty on the inside!" Trump tweeted on Monday.

Trump's concerns about restaurant cleanliness have been well-documented. His longstanding love for fast food is tied to a fear of being poisoned, Michael Wolff writes in "Fire and Fury: Inside the Trump White House."

Trump "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," Wolff reports.

The president's go-to McDonald's order was two Big Macs, two Filet-o-Fish sandwiches, and a large chocolate shake, according to former campaign manager Corey Lewandowski and top Trump campaign aide David Bossie.

Trump's regular McDonald's order. Hollis Johnson/Business Insider

"Like an amazing professional athlete who has a routine that they do all the time when they're ready for a big game," Trump "would consistently do the same things," Lewandowski told Business Insider's Allan Smith.

Trump has previously applauded fast-food chains for their cleanliness.

"One bad hamburger, you can destroy McDonald's. One bad hamburger and you take Wendy's and all these other places and they're out of business," Trump said at a 2016 town hall. "I like cleanliness, and I think you're better off going there than maybe someplace that you have no idea where the food is coming from."