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Mariah Carey -

One of this diva’s strangest habits included eating only purple foods for three days of the week after she gave birth to her twins. The diet included plums, grapes, and eggplant. 

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Tom Cruise -

So what's the secret of this A-lister? Bird feces. Known as the Geisha Facial, this Japanese beauty treatment was first popularized in Hollywood by Victoria Beckham.

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Jessica Simpson -

Despite her pearly whites, the singer has revealed that she brushes her teeth only three times a week. The reason? "Because my teeth are so white, and I don’t like them to feel too slippery, but I do use Listerine and I do floss every day. It’s really weird, but I have great breath."

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Mark Zuckerberg -

The Facebook founder reportedly wears the same t-shirt every day to avoid wasting time deciding on an outfit. They're not your regular old tees, however. His are specially ordered from Brunello Cucinelli, and reportedly cost between US$300 and US$400.

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Kate Hudson -

In order to look more awake in the morning, the actress dunks her face in an ice bath. That surely does the trick! 

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Christian Bale -

Unlike most people, the actor seeks to challenge superstitions on a daily basis. He enjoys walking under ladders, and his favorite number is 13.

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Lizzo -

Lizzo came clean about her hygiene habits, revealing that she doesn't use deodorant and says that she smells better as a result. 

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Katy Perry -

In contrast, Katy Perry brushes her teeth six times a day and carries several brushes with her at all times.

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Simon Cowell -

Cowell likes to feel in touch with nature and apparently, his favorite hobby is climbing trees. The famous judge has said that he does it daily and that it’s a ritual for him.

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Cameron Diaz -

Diaz has a cleanliness obsession, especially when it comes to doorknobs. The A-lister has a tendency to open doors only using her elbows, to avoid touching the germ-infested door handles.

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Johnny Depp -

Depp is known for collecting Barbies in his free time! He told Jimmy Kimmel that he started off using the dolls to test out the voices of some of his famous movie characters and playing with his daughter.

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James McAvoy -

The Scottish actor is known for saying “white rabbit” to the first person that he sees on the first day of each month. This old tradition is said to bring good luck. 

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Catherine Zeta-Jones -

So how does she get her Hollywood smile? Well, the actress is said to brush her teeth with a strawberry paste. She claims that it keeps her teeth white as she gets older.

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Megan Fox -

To calm here self down on a flight, Fox plays Britney Spears. She explained, "I know for a fact it's not in my destiny to die listening to a Britney Spears album, so I always put that on in my (headphones) when I'm flying because I know it won't crash if I've got Britney on."

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Chrissy Teigen -

Teigen has the strange habit of licking off the seasoning from her Doritos, and then putting them back in the bag. Let's hope the bag is only for her. 

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Kit Harington -

The actor travels with his lucky pen, which he has had since he was little. He also has to touch the outside of a plane three times before he gets in.

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Pamela Anderson -

It's hard to believe that this blonde bombshell doesn't look at herself in the mirror. However, she's known to have eisoptrophobia, which is a persistent fear of looking at reflective objects. Anderson also never watches herself on TV.

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Taylor Swift -

In an interview with Ellen, the singer revealed that she doesn't actively wash her legs in the shower because she shaves them. 

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Mark Wahlberg -

An early bird, the actor shared that he wakes up at 2:30 AM, prays, has two breakfasts, and then does two workouts. 

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Sandra Bullock -

Bullock is gorgeous as ever at 50, so what's her secret? Well, Bullock has revealed that she applies hemorrhoid cream under her eyes, which supposedly prevents wrinkles in the area. 

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Bill Gates -

Exactly seven hours of sleep, no more and no less, is the key to Bill Gates’ routine. Definitely a healthy habit! 

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Gene Simmons -

The rocker posted on Twitter that he puts ice in his cereal. Now, it's hard to understand what the point of this is. We all need answers.  

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Jake Gyllenhaal -

The actor isn't really into bathing. He told Vanity Fair, "More and more, I find bathing to be less necessary at times." This comes from his belief that not bathing can be helpful for skin maintenance and that our bodies are naturally self-cleaning. 

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Jennifer Aniston -

To protect herself from bad luck, the actress will only enter a plane with her right foot. And just like Kit Harington, she also taps the outside of the plane before boarding. 

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Eminem -

The rapper requires complete darkness when he sleeps, and when he’s traveling he ensures that the hotel staff black out the windows.

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Demi Moore -

This timeless beauty uses the age-old and largely discounted technique of leeches to detox. Would you dare?

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Serena Williams -

The former tennis player was known to wear the same pair of lucky socks during each match. She also tied her shoes the same way before every game.

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Elon Musk -

The business magnate would guzzle eight cans of Diet Coke and two cups of coffee every day. However, it’s said he’s kicked the caffeine bug. 

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David Beckham -

Beckham has a type of OCD where everything has to be in even numbers or in pairs. This includes socks in his drawer or even soft drinks in the fridge. 

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Stephen King -

The famous author eats a slice of cheesecake every day before he starts writing. Now that's the ultimate indulgence!

Sources: (Bright Side) (Vanity Fair) (Business Insider) (Diply)

See more: Stars who have dated their celeb friend's ex  

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