LOS ANGELES, California (X17online) - Britney Spears is investing both time and money in a diet and fitness routine that costs around $23,000 a month, according to Closer UK.

Spears is shelling out nearly $4,000 a month for a private dance choreographer, $8,000 to work with the Pussycat Dolls' personal trainer James Van Daff, and $10,000 a month for a nutritionist and dietary supplements. In addition to her financial commitment, Spears has radically altered her diet and exercise habits - a source tells the magazine Spears has "changed the way she eats, trying to have only two thirds of what is on her plate. It's all about portion control and fresh food now."

Spears limits herself to 1,400 calories per day, tries to include as much steamed fish in her diet as possible and drinks a lot of water in place of Red Bull. However, the singer allows herself "cheat days," once a week where she is allowed to give in to her cravings and eat whatever she wants.

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