Credit: Jeffrey Mayer/

What's Taraji P. Henson's secret to staying slim?

Having just a few bites of her favorite treats -- and then cutting herself off.

"I love food, so I just try to eat as few calories as I can," the Curious Case of Benjamin Button actress told at the InStyle/DIC Diamond Fashion Show preview Thursday in Los Angeles.

Counting calories like Taraji? Get fitness tips and tricks from a celeb trainer.

But the 39-year-old star knows there will be a price to pay if she overindulges.

"Sometimes I can't help it. I'll have that slice of cheesecake and work out extra hard the next day," says Henson, who occasionally enlists the help of L.A.-based trainer Chariesse Griffin.

"I only work out with her when I'm training for something specifically, or if I need to bulk up," Henson tells Us. "Other than that, I know what to do to stay in shape."

Henson's next film, a remake of The Karate Kid, hits theaters in June.