Jennifer Aniston famously ate the same Cobb salad on the set of Friends for 10 years. That will never be the case for Hilary Duff. “I am not a creature of habit with my food at all,” Duff tells Us Weekly. “I’m always in the mood for something different. My new favorite addition to my egg is sriracha salt.” And while the Younger star keeps it healthy (her go-to dinner consists of roasted veggies and fish) she does occasionally splurge at lunchtime.

“I’ll usually eat a salad and possibly some french fries,” she says. “Gotta be a little naughty!”

The former child star also mixes up her workouts with a blend of hiking, dancing, boxing, yoga and strength training. Her favorite cardio machine: the VersaClimber. “I need my butt kicked because I’m not great at dieting,” admits Duff, 28. And she also needs to be able to chase after her 4-year-old son, Luca.

“Luca is at a great age where he wants to do things on his own, like getting dressed or building a Lego,” the Lizzie McGuire alum says. And though Luca has two famous parents (his dad is Duff’s ex, former NHL star Mike Comrie), the preschooler is no spoiled brat.

“He has to pick up his toys and bring his plates or cups to the sink. He helps me feed the dogs and helps carry bags in from the car,” raves Duff. “He’s not always in the mood to help, but my mom and dad always made us do those things, and you turn out better because of it.”

She adds, “He’s just started holding the door open for women and girls and it’s very cute. He says, ‘After you!’”

A Words with Friends fanatic, Duff can’t wait to introduce Luca to the mobile app’s educational version for students in grades 4 through 8. “I know Luca’s too young to play Words With Friends EDU, but I’m looking forward to when he’s old enough to play with me,” she says.

In the meantime, the actress and singer is happy to battle her pals: “It’s fun for me to play with my friends in L.A.,” she says. “It helps keep us connected when I’m filming in New York.”