is a pin-thin actress, but she says she doesn't get that way from depriving herself of good food.
"Luckily, I have fairly good genetics, but I do exercise," she told PEOPLE on Wednesday at The Hollywood Reporter
and Jimmy Choo's 25 Most Powerful Stylists luncheon in West Hollywood.
"I really do enjoy my food. I don't starve myself, because if I start denying myself, that's when I want to eat most of all. It's fine. I've pretty much always been this size. It's more about just staying in shape."
But she admits – as she grabs for a cookie at the Soho House-held event – that awards season put a little more pressure on her to maintain a flawless physique.
"It's so good to be able to eat [what I want] again," the Erdem-clad The Impossible
star said with a laugh. "I probably exercised more during [awards season] than I would normally. You're showing your arms. At my age you have to work a little harder, it's true."
The actress, 44, has raised her two little ones
Sasha, 5 and Kai, 4, to take on some of the same lifestyle habits as herself and partner, Liev Schreiber.
"The good thing is I always eat dinner early because I eat it with my kids," she says. "We travel a lot. I'm not going to go to Paris and push a salad around my plate. I'm going to Paris to have bread and treats and good wine."
"I like to live! We eat healthy, but if we're on the road, we're pulling over and getting what's available."