In “Eclipse,” Bryce Dallas Howard may play villainous vampire Victoria – but when it comes to dessert, the star says she’s more like a wolf.

“Indulge every now and then. It’s good for the spirit! I literally wolfed down three pieces of chocolate cake in celebration of my brother’s graduation an hour ago,” she told the July issue of SELF Magazine. “Tomorrow I will be better behaved, but I don’t regret a single bite!”

However, the svelte star said filming “Eclipse” helped her kick up her fitness routine.

“Everyone got quite fit during ‘Eclipse,’” she said, adding that the tough part was keeping it up after. “One method that I am beginning right now that I love is a ‘group fitness club’… we have created a system of group rewards… and group penalties if one of us slacks off.”

Having friends involved keeps her from taking it easy, she added.

“I realized that in regards to fitness it is often so much easier to let myself down than to let someone I love down,” Bryce said.

Beyond the gym, the actress also shared some of her beauty tips with the mag.

“I really feel like a good haircut is critical. I will spend money on a good cut, just so that I only need to get my hair cut twice a year, because if it is good — it will grow out beautifully,” Bryce said. “I also drink tons of water, and try to dry brush my skin before showering – it’s detoxifying. And Elizabeth Arden hour 8 hour cream as a lip gloss is fantastic.”

She’ll put her good looks to evil use in “Eclipse,” due June 30, as Victoria, a vampire out for revenge against Bella (Kristen Stewart).

“I had read all the books before I saw ‘Twilight,’” she said. (Rachelle Lefevre played the role in “Twilight” and “New Moon” before Bryce stepped in.) “So I am what could be described as a ‘Twi-hard.’ I found the character of Victoria to be quite complex. On the one hand she is of course, a blood-thirsty vampire, but on the other she is a grieving widow, seeking vengeance. Both of those traits lend themselves to a pretty dangerous creature, which I must admit was very fun to play!”