This month, Kate del Castillo, the up-and-coming Mexican actress stars in La Misma Luna (Under the Same Moon), a role for which she gained 20 pounds.

Kate Del Castillo’s diet With a sensible diet that includes lots of fish and vegetables and a ramped-up workout routine, she was back to her old size in two months.

“When my friends ask me how I maintain my figure, I tell them, ‘Eat right, don’t be lazy, and get your butt to the gym,’” she says. Her other strategies for staying in shape:

Be an early bird “When my schedule’s tight, I work out early in the morning, when I’m still sleepy. That way, by the time I’m fully awake, my workout’s done! I also joined a gym near my home; the best gym is the one closest to you.”

Embrace your curves “When I had to gain weight for La Misma Luna, it all went to my butt, and even though I’m naturally small, I loved it. My definition of a healthy body is seeing the face of a girl who’s happy with herself.”

Kate Del Castillo’s workout “I typically run for an hour and swim for half an hour, but I also enjoy in-line skating, bicycling, and stair-climbing.

Sometimes I go to the beach and do circuits: Twenty minutes each of climbing stairs, running on the beach, then swimming. Mixing up my regimen makes me look forward to my workouts each time.” [via]