How Kate Bosworth gained 10lbs

The 5-foot-5 actress, 24, who was "dangerously skinny at around 95 pounds, has gained 10 to 15 pounds since," estimates Beverly Hills nutritionist Jonny Bowden.

"Kate stopped partying, started working out more, eating a bit more and generally doesn't care about her weight so much because she¹s happy," a source close to the actress says, noting that no dramatic intervention was staged.

Adds a longtime friend, "Stress can take its toll, and last fall was just hard for her." (Bosworth and Orlando Bloom, 30, split in September.) "Kate is human. We all go through tough times."

"She's leading a happier, healthier lifestyle" with model beau James Rousseau, 26, says the pal.