Scarlett Johansson has reportedly relaxed her gym routine thanks to her new-found “confidence” in her new relationship.

The stunning star was spotted flaunting her gorgeous curves on a Hawaiian beach with new man Nate Naylor recently.

Scarlett – who wowed in a bright blue bikini - usually maintains her svelte figure with 20-minute workouts and a “controlled diet”, according to sources.

However friends close to the beauty say she has relaxed her healthy eating plans since falling for the 38-year-old advertising executive.

“Her weight fluctuates so she keeps her eye on what she eats. She’s been slimmer, but it was hard to maintain and she’s got the confidence to embrace her sexiness in relationships – she loves eating out, or staying in with pizza and wine,” an insider told Closer magazine.

Scarlett was working out with trainer-to-the-stars Ramona Braganza before she began filming Under the Skin in Scotland last year.

The fitness expert says the 27-year-old actress prefers to avoid cardio exercise.

“Scarlett’s not a fan of running, but she got new sports shoes and it definitely helped,” she told the publication. “When you get new gear, it takes your mind of exercise.”

Ramona added that Scarlett followed a healthy “home-cooked” meal plan while shooting for the movie.