Scarlett Johansson has been put on a diet by Gwyneth Paltrow.

The curvy "Lost In Translation" star has lost over 14lbs since she began working out with her "Iron Man 2" co-star in preparation for the movie.

A source said: "The pair have been doing daily workouts with Gwyneth's personal trainer Tracy Anderson. Scarlett is also staying away from carbohydrates."

The 24-year-old actress has reportedly decided to slim down amid fears she could lose out on movie roles to younger, more attractive actresses.

A friend told Britain's Star magazine: "Scarlett has always been happy with her curves, but recently she has been feeling pressure to lose a few pounds.

"She knows that she is up against tough competition from younger, prettier and increasingly skinner actresses."

Scarlett previously insisted she loved her fuller figure and felt no pressure to diet.

She said: "I don't need to be skinny to be sexy."

(China Daily/Agencies, April 8, 2009)