Los Angeles:  Actress Kristen Stewart has reportedly put boyfriend Robert Pattinson on a diet. The 22-year-old actress has apparently ordered him to hit the gym and lose some of the weight he gained during his time off. The duo met on the sets of superhit vampire saga "Twilight" and fell in love with each other.

"Robert's put on nearly 10 pounds eating cheeseburgers and drinking beer while he's not been working," a source told to the website.

"Kristen's told him to pull himself together. He hates the gym, so she's encouraged him to take up paddle surfing to try and work off the excess calories," said the source.