The singer shows off her new bob hairstyle and super-toned body in the music video for worldwide hit "Umbrella."
Rihanna admits she owes her fantastic figure to grueling exercise and a strict no-carbs diet.
She said: "I like carbs but at the end of the day, carbs are the enemy. It wasn't so much losing weight as being fit and toned and healthy. I just didn't feel great."
"Now I'm working out and trying to eat healthy. That's making me lose weight without even thinking about it."
Rihanna, 19, has been giving special attention to her curvaceous butt.
She added: "I work with a trainer. We work on the arms and we work on my butt, because I love my butt. But my legs are my main focus. I'm obsessed."
The singer's fitness regime includes a cardio workout, weight training two to three times a week and a specially devised eating regime.
Rihanna has been eating lots of carrots, lettuce, cucumbers and egg whites,snacking on fruit all day and drinking plenty of water to achieve her desired body.
