Amber Riley at the 2011 Golden Globes (left) and at the NAACP Awards on Feb. 17, 2012 (right).
Mario Anzuoni/Reuters/Landov; Jordan Strauss/Wireimage
By Thailan Pham
02/22/2012 AT 08:15 PM EST
Glee star Amber Riley turned heads when she stepped out in a blue Theia sequin gown – and showed off a slimmer silhouette! – at the NAACP Image Awards on Feb. 17.
The actress tells PEOPLE she decided to revamp her eating habits last July after chronic stomach pains drove her to the doctor.
"I decided I was going to make a change and eat healthier," says Riley, 26, who cut out the fast food and burgers that she says "were attacking my stomach."
After seven months of sticking to a new diet and exercise plan, she has hit a weight loss milestone: "I dropped two dress sizes!"
The red carpet darling also says that getting dolled up for events is a little easier now. "I'm a lot more comfortable in dresses, especially gowns," she says.
On set, Riley's trimmer figure has been causing quite a stir in the costume department. "We had to revamp the wardrobe," she says. "They bought a lot of new clothes for me and we have to take in a lot of my pants and dresses."
But no matter what size she's wearing, the actress has always been a body confident role model. "I've always been comfortable with my size," says Riley. "I just decided it was time to get healthy."