Melissa McCarthy showed off her 50 pound weight loss this week while working on the set of her upcoming movie "The Boss."

The 45 year old Plainfield native first flaunted her slimmer figure on the red carpet for the premiere of her film "Spy." Her recent photos show she's looking slimmer than ever, which she credits from new diet regime.

According to Examiner McCarthy's weight loss secret was a low carb diet. "Melissa has been on a high-protein, low carb diet," a source revealed. "She's been making small changes and seeing big results."

McCarthy was motivated to lose weight after she realized that she needed to shed off a lot of pounds for her husband, Ben Falcone and daughters, Vivian and Georgette, Celebrity Health & Fitness reported.  "Melissa realized she wasn't being as healthy as she could be," an insider said. "She wants to set a good example for her kids and she wants to be around to become a grandmother too."

Aside from following a low crab diet, she also worked out and has been practicing Pilates.

McCarthy who launched her 'Seven7' clothing line in August wants to serve an inspiration for all women by showing her weight loss improvement and by showcasing her collection that fits for all women, including plus size women, which she understands the most after what she's been through.

Meanwhile, her dramatic weight loss appears to have helped her not only on her physical appearance but her outlook in life as well. Talking with Entertainment Weekly, McCarthy said she will totally be unrecognizable 25 years from now. She said, "I'm going to have so much work done. I'm going to just be unrecognizable."  

McCarthy, who plays Michelle Darnell in 'The Boss' and a Chicago teacher on the CBS show 'Mike and Molly,' is said to be starring in 'Ghostbusters' reboot.