She's  as fat as she wants to be! Emmy-winning “Mike & Molly” star Melissa McCarthy – who got her big break in the hit comedy “Bridesmaids” – says she’s happy with her plus-size figure, and won’t slim down any time soon.

The 43-year-old actress was a perky size four to size six as a high school cheerleader, but now weighs in at a hefty 255 pounds.

“Who’s going to laugh at me running down the middle of the road waving my hands if I look like my girl Sandra Bullock?”

Melissa – who co-starred with Sandra in “The Heat” – recently told a friend. Melissa jokingly added: “Sandra and I have a deal. I won’t lose weight and take the skinny girl roles from her, and she won’t put weight on in order to steal parts from me!”

Former “Gilmore Girls” star Melissa says she packed on the pounds while pregnant with daughters Vivian, 7, and Georgette, 4. Her figure bounced back after Vivian’s birth, but Melissa didn’t lose the weight after delivering Georgette.

Despite that, Melissa believes her queensized figure makes her a better role model for her young daughters, said a source.

“Melissa hates how a lot of Hollywood moms are always putting the fear of fat on their kids – before they’re even schoolaged,” said an insider. “She says moms don’t realize they’re doing harm when they tell their daughters, ‘Put down that doughnut! Do you want to get fat?’”

Meanwhile, an expert says Melissa – who was once slammed as “tractor-sized” by a wasp-tongued movie reviewer – could be suffering from a syndrome called Metabolism Dysfunction.

“Melissa’s weight gain has a high probability of being caused by Metabolism Dysfunction, also known as the MD Factor,” Dr. Caroline Cederquist, medical director of, who has not treated Melissa, told The ENQUIRER.

“I would recommend that Melissa evaluate her diet to ensure she’s getting a proper balance of lean protein, complex carbohydrates and healthy fats. “Once you start gaining weight, your MD Factor becomes more severe, and is the reason many diets and increased exercise do not work for some people.”