"I've always been honest about everything," the reality star, 37, tells PEOPLE. "I wanted to do a mommy makeover. I had done it after my oldest child. I really needed to just treat myself, and I'm happy about it!"
Vaughn said the weight came off slowly even after surgery, in part due to an issue with her thyroid. To really drop the lbs., the mom-of-two began practicing portion control when it comes to her diet.
"I watch what I eat, and I'm into snacking now," she says. "I used to just eat maybe once or twice [a day] – breakfast and then dinner, maybe skip lunch. But now I try to snack, have some nuts, have some yogurt."
She's also cut down on eating one of her favorite foods – fried chicken.
"There are still times that I want it, but I have to watch it," says the former Moesha star. "Instead of getting three pieces, I'll have one piece and walk away."
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Vaughn has also began making exercise a regular part of her lifestyle.
"I've been working out and taking care of me so I can have energy for my kids and work," she says. "I put my music on and I just walk for 30 to 45 minutes. I'm very appreciative now that my body is responding to the workouts and the diet, so I just have to keep on moving."
Vaughn says the best part of her weight loss transformation is "just being happy. I feel better and I feel healthier."
Hollywood Divas' two-part finale special begins airing Sept. 9 at 10 p.m. ET on TV One.