Jessica Simpson, the latest face of Weight Watchers, is opening up about her pregnancy pounds and how she's fighting to take them off.

(Jon Kopaloff/FilmMagic/Getty Images)

During pregnancy, Simpson told USA Today, she was "constantly hungry" and had a "big appetite." Her go-to indulgence was macaroni and cheese.

"I let myself indulge in everything I wanted because it was the first time I was ever pregnant, and I wanted to enjoy it," the singer turned fashion designer said. "I wanted to be happy and eat what I wanted."

But since giving birth to her daughter, Maxwell Drew, May 1, the weight hasn't come off as quickly as she would have liked.

"I didn't realize it (the weight) didn't all come off with the baby," Simpson said.

The singer shocked fans when she posed nude, and pregnant, on the cover of Elle magazine in April. The 5-foot-4 star weighed 170 pounds at the time, she told USA Today.

Simpson will unveil her weight loss on the Sept. 10 premiere of Katie Couric's new talk show, "Katie." She'll also appear in Weight Watchers ads beginning next week. The pounds are coming off quickly, she said, adding, "I've lost weight every single week."

"I'm 10 pounds away from my pre-baby size," Simpson told Us Weekly.

To lose the weight, Simpson is following Weight Watchers' PointsPlus program which assigns points to foods. At first, she was eating foods that totaled 34 points a day but has since dropped to 28 points. She also has Weight Watchers meetings at home with her mom and close friends.

Along with the PointsPlus program, Simpson said she is eating less but not depriving herself. She hasn't eaten macaroni and cheese since starting Weight Watchers but she struggles to stay away from M&Ms.

"I'm a woman who wants her chocolate," Simpson said. "I allot myself a fun-size (bag) M&Ms. I eat one of those, and my craving is satisfied. I don't need the whole bag of M&Ms."

Simpson is doing 60 minutes of cardio a day. Her fiance, former NFL tight end Eric Johnson, goes on long walks with her and their daughter, Maxwell.

"My boobs are way too big to run at this point. I'm just walking," she said. She also does simple toning exercises with a trainer four to five times a week.

"Her waist is going in, and her thighs are getting smaller," Simpson's celebrity trainer Harley Pasternak told Us Weekly.

Simpson has been keeping her fans up to date on her weight loss via her Twitter account.

"Just bought all the girls in my @weightwatchers group pedometers to track their steps. 10,000 steps a day = 5 miles! Let's step it up!" she tweeted July 19.

Simpson insists that any woman can drop the pregnancy pounds and get in shape, just like her.

"I'm not a supermodel. My body is not bouncing back like a supermodel," she told USA Today. "I'm just your everyday woman who is trying to feel good and be healthy for her daughter, her fiancé and herself."