Jessica Simpson, 32, the new celebrity spokeswoman for Weight Watchers, says that when she was pregnant, she was "constantly hungry" and had a "big appetite."
"I let myself indulge in everything I wanted because it was the first time I was ever pregnant, and I wanted to enjoy it," says the singer, actress and fashion designer. "I wanted to be happy and eat what I wanted.
One of her favorite indulgences during pregnancy: macaroni and cheese.
On May 1, Simpson gave birth to her first child, 9-pound,13-ounce Maxwell Drew, her daughter with fiancé Eric Johnson, a former NFL tight end.
"I didn't realize it (the weight) didn't all come off with the baby," she says.
Simpson, who has been following the commercial weight-loss program with family and friends for a few months, will begin appearing in ads next week. The first one will give insight into why she joined Weight Watchers and her initial experience on the program.
Although she's not revealing her starting weight, Simpson said in March that she weighed 170 pounds when she posed nude and pregnant for the April issue of Elle magazine. She's 5-foot-4.
She says Weight Watchers hasn't given her a goal or a percentage she has to lose. "They want me to be healthy."
Weight Watchers tells members that a healthy weight range for a person her height is between 117 and 146.
She says the extra pounds are coming off pretty quickly, but she won't reveal exactly how much she has dropped so far. "I've lost weight every single week."
Simpson is "eating less of everything," but "I don't believe in completely depriving yourself."
Since joining Weight Watchers, she hasn't eaten macaroni and cheese. "It's better not to have it at the moment."
Still, she has to satisfy her cravings for chocolate. "I'm a woman who wants her chocolate. 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."
She's following the PointsPlus program, which assigns points to foods based on the amount of protein, fiber, carbohydrates and fat in them. Fresh fruits and most vegetables are zero points, so members can eat as much of those foods as they want. At first, she was eating about 34 points a day on the program, but after she weaned her daughter off breast-feeding, her points dropped to 28.
She has Weight Watchers meetings in her home with her mom, Tina, and several good friends - 14 people in all. By late August, they had collectively lost 160 pounds, she says. "It's nice to do it together and motivate each other."
Besides monitoring her food intake, Simpson says, she's doing about 60 minutes of cardio exercise a day, mostly walking, in preparation for getting in shape for the next season of NBC's Fashion Star. "My boobs are way too big to run at this point. I'm just walking."
She wears a pedometer to track her steps. She's walking about 14,000 steps a day but started at 10,000. A mile is roughly 2,000 to 2,500 steps depending on stride length. Many health experts recommend that people try to do at least 10,000 steps a day.
The pedometer helps her keep track of how active she is and allows her to minimize her workout time and maximize her time with Maxwell, she says.
Johnson is walking with her. "We take Maxwell out a lot. ... (Johnson) was really healthy when I met him, eating a vegetarian diet and very health conscious from being an athlete."
He has been supportive. "I have his support but not pressure. The fact that he loves me the way I am right now - we're set. He knows I want to feel better in my skin."
Simpson also is working with personal trainer Harley Pasternak about four to five times a week. She's doing short, simple body-toning workouts.
For years, there has been a lot of publicity about Jessica Simpson's weight cycling. "My weight has always been something that people like to comment on. I've gotten used to it. It'll start to get boring at some point, I hope," she says.
"Nobody wants to talk about their weight. For me, I have had to come to a place where I am comfortable with myself. I'm a mom now, and get to be a role model for this beautiful little girl."
Getting back into shape after pregnancy is challenging, but it's important for feeling confident and empowered as a woman, she says. "I feel like everybody can do what I am doing.
"I'm not a supermodel. My body is not bouncing back like a supermodel. I'm just your everyday woman who is trying to feel good and be healthy for her daughter, her fiancé and herself."