Jessica Simpson is waging a war against her baby weight. Since giving birth to her first child, baby Maxwell, Simpson has been hitting the gym so that she can cash in on her $4 million contract with Weight Watchers. The 32-year-old singer had her first Weight Watchers weigh-in a couple days ago, and it seems like she has her work cut out for her.

How much weight did Jessica Simpson pack on as a new mom? Us Weekly is reporting that Simpson gained 70 pounds while pregnant with Maxwell. The next question is not if she can lose the weight, but if she can lose it in time. Sources revealed to Us Weekly that the new mom has to lose 20 to 30 pounds by the end of August or she won't be getting her pay day from Weight Watchers.

Simpson and her fiancé Eric Johnson welcomed first daughter Maxwell Drew Johnson on May 1, who weighed in at 9 lbs.13.oz. Now, as Simpson told People magazine, I need to do something about [the weight gain].

Acknowledging that she has been known to yo-yo diet in the past, Simpson revealed that she wants her diet plan to be a lifestyle. In late May she tweeted that she is so excited to be part of the Weight Watchers family.

While pregnant, Simpson has heartedly admitted that she did indulge in some cravings.  According to the Examiner, those pregnancy cravings included buttered PopTarts, fried Twinkies and cheesy mac. Now with a focused diet, the singer is reportedly limiting her food to fresh juices, veggies, and lean protein.

Is Simpson following her new diet strictly though? The singer just celebrated her 32nd birthday on July 10, and People magazine revealed her delicious party menu, which included gnocchi with brown butter sage and pappardelle with yellow tomato sauce, short ribs with basil pesto pecorino and chili, and pan-seared snapper for dinner. For dessert Simpson did decide to skip the birthday cake, but mini s'mores, pudding pies in mini mason jars and banana brown betties with ginger snap crumble were served.

Us Weekly reports that Simpson has asked her mom Tina to help keep herself in check, as friends of the singer explain that junk food has always been an issue. Another favorite indulgence of hers that has to get cut? A source revealed to the tabloid that Jessica Simpson loves margaritas, and had a few drinks post-pregnancy, but then stopped.

Simpson also reportedly has another major weapon in her weight-loss arsenal - Hollywood trainer Harley Pasternak.

Will Jessica Simpson be able to shed the baby weight in time to meet her big pay day?