By now, you've made serious progress toward your dream body. You've developed a healthy five-day-a-week gym habit. And you know which foods give you the fat-burning, energy-boosting effects you want. (Missed all that? Find parts 1 and 2 of our 12-week plan at marieclaire.com/powerup.)

The past two months have been easy. But now it's tempting to try the "too busy" excuse--and then there's your best friend's birthday dinner, and next, you're eating the leftover cake from the mail-room guy's farewell party. Just say no. Here's your two-step plan for bulletproofing your healthy habits—forever--against anything life throws at you.

About your trainer: Jillian Michaels
Jillian Michaels gets you results, whether you have 5 or 50 pounds to lose, with the smart strategies she's honed as a trainer on The Biggest Loser. Find out more about Jillian and her approach at jillianmichaels.com.

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