Some foods are obvious no-no's: trans fats, processed food, white sugar, and excessive alcohol. Beyond that, though, everyone's body is different, and just because a diet book is on the best-seller list doesn't mean its program will work for you. "Some people thrive on a strictly high-protein diet, while others do great with fruits, grains, and beans," says Jillian. "You've got to ask yourself questions: When I eat meat, do I feel sluggish or agitated? When I eat fruit, do I feel satiated? Sometimes it takes a lot of trial and error to find the right combination of foods. And as a trainer, I've learned that you also have to take human frailty into account. If you can't bear the idea of giving up bread, choose whole grain and try to eat it with some protein." The protein, she explains, will slow the breakdown of the bread so its carbs won't cause your blood sugar to spike and then—as so often happens—crash, making you hungry again for something starchy.
7. Don't ever starve yourself.
Dieting means cutting calories, but less isn't always more. "One of the biggest misconceptions I've seen—including among the women I'm training on the show—is that the less you eat, the more weight you'll lose," says Jillian. "Maybe at first. But your body will think you're dying from lack of food, and your metabolism will adjust by slowing to a crawl." Most women should never eat less than 1,200 calories a day.
8. Outsmart your exercise excuses.
A routine you'll actually stick to has to have elements that appeal to you. If you love being outdoors, try hiking or walking somewhere inspiring—a beach, a park, a historic neighborhood. You also need to assess what motivates you. If you get competitive and push yourself more when you're around others, join a gym, take a class, or play a sport like tennis or softball. If you're good at finding reasons to skip a session, make a commitment to do something with friends, so you can't back out without letting everyone down.
9. Don't forget the weights.
The best fitness routine includes a combination of heart-rate-boosting exercise like jogging or stair-stepping and resistance training, which means either lifting weights or using gym equipment. Cardio burns the fat; resistance training creates shape and increases muscle mass—and the more muscle you have, the faster your metabolism runs, even when you're resting.
10. Start with baby steps.
Working out for 20 minutes a day isn't enough to get you buff, but "even that will start speeding up your metabolism," says Jillian. "Walk to a local restaurant during lunch hour, walk the dog, walk to the convenience store. The idea is to get moving."
Bob couldn't agree more. "Thinking, I can't get in shape because I don't have two hours a day to exercise is just another excuse for doing nothing," he says. "Start small, because small can only get bigger. Starting big means burning out, blowing out, getting hurt—another reason to stop."
Tip #11: Tough it out