Willpower will get you only so far. To manage your weight over the long haul, you'll need to cultivate "wantpower," or the drive to eat healthy. How can you achieve a balance? "Devise a plan that takes into account your desires, not one that requires superhuman strength," advises nutritionist J.J. Virgin.

Find Your Real Inspiration "Having a true personal source of motivation--whether it's to lose 10 pounds for your high-school reunion, run your company's annual 10K, or eat healthier because of your family's history of heart disease--is the only way you'll succeed," says Virgin. She recommends writing down your objective, including why it's important to you, and placing it somewhere you'll see it every day, like on the fridge or at your desk at work. To make your resolution more manageable (read: less overwhelming), she also suggests setting smaller goals each week--for example, drinking eight glasses of water a day or having a serving of vegetables with each meal.

Toss out your trigger foods Serving yourself just one handful of chips or a small scoop of rocky road is a skill that takes a great deal of time to develop, says Virgin. So until you're able to put the container away every time, it's best to keep those tempting foods out of your line of vision. "If you have to leave the house to satisfy your craving, you'll be less likely to do it," she says.

Retrain Your Taste Buds You can learn to crave good-for-you foods, but it won't happen overnight. Start with "lateral shifts," says Virgin. For instance, instead of drenching your salad with ranch dressing, drizzle on balsamic or red-wine vinegar and a tablespoon of olive oil. If soda's your beverage of choice, try alternating it with a sparkling water flavored with a splash of juice. "Also, consider adding an extra fruit, a veggie-based soup, or a salad instead of taking something away completely," she says. "And eat that first, so you'll have less room for the higher-calorie foods."

Have A Game Plan For Going Out Cocktail parties and restaurant meals can seriously derail your diet. "Before you go, think specifically about how much you want to eat," says Virgin. For example, you might decide to have an appetizer, a single glass of wine, an extra serving of vegetables at dinner, and a few bites of dessert. "Being surrounded by so many choices and temptations can be really challenging," she says. "Having some preset guidelines helps cut through the confusion and prevent you from overindulging."

Follow The Three-Bite Rule If you truly want tiramisu, go ahead and have it, but limit yourself to a taste. "The trick," explains Virgin, "is to set aside that small portion first, and then give the rest away to your dining partners or ask the waiter to take it away."