It was such an odd moment for me: I was at a bar a few months ago with some friends and, for whatever reason, the subject turned to weight issues. (Not, by the way, a subject I usually choose to chat about over drinks.) I told some story about my chunky childhood and this guy I hadn't met before, a friend of a friend, said he never would have pegged me as a person with a weight problem. That definitely threw me.

Here's the skinny: Since I was 9, weight has been an issue for me. Over the last 23 years, I've become quite the expert at shedding pounds. In fact, I've done it more times than I care to mention through methods ranging from the sensible to the utterly ridiculous. (Let's just say a weeklong banana-and-vanilla-ice-cream-only diet is not as much fun as it sounds.)

As for keeping the weight off? In that arena, I was a fumbling amateur. I would get bored. I would get frustrated. I would, well, give up, and my weight would creep up. Then, in 1999, I joined the weight-loss program at the (now-defunct) Theodore B. VanItallie Center for Nutrition and Weight Management at St. Luke's-Roosevelt Hospital Center in New York City. The dietitians there helped me realize that it was time to stop futzing around (and making myself miserable) with one-size-fits-all weight-loss plans; I needed an approach that allows a custom fit.

Now 45 pounds lighter, I'm confident (on most days) that I'll be able to maintain that weight loss for the long haul. But I also realize that I can never really let my guard down.

"It's hard, hard work in a society that gives this kind of work short shrift," says former VanItallie Center director Cathy Nonas, R.D., author of Outwit Your Weight: Fat-Proof Your Life With More Than 200 Tips, Tools & Techniques to Help You Defeat Your Danger Zones (Rodale Press, 2002).

Following are a variety of tips and tactics you can put into play to help you get to -- and maintain -- your goal. Oh, just one big (and heavy) thing you need to keep in mind: "When people will not acknowledge their responsibility, no other tool will be helpful," says Madelyn Fernstrom, Ph.D., director of the University of Pittsburgh Medical Center Health System Weight Management Center.

Weight-loss success really begins when you are willing to take an honest look at your eating and exercise patterns and vow to make the necessary changes. If you have confidence that you can do it, you're on your way.

1. Play by the numbers.

No matter where it comes from, a calorie is a calorie, and it takes 3,500 calories to gain or lose a pound. Want to shed a perfectly respectable 1 pound per week? Carve 500 calories off your day by thinking through your food choices and upping your exercise. "It's easier both to walk for an hour and burn off 300-400 calories and to cut out 100-200 food calories than to focus on food restriction alone," Fernstrom says. If you want to add ingredients like soy or olive oil to your diet, you have to make substitutions and fit them into your food plan. Don't just tack on extra calories, she says.

2. Don't cheat your body.

When deciding how to spend your calories, experts agree your body performs best when you include all of the macronutrients -- protein, carbohydrates and fats -- in your diet. The American Dietetic Association recommends a diet that contains 30 percent calories from fat, 55 percent from carbs and 15 percent from protein.

3. Learn how to control food cravings.

"Cut out the specific items in the category [for example, carbs] that are giving you difficulty without cutting out the nutrition," Nonas says. Give pretzels the heave-ho but don't dismiss whole-grain breads. Has ice cream become a problem? Instead, snack on single-serving portions of yogurt. "Spice up meals by adding a new vegetable, trying a new recipe each week or adding a new color fruit," suggests Danae Blair, R.D., a nutritionist based in New York City.

4. Keep careful track.

Carefully monitor what you eat and how much you exercise. "So many people tell me they walk all over the place," Nonas says. "Then you put a pedometer on them, and they do an average of 4,000 steps a day when it's suggested that we do no less than 10,000 steps daily."

When it comes to food, it's not the drinks or desserts that do you in as much as mindless eating, Nonas says. To help account for all those calories (and to keep yourself honest), measure your portions, write down what you eat in a food record after each meal, and track your daily steps using a pedometer. If you don't want to track everything every day, try keeping records one week out of every month just so things don't get fuzzy.

5. Set your own rules.

Think of it this way: "If you're a vegetarian, you're not going to eat the meat no matter where you go -- to a party, restaurant or a buffet," Nonas says. The best way to achieve that same clarity when you're trying to lose weight is to set some rules. Find yourself snacking on cereal at night? Make an only-for-breakfast rule. If you slip, no cereal in your house for a month! Tend to dive into the breadbasket as soon as the waiter brings it around? Set a one-starchy-carb-per-restaurant-meal rule. If you want the bread, tell yourself before you head out that you'll skip the potato or pasta that comes with your meal.

Nonas says that those on a weight-loss plan should eat no more than six servings of (preferably high-fiber) grains per day. On maintenance? Eleven is the magic number. (A serving of carbs is one piece of bread, and a serving of grains is 1/2 cup of whole-wheat pasta.) To make the rules official, write them down.

6. Step up to plan B.

Sudden cold snap hit and your walking partner bailed on you? Join a gym, take a new exercise class or purchase some inexpensive at-home workout tapes or gear. Weight loss slowed and you're frustrated? To avoid boredom, shake things up. Register for a healthy-cooking class or go vegetarian one day a week.

What to do when the scale won't budge

Around the six-month mark, even the most diligent calorie counters plateau, according to Cathy Nonas, R.D., author of Outwit Your Weight: Fat-Proof Your Life With More Than 200 Tips, Tools & Techniques to Help You Defeat Your Danger Zones (Rodale Press, 2002).

"Is it physiological? Is it mental? It's probably a little bit of everything," Nonas says. "You feel good about yourself, you've lost weight, so maybe you get a little casual or careless, even though you're not doing anything crazy like eating a box of cookies. The other possibility is that your body may need to slow down and adapt to the changes in weight," she adds.

- First, figure out if you've hit a true plateau. "I've known people who thought they were plateauing when they were just losing half a pound a week," Nonas says. "When somebody plateaus, they can continue to lose fat even though they don't lose weight. One good reality check is to ask yourself if your clothes feel looser."

- If you're really doing everything you can to lose weight and you're still not making any progress, "pat yourself on the back for having lost [weight] and kept it off," and then make some subtle changes, Nonas says. "Just make sure you're clear about the changes so you can track your progress," she adds. Try eating a healthier lunch a few times a week or give a new class at the gym a try. "It may take a while but, eventually, you'll move ahead again," Nonas says.

- If you're already eating healthfully and exercising sufficiently, recognize that you may have achieved a healthy weight that's ideal for you. Celebrate the progress you've made and appreciate what your healthy body can do. At the point where you are already eating healthfully and exercising regularly, it's foolish to continue focusing on what you weigh. Instead, be vigilant and nurture yourself with healthy habits.