Q: My doctor recently told me that I'm overweight. I knew I'd gained a few pounds recently, but I had no idea the situation was this bad. I've never dieted before and don't know what to do. Where should I begin?

A: Dietthe word alone can inspire fear of drudgery and deprivation in just about anyone. But I have good news: You can lose weight successfully by assessing your current eating habits and making changes, rather than following a deprivation diet.

The health benefits you'll reap by making changes can be substantial. Even a small weight loss of 10 to 20 pounds can lower your blood pressure, improve your cholesterol levels, reduce your diabetes risk, and help to control blood sugar.

In order to lose weight, the first rule of thumb is to take in fewer calories than you use. You can do this in two ways: by eating fewer calories or by becoming more physically active. I recommend doing both togethereating less while increasing physical activity.

As a registered dietitian with more than 20 years' counseling experience, I've found some common areas that often cause people to consume excessive calories:

* Drinking too many liquid calories. It's not unusual for people to drink 1,000 calories or more every day. One large soda (32 ounces), for example, contains more than 300 calories.

* Skipping meals. So many people think that skipping meals saves calories. Unfortunately, people who skip meals usually overeat later and consume more calories than they would have if they'd eaten regular meals.

* Mindless eating. If you're nibbling here and there or eating while doing other activities, such as working, cooking, driving, or watching TV, you don't get the same pleasure from food as when you pay attention and truly enjoy your meals while you're eating them.

* Emotional eating. Do you reach for food when you're stressed, bored, or down in the dumps? Keep in mind that exercise is a much healthier way to manage stress, end boredom, and elevate your mood.

* Lack of knowledge about the caloric content of foods and beverages. One fast-food meal can quickly add up to over 1,600 calories (a quarter-pound cheeseburger, large fries, a large drink, and a dessert pie). Since it only takes about 3,500 calories more than your caloric requirement to gain a pound of fat, it's easy to see how all the extra calories can add up.

In fact, if you take in just 100 calories more than you use every day, you'll gain about 10 pounds in a year. The good news is that the reverse is also true: If you eat 100 calories less than you use every day, you can lose 10 pounds in a year. If you eat 250 calories less and use 250 calories more each day, you can lose about one pound per week. That's one less soda and 30 to 60 minutes of walkingyou can do it!

Keep in mind that setting realistic goals is also an important key to success, and it's always best to seek the advice of a registered dietitian, who can tailor an eating plan for you. To find a registered dietitian in your area, visit the American Dietetic Association's website.

Theresa Stahl has more than 20 years' experience as a nutrition consultant in private practice and works as a medical nutrition therapist in a variety of settings. In addition, she is a writer, speaker, exercise instructor, and nutrition advisor for Nubella.com.