Daughter can stay healthy while on a diet

Q. My 15-year-old daughter wants to go on a diet. How can I make sure she stays healthy while losing weight?

A. My first question is whether your daughter really needs to go on a diet. Before your teen starts any weight-loss program, talk with her pediatrician, who can help determine an ideal weight for your teen and give her guidance about dieting. Many people (teens and adults) view themselves as overweight when, by medical standards, they are not. They will not get any health benefits from losing weight -- though they may think they will look better.

If your pediatrician determines that your daughter does need to lose weight, remember that it matters how she does it. As nearly everyone knows, you lose weight by burning off more calories by your physical and mental activity than the calories you consume in your diet.

But what many people don't know is that reduced-calorie diets are not necessarily healthy just because they have fewer calories. For example, there are healthy and unhealthy fats and carbohydrates. If your daughter's low-calorie diet contains mainly unhealthy fats and carbs, that's not good — even if she loses weight.

Let your teen know that weight management is about long-term success. People who lose weight quickly by crash dieting almost always gain the weight back. The best weight-loss strategy is one that your teen can maintain for a lifetime.

Here are some simple guidelines to help you and your daughter to get things started:

• Eat a healthy breakfast every day. People who eat breakfast actually eat fewer calories during the day.

• Drink four to eight, 8-ounce glasses of water each day.

• Cut down or eliminate soda, juice and sports drinks.

• Switch from whole milk to low-fat or skim milk.

• Eat less, more often. Make sure your teen eats three balanced meals each day. Eating healthy snacks in between meals will help her eat smaller portions at meals.

• Eat foods from each food group every day, including whole grains, lean high-protein foods, and at least five servings of fruits and vegetables.

• Avoid fad diets and diet pills. Substituting a diet shake for a healthy meal will not give your teen the proper nutrients to grow. Avoid diet pills, which may have harmful side effects for growing teens.

• Exercise will burn calories and help your teen to stay fit and be healthy.

• Don't banish certain foods. Eliminating specific foods from your teen's diet is a sure way to make her crave them even more.

• Teach your teen to forgive herself if she does slip.

Many parents worry that if their teen diets, he or she will develop an eating disorder. Dieting alone does not cause eating disorders; they are very complicated and the result of many factors.

Make sure to encourage healthy eating habits rather than just weight loss. What really matters is having a healthy body, inside and out.

• Dr. Komaroff is a physician and professor at Harvard Medical School. Go to his website to send questions and get additional information: AskDoctorK.com.