Your weight has been important since the moment you were born. Maybe you even know what your birth weight was. Most newborns weigh between 6 and 9 pounds, but some may weigh more and some less. But very quickly, a baby gains weight and everyone is glad about that because it means the child is growing bigger and stronger. As you get older, your weight is still important. It's something your parents and doctor will probably keep an eye on. When you go for a checkup, the doctor often will record your height and weight and compare it with what it was the last time you came in. The doctor wants to check that you are a healthy weight because weighing too much — or too little — can be a problem. But these days, being overweight is more common than being underweight. More kids and teenagers have weight problems than ever before. What Does It Mean? When people talk about being overweight or obese, they mean that someone has more body fat than is healthy. Everyone has some body fat, but too much fat can lead to health problems. Overweight kids might find it hard to get around and keep up with friends on the playground. They might be teased or feel bad about themselves. How Is It Measured? Someone can be underweight, at a healthy weight, overweight, or obese. There is no one perfect weight for a kid to be, but there are healthy weight ranges for kids based on height and gender (whether the person is a girl or a boy). Doctors use four categories to describe a person's weight: Underweight: A person weighs less than the healthy range for his or her age, gender, and height. Healthy weight: A person's weight is in the healthy range for his or her age, gender, and height. Overweight: A person weighs more than the healthy range for his or her age, gender, and height. Obese: A person weighs much more than the healthy range for his or her age, gender, and height. What Is BMI? But being overweight is more than a number on the scale. A taller kid naturally could weigh more than a shorter kid and not be overweight. That's why doctors use something called body mass index, or BMI, to help decide if a kid is overweight. BMI uses a kid's height and weight in a calculation that results in a number. The doctor plots that number on a chart. There are different charts for girls or boys. BMI estimates how much body fat the person has. Because muscle weighs more than fat, a muscular person can have a high BMI, but not too much body fat. Likewise, it's possible for someone to have a low or ideal BMI but still have too much body fat. You may get a BMI report from school, but the best way to understand BMI is to talk to your doctor. Why Do People Become Overweight or Obese? Most of the time, people have too much body fat because the body gets more calories (from foods and drinks) than it burns through physical activity, such as playing soccer or walking to school. Extra calories are stored as fat. The more extra calories a person eats, the more fat is stored. This happens very easily in modern life. People spend more time in front of screens, like TVs, phones, and computers, and less time moving around. We drive everywhere instead of walking or riding bikes. Fewer schools have gym classes every day; more kids play video and mobile games than active games like dodgeball. People lead busier lives so they have less time to cook healthy meals. We eat more restaurant meals, take-out food, ready-made food, and snacks. Weight problems can run in families. But don't let that discourage you from making changes that could help you be a healthy weight. Your habits — what kind of food and how much you eat and how much you exercise — can make a big difference. How Can Extra Weight Hurt Your Health? It's hard to feel good when your body has too much weight to carry. Being overweight or obese can make it harder to breathe and sleep. It can make a person feel tired and cause aches or pains. A weight problem also can make you feel embarrassed, sad, or even angry. When people feel bad, they may eat more because food can be comforting. This isn't a good idea, especially if someone is already overweight. Getting help is important because weighing too much can make you sick. Overweight or obese kids have a greater chance of getting diabetes and other health problems. And overweight adults have a higher chance of getting heart disease. How Can You Keep From Becoming Overweight? One of the best ways to stay at a healthy weight is to be active. You can join a sports team. Or, if you don't like team sports, try swimming, tennis, martial arts, or just playing in your own backyard. Jumping rope, dancing, and running around will get your heart pumping. Getting some extra exercise can be as easy as taking the stairs instead of the elevator or walking instead of having your parents drive you. Being active also means watching less TV and playing fewer video and mobile games. Eating healthy is another part of staying fit. Eat a variety of foods and get five servings of fruits and vegetables a day. Choose water and low-fat milk over soda and other sugary drinks. When it comes to high-calorie and high-fat foods, eat them only once in a while and, when you do, have smaller portions. What Should You Do? Talking to a parent is the best first step if you are concerned about your weight. Your mom or dad can make a doctor's appointment for you. The doctor may suggest ways of changing your eating and exercise habits. In general, kids don't need to diet. But a kid who is very overweight may need some expert help from a dietitian or a doctor who specializes in weight management. Together, along with your family, you'll come up with a plan that includes eating nutritious foods and exercising regularly. Helping Others If you have a friend or relative who is overweight, remember to be kind. He or she is probably well aware of the problem. Jokes or teasing will make the person feel worse. Encourage your friend instead by exercising together and sharing what you know about eating healthy foods. Back to Articles Related Articles Go, Slow, and Whoa! A Kid's Guide to Eating Right Want to eat healthier? It's easy when you learn the difference between Go, Slow, and Whoa foods! Read More Weight and Diabetes Being at a healthy weight is a good idea for everyone, but it's even more important for kids with diabetes. Read More Be a Fit Kid A lot of people talk about fit kids, but how do you become one? Here are five rules to live by, if you want to eat right, be active, and keep a healthy weight. Read More How Can I Feel Better About My Body? It's normal to wish you could change something about your body. Find out more about these feelings in this article for kids. Read More Learning About Calories You've probably heard about calories. Are they good or bad for you? Find out in this article for kids. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.