When you’re a kid, you can’t wait to grow up. As soon as you’re tall enough, you can ride the bigger rides at amusement parks. As soon as you weigh enough, you can stop riding in a car seat. Many childhood milestones are marked by reaching certain points of growth.

Today, most doctors help parents keep a close eye on their children’s growth. Not only do they want to make sure you’re growing properly, but they also want to make sure you’re not growing too quickly.

Given the many scientific studies that have linked weight with various health risks, doctors especially want to make sure your weight stays at a healthy level. Stepping on the scale isn’t the only way doctors can keep an eye on your weight, though.

Many doctors now routinely calculate your BMI in addition to your weight. BMI stands for body mass index, which is a calculation that uses your height and your weight to estimate the amount of body fat you have.

If your BMI is too high, doctors will likely be concerned. Having too much body fat can lead to various illnesses and other health problems. A high BMI may be a sign that you need to eat healthier foods and exercise more often.

Although you can roughly calculate your BMI if you know your height and your weight, it’s best to have a doctor do it for you. Since kids are still in the process of growing and age can be an important factor, too, your doctor will be able to calculate your BMI more accurately.

Based upon your BMI, you’ll fall into one of four categories: underweight, healthy weight, overweight, or obese. Based upon the category you fall into, your doctor can make recommendations for any changes you may need to make.

It’s also important to remember that BMI is only one factor to consider with regard to your weight and your health. For example, athletic kids who are very muscular might weigh more and have a higher BMI, yet not have much body fat either. Likewise, a nonathletic child might weigh less and have a lower BMI, but still have too much body fat.

If you have too much body fat, you probably don’t feel as good as you could. Too much body fat can make it harder to do many things, from sleeping to breathing to exercising. To feel your best, get your BMI checked by a doctor and follow all diet and exercise recommendations.