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Healthy Weight Center

Understanding BMI Calculation



Hi, I`ll be thirteen in two weeks. My BMI is 14.3. I weigh 33.2 kilos (73.19272 pounds). Is that severely underweight or not?

I have experienced bullying problems because of people thinking I`m anorexic and I would just like to find out once and for all.

I`m not a very fit person, by the way, if that`s of any help. I sprint very fast and that`s about all.

Thank you for your help. I appreciate your time.


According to the CDC (Center for Disease Control) pediatric growth charts, your BMI is less than the 5th percentile, meaning that over 95% of girls your age have a higher BMI. A BMI of 14.3 indicates that you are underweight. Being underweight places you at increased risk for certain conditions, such as fatigue, lack of energy, asthma, scoliosis, intestinal problems, abnormal menstruation, and increased susceptibility to infection.

First, you should have a check-up by your physician to be sure that there is not a physical reason causing you to be underweight. Your physician can also suggest how much weight to gain, based on your height and weight. Then you can modify your lifestyle habits to gain weight.

The most common cause of underweight in adolescents is a diet that does not supply enough calories to meet energy needs. Adolescence is a time of tremendous growth and these changes require a lot of calories and nutrients. If you visit the website,ChooseMyPlate.gov nbsp;you can enter your gender, age, and activity level, to find the number of calories needed per day, as well as the number of servings from each food group. You then would add another 500 calories per day to the suggested meal plan to gain weight at a rate of about one pound per week. Although you need to eat more calories, you don't want to eat foods that are high in fat and sugar with little nutrients. So choose nutrient-dense foods and beverages from each food group for 3 meals and 2-3 snacks a day.

In addition to eating healthy foods throughout the day, you also should exercise so you build muscle as you are gaining weight. A healthy diet and physical activity will make you feel more energetic and more positive about yourself!

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Response by:

Bonnie J Brehm, PhD, RD Bonnie J Brehm, PhD, RD
Professor of Nursing
College of Nursing
University of Cincinnati