What is a Healthy BMI for a Teenage Girl? Advice from a Dietitian

Healthy eating for girls in their teen years can often be a challenge. In a time marked with many changes, it is important to be able to access adequate nutrition so that a sense of stability can be a common source of health for a young, growing girl. The Academy of Nutrition and Dietetics said it best when they gave this recommendation: “The best thing a young woman can do is to understand her own body and stay well by adopting a healthy eating style, getting regular physical activity and rest, and maintaining a healthy body image.” 

For teenage girls, a healthy or normal weight is considered between the 5th and 85th percentile for body mass index (BMI)-for-age. It needs to be noted that BMI is not a tool used to diagnose, but one that is used for screening nutritional issues.

In other words, the health of teen girls is measured by many factors, and BMI-for-age is one factor that can help identify the trends of nutrition and lifestyle over time. BMI-for-age can help to screen for weight-related concerns in teen girls, however other factors such as hormonal changes, interrupted patterns of sleep or eating, college life or other significant life changes, and body image can also play a significant role in recognizing trends or concerns. 

Read on to learn more about a healthy BMI for a teenage girl and how to use BMI-for-age to measure health status during adolescence. 

Image by Mike Von https://unsplash.com/@thevoncomplex

How to Calculate a Teen’s BMI

BMI is a teen’s weight in kilograms divided by the square of height in meters. In today’s world, the Center for Disease Control and Prevention (CDC) has made calculating BMI a lot easier and more accessible by providing a Child and Teen BMI Calculator to help patients and providers understand BMI and what results mean for an individual teen.

Weight and height change almost constantly during the teen years of growth, and so using this calculator tool can help to keep track of results in a quick and easy-to-understand way. When using this calculator, the results will explain the following: 

  • BMI
  • BMI percentile 
  • Healthy or unhealthy weight
  • What the results mean & What you should do
  • Why it is important to maintain a healthy weight
  • Tips for developing healthy weight habits
  • When and how to talk to your doctor or healthcare provider

Remember, a single BMI number or calculation is not sufficient enough to diagnose or predict overall weight status. Long-term monitoring of nutritional status is crucial for healthy weight management and overall wellness to be evaluated. 

When To Be Concerned About Your Teen’s Weight 

It is important to discuss weight trends over time with your teen’s doctor, dietitian, and other relevant health professionals. Your healthcare provider will likely give you a chart, BMI number, or BMI percentile by using a chart similar to the one shown in the image below. 

Image courtesy of the Centers for Disease Control and Prevention (click here to download )

To some, this chart may look like a tic-tac-toe board gone wrong — and that is okay. It’s part of the reason why doctors, dietitians, and other healthcare professionals spend years in school learning to interpret results.

The color-coded graphic shown in the image following this paragraph can be helpful in understanding your teen girl’s BMI and interpreting what the numbers mean when charted over time as your teen ages. 

Image courtesy of PennState PRO Wellness 

Results routinely falling in the red or blue areas may indicate malnutrition or nutritional concerns. If you aren’t sure how to calculate your teen’s BMI using these charts, be sure to ask about it’s importance and interpretation at the next appointment you have with your teen’s healthcare providers. They will be able to help you calculate your teen’s BMI and determine what steps may need to be taken to maintain or return to a healthy weight. 

Check out more information from my posts:

When to Seek Help from a Healthcare Provider for Your Teen’s Weight

If a teen is routinely falling in the underweight, overweight or or obese categories (less than 5th percentile or greater than 85th percentile), it’s important to discuss potential treatment plans with your physician and dietitian. 

Image courtesy of the Centers for Disease Control and Prevention

Generally, it is recommended that a teen girl have her BMI-for-age checked annually. Sometimes, a more often interval will be suggested by the teen’s healthcare provider if nutrition or weight management is a major concern.

Those in remission from eating disorders may require more constant care and evaluation as well to ensure that their recovery is going according to plan. It is important to schedule and attend appointments and check-ups at their recommended intervals for your teen as they assist the professionals in tracking growth patterns over time to determine if she is following a healthy trajectory.

Growth and development, including that of body, body image, and healthy habits is absolutely crucial in the teenage years and can have a significant effect on a teen’s degree of wellness into young adulthood and even later in life. 

What is a Healthy Weight for a Teenage Girl?

Healthy teenage girls come in all shapes and sizes, and optimal individual health does not have a universal “look” or “type”. A healthy weight does not come within a certain range of numbers either. For example, a teen girl who is an athlete might weigh more because she has more muscle mass.

This may result in her BMI falling in the overweight or even obese range. Does this mean she is overweight or obese? Probably not. It simply means that she falls outside the normal healthy range for her age, but she can still be healthy.

Other indicators that the health professionals evaluate can aid in coming to the final conclusion that she is growing healthily, even though BMI results raised a red flag during the screening. Since a healthy weight is individual to each person, it will look different for everyone.

Again, while this may seem like an overwhelming process at first, remember that your health professionals are here to help and make sense of all the numbers, results, and screening tools. You and your teen are part of a team that is aiming for the best possible health your adolescent girl can achieve. It’s important to ask questions and reach out along the way any time you have questions about BMI or weight management. 

What is Considered Overweight for a Teenage Girl?

Medically and nutritionally, the term “overweight” describes teen girls who fall between the 85th and 95th percentile of BMI-for-age. Anything above that is considered ‘obese’. It is important to note that there are many available interventions for teens to maintain or return to a healthy weight.

The category ‘overweight’ does not mean your teen is destined to become obese. Overweight simply is a screening term meant to alert the patient and provider to possible health trends. The description of overweight can also help in planning potential treatment plans and involving other health professionals to add their expertise to the team of providers serving your teen. 

BMI categories are not perfect. Like mentioned above, BMI does not take into account height and body composition so some teens with more muscle mass may fall into an ‘overweight’ or ‘obese’ category without having excess fat on their body. Speak to a healthcare provider to see if your teen’s BMI classification is a concern or not.

See Also: How Can I Tell if My Teen is Overweight?

Do Teen Girls Lose Fat During Puberty?

During the adolescent years, girls will see a great amount of growth in height and weight, especially when growth spurts and puberty changes take place. All of the following changes can be normal in the teen years: 

  • A period of rapid growth followed by a period of very slow growth
  • Growth spurts
  • Slow changes with puberty
  • Several changes occurring simultaneously 
  • Signs of maturity sooner
  • Signs of maturity later
  • Being bigger than other girls
  • Being smaller than other girls
  • Body shape changes
  • Wider hips
  • Increase in height and/or weight
  • Increase of fat in the buttocks, legs, and stomach
  • Body size increase
  • Feet, arms, legs, and hands growing in advance of the body (can produce a feeling of clumsiness) 
  • Increase in puberty hormones, potentially causing oily skin, sweating, acne, etc. 

Each teenage girl’s body is different, and as such these changes will happen differently for each girl. It’s important to keep in mind that each girl will go through puberty at her own pace. Girls often experience changes during puberty before boys of the same age.

During this time, teen girls also begin to develop the skills of thinking long-term, setting goals, and comparing herself with others. It is important to help a teen girl develop positive health habits and self-confidence in her body during this time so that she can enter adulthood equipped with those skills intact. 


Essentially, there is no “normal” BMI for a teen girl. The BMI that is healthy for your adolescent is the one that follows healthy trends for her age and aids in the development of nourishing habits each day.

Equipping your teen with the tools she needs to successfully fuel herself each day can reach beyond the plate and help her to develop healthy patterns for the future and for life. 

Related Questions

What is Considered Overweight for a 15 Year-Old? The best estimate for classification for teenagers who are ‘overweight’ or ‘obese’ is by calculating BMI. Overweight is teens who are between the 85th to 95th percentile on a BMI growth chart. Check with a healthcare provider if your teen falls into this category. Each teen is individual- they grow at different rates, hit puberty at different times, have different amounts of muscle mass, etc.

How Can a Teenage Girl Lose Weight? The best way for a teenage girl to get to a healthy weight is to develop healthy eating habits. Setting realistic goals is a great way to start working on bad habits. Ideas include limiting soda and processed foods, avoiding fad diets, drinking enough water, getting regular physical activity, and increasing fruits, veggies, and whole grains.

Check out my post for some tips: What is the Best Diet Plan for a 15 Year-Old?

What is the Best Way for a Teenager to Lose Weight? Learning to have a healthy relationship with food should be the focus of a teenager who wants to get to a healthy weight. Fad diets are not going to be helpful short term. Developing healthy habits will be the most beneficial to benefit a teenager for lifelong health.

How Can a Teenage Girl Lose Weight Without Exercise? It is possible to lose weight without exercise, but teenagers should always be including some type of physical activity into their day (except for certain health conditions). Keep trying new things until you find some activities that you like to do such as video workouts, rock climbing, hiking, swimming, jogging, soccer, ballet, football, tennis, frisbee, roller skating, etc.

Exercise is important for a growing teen and helps muscles and bones grow and strengthen.

See Also


E Ellis. How Many Calories Does My Teen Need?. Academy of Nutrition and Dietetics. 2020. Accessed at https://www.eatright.org/food/nutrition/dietary-guidelines-and-myplate/how-many-calories-does-my-teen-need 

E Ellis. Nutrition for Young Women. Academy of Nutrition and Dietetics. 2020. Accessed at https://www.eatright.org/health/wellness/healthy-aging/nutrition-for-young-women 

Healthy Weight, Nutrition, and Physical Activity. BMI Percentile Calculator for Child and Teen: Results. Centers for Disease Control and Prevention (CDC). 2020. Accessed at https://www.cdc.gov/healthyweight/bmi/calculator.html 

Stanford Children’s Health. Puberty: Teen Girl. Lucile Packard Children’s Hospital Stanford. 2020. Accessed at  https://www.stanfordchildrens.org/en/topic/default?id=puberty-adolescent-female-90-P01635 

Katherine Harmer, RDN

I'm a Registered Dietitian Nutritionist with a love for coaching others to success in their health goals, especially teenage athletes. Tennis was my sport of choice in high school. Now I'm a little bit older, a little bit smarter, and a little bit worse at tennis.

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