October 3, 2021

Children grow really fast and their bodies change as they age. This can make it difficult for parents to determine if the child has a healthy weight. Body Mass Index or BMI is one of the most effective ways that help. 

It is a calculation that lets you find if an individual has a healthy weight. As recommended by the American Academy Of Pediatrics, kids aged 2 years and above should be screened regularly for BMI. 

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Adolescent BMI Calculator

BMI Calculator for Teenage Females

What is BMI for Kids?

Body Mass Index is an estimate of how much body fat is present. It is obtained by dividing the weight of a person in kgs by his/her height in metre squares. However, when it comes to kids, weight and height measurements are not enough to assess their health. This is because kids tend to have varying levels of body fat with growth. 

Doctors often estimate the BMI of kids starting at the age of 2 during routine checkups. As BMIs change too fast, they plot these measurements on growth-specific charts. Over time, the doctor can use the chart to track the child’s growth pattern and health. Though simple, body mass index can help identify if kids are gaining weight too slowly or too quickly. 

BMI in Kids – What You Should Know?

BMI is quite dependent on age and gender in kids. Their body fat levels change with age and girls have a different body composition right from puberty. 

Body mass index in kids is therefore not a direct measure of their body fat. Kids have a lot of muscle or a big frame, leading to a higher BMI though they may not have excess fat. Similarly, a child with a smaller frame can have a lower BMI but carry excess body fat. 

To deal with these discrepancies, it is important that BMI estimates are considered to be a trend rather than focusing on numbers. Anyone measurement can sometimes give a wrong impression of the kid’s growth. 

Though BMI is a great indicator of weight, it is not the perfect measure of body fat. In case you are concerned about the weight gain or loss of your kid, consult your doctor to find out if it is normal or not. 

You might have seen that healthcare professionals don’t use a plain number for the BMI of a child but rather a percentile. These values show how the BMI of a child compares to other kids in the same age group and gender. The BMI percentile is obtained by plotting a child’s BMI on a graph and comparing the numbers with other children of the same sex, height and age. 

BMI percentiles for kids are grouped into categories to suggest weight health.

● Below 5th percentile – Underweight

● Between 5th and 85th percentile – Healthy Weight

● From 85th to 95th percentile – Overweight

● Over 95th percentile – Obese

For example, if a six-year boy has a BMI percentile of 75th, it means he has a higher BMI than 75 out of 100 boys of the age 6 years. This is a healthy weight. 

How to Deal with Childhood Obesity?

While BMI offers a great way to assess the weight, paediatricians often consider multiple aspects to determine if the child has a healthy weight and appropriate growth pattern. They look at the growth charts, family history and medical history of the child. A lab test can also be advised to diagnose any underlying medical conditions. 

If a child has a low BMI percentile that falls in the underweight category, it can be improved by encouraging the intake of calorie-rich foods. This is usually better than increasing the meal portion of the child. If they are underweight because of some medical condition, treating the problem can improve their weight.

Children with BMI in the overweight or obese category should be paid attention to. You should work with your physician to identify the causes and solutions. Some parents understand that the weight of their child is a concern but others ignore it. While weight gain is not a problem in growing children, obesity should be controlled to prevent future health concerns. 

Childhood obesity is associated with a wide range of health risks. While some problems show up early, others can take years to expose. The risk of health problems rises if obesity continues to adolescence. Kids with a BMI percentile of 95 and above have a higher chance of being obese in their adulthood.

Immediate Risks in Kids

There are various health risks associated with high BMI in children. Here are some of these:


If weight gain and unhealthy eating habits are not checked, kids can develop type 2 diabetes at a young age. 

Sleep Apnea 

This condition leads to difficulty in breathing during sleep. Obesity can put children at a higher risk of developing this condition. If not treated, sleep apnea can cause heart and lungs concerns over time.


Kids with a higher BMI are more likely to develop asthma as compared to those with a normal range of BMI. 

Long-Term Health Risks 

High Cholesterol and Hypertension

These conditions put the person at risk of heart disease. Obesity in childhood can increase the chances of heart issues in later life. 


Excessive weight increases the pressure on joints, leading to concerns like osteoarthritis in later life.


Overweight and obese individuals might lack nutrients and suffer from a strain that increases their risk of developing cancer. 

Fatty Liver Disease

Fat deposits in the liver can cause this problem which leads to liver damage in the long run. 

Apart from these physical health problems, overweight kids can suffer from some mental health concerns. They are more likely to experience anxiety, depression and other problems. A number of mental illnesses can result from the stigma associated with obesity in adolescents. 

Lifestyle Changes in Kids

The best thing about kids is that the risks described above often get reversed when the child gets a healthy weight. However, it takes some effort from the entire family to improve the BMI of a child who falls in the overweight or obese category. Moreover, it needs patience if the child is too far from a healthy weight. 

Starting with small changes and working the way up to a healthy diet can bring significant results. Kids generally tend to eat what they find in the house so you can stock up healthy options like fruits and vegetables, whole grains, lean proteins like tofu, fish and chicken and low-fat dairy. See that you avoid sugary beverages, soft drinks, packaged snacks and processed foods like fries, chips, cookies and candies. 

Increasing the exercise time and limiting the screen time of kids is also important. Ensure that the child gets a minimum of 60 minutes of moderate physical activity every day. Reduce the restaurant visits for the family and focus on healthy meals cooked at home. This way, the child gets a healthy approach to his/her lifestyle which helps achieve a healthy weight.

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