What Does Your Child’s BMI Mean for His or Her Health?


It is difficult for parents to tell if their kids are growing healthy and reaching a healthy weight range. The BMI, a ratio of someone’s height and weight, is the best method for describing an individual’s nutritional health in a single number. An individual’s weight can easily be used to determine if his/her health is at risk.

According to the CDC, children aged 2 and above should be BMI screened. This article will explain how it is done and why.

Definition of BMI With Regard to Kids

The Body Mass Index (BMI) is a tool used to estimate how much body fat someone has based on their weight and height. However, when it concerns kids, the weight and height alone won’t be accurate just like adults. The major reason for this is since the fat percentage of children’s body continuously changes as and when they grow.

Bases of BMI – Age and Gender

Do you know healthcare professionals constantly give importance to the BMI of kids?

When healthcare professionals discuss a child’s BMI, you’ll usually hear their percentile rather than the number itself. They can help parents to understand how their child’s BMI relative to other children of the same age and gender. To calculate an individual’s BMI percentile, a healthcare provider or an online tool considers their age and gender as well as their own body mass index. This gives the child’s BMI percentile.

Classification of BMI Percentiles Based on Weight Categories

  • Underweight: below the 5th percentile
  • Healthy Weight: 5th percentile to the 85th percentile
  • Overweight: 85th percentile to the 95th percentile
  • Obese: 95th percentile or higher

Consulting With Pediatrician Regarding BMI

Many parents assume that if their child had a high BMI, their pediatrician would tell them. Parents are commonly unaware of the obesity problem amongst children in America until they undergo diagnosis and treatment at an early stage but that’s not always the case. If you are interested in what your child’s BMI percentile is, it may be beneficial to directly ask the doctor.

Some school districts have started to measure BMI of all students. The school then sends home a report card to alert parents to any weight issues. While some parents may dislike schools sending reports of their child’s BMI, experts say that the point is not to humiliate anyone. It’s aimed at parents to inform them about a life-threatening health condition in children.

Studies show that children’s BMI reports can be a helpful tool in combating childhood obesity. After receiving the report, nearly half of the parents with overweight children made some healthy lifestyle changes.

Difference Reasons for Childhood Obesity

Contributing factors to a child’s weight may include their family history, mental health issues, socioeconomic status, and lifestyle habits. Some of these are within your control and others aren’t.

Having overweight or obese parents means children are at an increased risk for obesity themselves because genetics has a part to play in maintaining weight, according to past research. To avoid child health issues, parents should ensure their children get enough sleep and live in a safe community. There are two factors that contribute to childhood obesity that you can control: eating habits and lack of exercise.

While it is important to keep in mind that convenient fast foods, processed foods, sodas, packaged snacks, candy, and sugary drinks can result in unhealthy weight gain when feeding your child. Drinking too much soda, eating unhealthy snacks that are high in fat and low in nutrients, and consuming very little nutrient-rich produce can put you at risk of obesity. Eating fast food more than once a week causes the risk of obesity to increase significantly for you and your family.

Ensuring your child gets enough exercise is important in warding off unhealthy weight gain. It can be difficult during this technological age, when people are able to use tablets, laptops, and other kinds of electronics. Watching tv and playing video games decreases children’s likelihood of getting exercise, which can cause them to gain extra weight. Your socioeconomic status may put your child at risk of being overweight or obese, but it is less controllable than other factors.

Parents in low-income communities often lack the education and resources needed to provide healthy meals for their children. If kids are allowed to visit corner stores or fast-food restaurants, they may buy unhealthy snacks or eat higher quantities of the less healthy meals than what could be typically afforded at home. They may also spend more time indoors if the neighbourhood isn’t safe for outdoor play.

To reduce your child’s risk for obesity, work with their pediatrician to identify healthy-eating and exercise strategies. The weight of children can affect more than just health issues. Children who struggle with becoming overweight may also experience stress, anxiety, and depression. Without a healthy way to cope, children who don’t know how to deal with emotions can develop relationships that are harmful.

Accuracy of BMI for Kids – Why It Is Important?

Athletic kids may fall into the overweight category when they are muscular. Experts generally consider BMI for kids to be a good measure of body fat, but athletic kids may have higher muscle mass and would be inaccurately assessed as ‘overweight’.

Although your child’s BMI percentile is important, it is only a piece of the whole picture. If their BMI isn’t in the healthy range, they need a complete weight and lifestyle evaluation with a pediatrician.

Is BMI Percentile Necessary? Can It Be the Best Method for Measuring Body Fat Among Different Kids

To calculate the BMI of an adult, take their weight (in pounds) and divide by their height (inches), squared. Then multiply by 730. However, because children and teens are still growing, their BMI percentiles are plotted on a graph. Each value is referred to as the BMI percentile.

The CDC recommends using BMI percentile to measure children and young people ages 2 years to 20. The height and weight of each child is taken at the pediatrician’s office, then a graph that compares your child’s number with those of others is created.

This is how to interpret the results, according to the CDC:

Underweight: less than 5th percentile

Healthy weight: 5th percentile to less than 85th percentile

Overweight: 85th percentile to less than 95th percentile

Obese: equal to or greater than 95th percentile

Tips for Getting the BMI Among Your Necessary Healthy Range

According to experts, children of various ages and weight categories should follow these healthy guidelines to maintain a healthy weight. It’s easy to remember them as 5-2-1-0 every day.

  • 5: Kids may not always eat their veggies, but it is critical for you to serve vegetables and fruits as part of a balanced meal every day. If they see a food many times, they are more likely to try it eventually. When offering snacks or meals, include fruits and vegetables.
  • 2: Reducing TV watching will provide the family with more time for activities such as spending quality time together. Kick the TV out of all bedrooms.
  • 1: It requires at least sixty minutes of activity from each family member to meet the minimum physical activity recommendations. Start small and keep adding if necessary. The goal is to have all those minutes be at least moderate activity, sweating after about 10 minutes.
  • 0: That’s how much added sugar adults should have per day. Juice drinks such as lemonade and fruit punch, sodas, tea, and coffee can all have added sugar. Stick to water and reduced-fat milk instead.

Do You Know the Normal BMI Range That Children Need?

The CDC’s guidelines state that a child’s body mass index is healthy when between the 5th and 85th percentile. Unlike adults, there is no specific BMI number range to stay within because a child’s BMI is presented as a percentile which takes weight, height, age, and sex into account.

Which BMI Is Thought as Overweight for Kids?

A child whose BMI falls between the 85th and 95th percentiles is considered overweight, while children at or above the 95th percentile (meaning their weight is higher than that of 95 percent of their peers) qualify as obese.

BMI of Kids – In Detail

BMI for children is sometimes referred to as “BMI-for-age,” because a child’s age is one factor that the calculation uses. As a child gets older, their body changes in different ways. It is best to compare children with other kids the same age and gender.

Calculating the BMI Percentile of Kids on Your Own

Before you can calculate your child’s BMI percentile, ensure that you measure the height and weight accurately.

To measure your child’s height:

  • Remove your child’s shoes, hats, and hair accessories.
  • Have your child stand against a flat wall with a bare floor.
  • Ensure that the stretcher’s legs are straight, and their arms remain flat on their bodies with level shoulders.
  • Have your child look straight ahead. Their line of sight should be parallel with the floor.
  • Your child’s body (head, shoulders, butt, and heels) should be flat against the wall.
  • Measure the height of a child using a flat surface, such as a ruler or piece of cardboard. Allow for some additional length so that when the item reaches to top of their head, it is nearly touching down.
  • Make a mark on the wall where the bottom of the flat surface touches the top of your child’s head. Then use a measuring tape to measure from the bottom of the floor to the mark.

To measure your child’s weight:

  • Place a digital scale on hard, even flooring for the most accurate measurements.
  • Place your child in the middle of a scale so that he/she has both feet firmly planted on it.
  • Record their weight as it appears on the scale to the nearest decimal point.

No matter what your starting point, everyone in the household can benefit from eating nutritious food and exercising. Sometimes we’ll intervene when a kid is above the 85th percentile in BMI because their weight is increasing at a fast rate.

Are There Any Other Options for Measuring the Body Fat of a Child

You can measure your child’s body fat in other ways, but some of these approaches require tools that are only available at a medical setting. If your children’s BMI percentile is in the overweight or obese range, your doctor may recommend additional measurements such as skinfold thickness. They even consist of 

  • Measuring skinfold thickness
  • Doing underwater weighing
  • Taking waist circumference
  • Using dual energy X-ray absorptiometry (DEXA) or a whole-body scan of bone and tissue

Although more accurate measures, such as a DEXA scan or using skinfold measurements is possible, BMI can be an adequate measure of body fat when these options aren’t available.

Research suggests a formula called tri-ponderal mass index (TMI) can help accurately measure a child’s body mass index percentile. It’s calculated by weight divided by height cubed. Researchers found TMI to be more accurate in measuring body fat levels in children and teens ages 8 to 17 when compared with BMI.

What Is the Health Risk Involved With Childhood Obesity?

Healthy eating and exercise are crucial for your child’s well-being, so you should encourage them from a young age. There are a variety of health risks that come from obesity in children. Some may take years to show up, while others can be seen much earlier. If obesity continues into adulthood, the risk for health complications goes up. Children with a body mass index percentile at the 95th percentile [or above] have a greater chance of maintaining obesity into adulthood.


So, when it concerns the proper diet and health of your children, you should make sure that you are following the correct BMI measurement. These numbers are the factors that determine whether your children are healthy and far away from childhood obesity.

Well, as parents, you should always be aware of the dangers involved in childhood obesity, especially the health complications it can bring on. As kids become fatter, they do have the risk of dying at an early age.


Saravavan Nadarajan (Vanan)

Vanan, fitness expert and leader at EzFit Singapore, specializes in holistic training—home-based, boot camps, and corporate fitness—with over a decade of industry experience.