BMI for children, What is healthy? Calculator and read more
“Is my child healthy?”
“Is my son growing at a normal rate?”
“Could there be a chance my daughter is underweight?”
These may be just a few of the questions you’ve asked yourself if you’re a parent. And that’s not limited to parents! Aunts, uncles, grandparents and even teachers may have concerns or questions about the growth of a little one.
Did you know that there’s a simple way to determine whether a child you love is in a healthy weight range, and is growing at a normal rate? It’s called BMI, or body mass index.
In this article, we’ll talk about:
- Normal weight ranges for children
- Whether your children is at risk for disease or health complications
- How to interpret your child’s body mass index
Ready to begin? Let’s explore BMI for children!
What is BMI?
Everyone has a BMI. BMI, or body mass index, is a number that tells you your proportions as they relate to your height and your weight.
In other words, are you too heavy for your height? Are you too thin? Knowing your BMI will give you the answers to those questions.
It’s easy to calculate your body mass index. And the formula is the same for men, women and children. All you’ll do is obtain your measurements – your height in meters and your weight in kilograms.
Once you know your (or your child’s) measurements, you’ll calculate the body mass index. Simple take the weight in kg and divide it by the height in meters. Then, divide the answer by your height in meters again.
That’s it! The answer is your body mass index. Whether you’re 5 or 95, your BMI is calculated the same way.
BMI for Children
Once humans reach the age of around 20, they pretty much stop growing. It’s for that reason that adult BMI is easy to interpret. A body mass index that’s lower than 18.5 is considered underweight, and over 25 is considered overweight. Everything in between is thought to be normal.
Kids are a little different, though. Some kids will shoot up like a weed at, say, age 11, but may not gain weight that matches. Or, a child may gain weight at the age of 14 but not experience a boost in height until 16.
That’s perfectly normal! But it also means that we can’t measure the BMI of a child in the same way that we do the body mass index of an adult. We calculate the BMI in the same way. We just interpret it differently.
Once you calculate your child’s BMI, you’ll compare it to the body mass index of kids similar in age of your child. BMI for kids also takes into account gender, so the body mass index of a boy may be interpreted differently than that of a girl.
Sound confusing? It’s not! Let’s look at how to interpret BMI for children, and how to tell if your child is in a healthy BMI range.
What is a Healthy BMI for Children?
The last time you took your child to the doctor, your pediatrician probably plotted your child’s weight and height on a graph. She then told you whether she had any concerns about your kid’s growth, or whether you son or daughter appeared to be growing “normally.”
You don’t necessarily need to visit the doctor to get an idea of whether your child is growing normally. Instead, simple access the BMI graph for children. See, doctors and scientists from around the world have done research on the growth patterns of kids. Through that research, they’ve discovered that while kids grow at different rates, the patterns are pretty much the same.
What that means is that kids’ body mass index is stated in the form of a percentile. Again, the calculation is the same for figuring out the BMI. But the way you interpret it is by plotting the BMI on a graph.
Once your child’s body mass index is compared to other kids of the same sex and age, you’ll be given a percentile. If your child is below the fifth percentile, that means his size is in the lowest 5% of all kids in his age group. In other words, he’s underweight.
If your child is in the eighty-ninth percentile, that means 89% of boys of his age range are a smaller size than he is. In other words, your child is classified as overweight.
To make things simple, percentiles are expressed in ranges, just like adults’ BMI ranges. A kid with a BMI lower than the 5th percentile is underweight. Between the 85th and 94th, and your child is overweight. And if your kid’s BMI is higher than the 95th percentile, he is considered obese.
Everything else, from 5th to 85th percentile, is considered normal. Your child is at a lower risk for serious health complications than a child who is overweight or obese.
Is There a Special BMI Calculator for Children?
You’ll calculate your kid’s BMI in exactly the same way you will your own. However, there are a few differences in interpretation, and it’s best to use a computer (and a doctor) to help.
First of all, adult BMI doesn’t account for age or sex. In other words, a 25 year old woman who is five feet tall and 160 pounds will have exactly the same BMI as a man who is 57 years old, five feet tall and 160 pounds. There is no difference – they are both classified as obese, with a BMI of 31.2.
Kids’ BMI does take age and sex into account. Boys and girls grow differently, and it’s best to measure that growth against those of their peers.
Secondly, development is different for kids than it is with adults. Your child’s bones, organs and muscles are still growing. Only a pediatrician can tell you definitively if there are health concerns related to the growth of your child.
Using an online calculator to chart your child’s growth is perfectly okay! In fact, doing so will help you keep up with the health of your little one; it may lead to an early diagnosis of any medical concerns.
However, your child’s BMI should never take the place of advice from a pediatrician. Continue to bring your child to the doctor for exams, regardless of whether you know his BMI or not.
Where is the “healthy” limit?
As mentioned, a healthy BMI range for ids is between the fifth and the eighty fifth percentiles. Every weight and height that falls between that range is considered healthy and normal.
If your child falls outside of that range, you’ll need to make an appointment with your doctor. Children who are not within the normal BMI range can suffer a number of health problems, just as adults can.
First of all, an underweight child is usually not receiving adequate nutrition. That doesn’t necessarily mean you’re not properly feeding your child! What it does mean, though, is that your kid is probably lacking in essential vitamins and nutrients essential to growth.
Calcium deficiency is common in kids who are underweight. A calcium deficiency can mean the improper growth of bones, teeth and more. Iron deficiency is also common in kids with a BMI in less than the 5th percentile. Anemia can result, which carries some very unpleasant symptoms.
Underweight kids can suffer in the long term, too. Improper bone health can lead to osteoporosis, which may cause lifelong problems. If your child is underweight, talk to your doctor! Something as simple as a bigger breakfast may be just what your child needs.
Kids who are overweight have a host of health complications. Diabetes, heart disease and even an increased risk of cancer are just a few of the problems that overweight and obese children face. That’s why it’s so important for you to know – and interpret – your child’s BMI.
Does a High BMI Mean My Kid is Unhealthy?
It can’t be stressed enough: a child with a BMI that is outside of the normal range should see a doctor. There are too many risks at stake for you to ignore a high (or a low) BMI in your child. Early detection is the best way to prevent health complications in your child.
However, if your child has a high body mass index that’s outside of the normal range, it doesn’t necessarily mean he or she is unhealthy! Let’s look at an example.
Let’s assume you have twin sons. Both are 16 years old, and both are 5 feet, 7 inches tall. Both also weigh 160 pounds.
Your first son, Larry, loves to play video games. He spends the day in front of his racing game, drinking sugary drinks and eating potato chips and snack foods.
Your other son, Lester, is on the football team. He runs three miles every morning, and while he loves to snack, too, he prefers foods that are lean. He eats carbs for energy and a lot of protein. His goal is to be the quarterback, so he’s building his muscle as best he can.
Both of your sons are, medically, considered overweight. They fall in the 87th percentile, but obviously they have very different lifestyles. In a case like this, Larry’s BMI may be of a bigger concern to you than Lester’s, as Lester is active and eats well.
Put very simply, your child’s BMI isn’t the sole indicator of his health. Lifestyle choices and medical issues come into play when interpreting BMI, and body mass index should never substitute for the advice of a good physician.
BMI for Children: What is Healthy?
As you can see, the BMI of your child is a good indication of how well he or she is growing. Knowing your child’s BMI can not only help you determine the likelihood of disease, but can also help you and your doctor catch concerns before they become problems.
However, it’s absolutely critical that, even if you were to measure your child’s BMI daily, there’s no substitute for a good, healthy lifestyle and the advice of a physician.
You can take steps to improve your child’s general health by tracking his BMI, interpreting the data, then helping him maintain a healthy weight. Remember, though, that every child is different. Kids grow at different rates and at different times, and it’s for that reason that a child’s BMI is not interpreted in the same way as an adult’s.