It’s Time to Stop Using BMI

For years, BMI (Body Mass Index) has been one of the most commonly used tools to assess weight and health. You may have even seen it listed on your child’s growth chart at a pediatrician visit– it’s often right on the front page of the AVS (after visit summary). But its reliability has been questioned more and more–rightfully so–especially as we learn just how complex health really is.

BMI was never meant to determine an individual’s health. Yet, it’s often treated as a defining number despite its many flaws, especially for growing children. It doesn’t tell the whole story of a child’s health– it doesn’t account for differences in muscle mass, genetics, or overall well-being, making it a flawed (and often misleading) tool when used on its own. A child who is active, eats well, and sleeps great might still get flagged for a “high BMI”– while another child with different health concerns might fall into the “normal” range. On its own, BMI just doesn’t tell the full story.

The Racial Bias in BMI

BMI was developed based on white European body measurements and never accounted for racial and ethnic diversity. As a result, it misclassifies health risks for many populations. For example, Black children and adults tend to have higher muscle mass and lower body fat at the same BMI compared to white individuals, often leading to unnecessary weight concerns. Meanwhile, Asian populations may develop metabolic conditions at lower BMIs, yet standard cutoffs fail to reflect this risk.

Beyond being an inaccurate tool, BMI reinforces racial health disparities. It disproportionately flags Black and Hispanic children as overweight or obese, sometimes leading to stigma and unnecessary interventions while ignoring systemic factors like access to healthcare and nutrition. Instead of relying on BMI, a more nuanced approach—considering metabolic health, growth patterns, and lifestyle factors—better serves all children.

My personal journey with BMI skepticism

I've never been a fan of BMI—regardless of where a child falls on the curve. In fact, at my first job out of residency, the practice owner specifically asked us not to discuss BMI with families. That request sparked my deep dive into its limitations, particularly for kids. Over time, I realized just how problematic it is—not only because it doesn't reflect a child's true health but also because it can contribute to unnecessary stigma. This is why I’ve always focused on a more holistic approach to assessing health, and I’m glad to see the medical field finally catching up.

A recent shift

Most recently, more and more medical experts are shifting away from BMI as a standalone measure. A recent article outlining new clinical obesity criteria highlights why BMI alone isn’t enough– it lacks the nuance needed to truly assess a person’s health. Instead of relying on weight-based cutoffs, the updated criteria emphasize a more comprehensive approach that considers overall health, metabolic markers, and individual factors beyond just a number on a chart.

If you’ve ever felt concerned or confused when seeing a BMI percentile, you’re not alone. So, what should parents focus on instead? Here’s what to know about BMI’s shortcomings, better ways to assess a child’s health, and how to navigate BMI discussions at the pediatrician’s office.

Why experts are moving away from BMI

BMI was developed as a simple ratio of weight and height, but it was never designed to measure overall health. It doesn’t account for key factors like muscle mass, genetics, or metabolic health– yet it’s still widely used in schools, pediatric offices, and even by insurance companies.

Here’s why it falls short, especially for children:

• It doesn’t distinguish between body composition– a muscular child may have a “high BMI” even if they have low body fat. Meanwhile, a child with less muscle may have a “normal” BMI despite potential health concerns.

• It ignores genetics and growth patterns– children grow at different rates, and BMI doesn’t consider factors like family history, puberty timing, or natural body diversity.

• It can contribute to weight stigma– when BMI is treated as a primary measure of health, it can create unnecessary worry or shame, especially for children who are still developing a relationship with their bodies and body image.

Because of these issues, many health organizations now recommend a more well-rounded approach to assessing health– one that looks beyond BMI percentiles and focuses on the bigger picture.

Experts introduce new criteria for assessing obesity

For years, BMI has been the default tool for assessing weight and health. But experts are finally acknowledging its flaws– and change is (hopefully) on the horizon.

A new article proposes updated clinical obesity criteria to move away from BMI as the primary measure of health. Their goal? To provide a more accurate and medically sound approach to diagnosing and treating obesity.

Here’s a quick overview:

• BMI often underestimates or overestimates body fat because it doesn’t differentiate between muscle, fat, and other factors, BMI can misclassify both children and adults, leading to inaccurate health assessments. The commission recommends that BMI be used only for population-level studies or screenings– not as a standalone diagnostic tool for individuals.

• Obesity is more than just weight. The new criteria define clinical obesity as a chronic illness that affects the function of organs, tissues, and overall health–not just a number on a scale. They also introduce the concept of preclinical obesity, which refers to excess body fat that hasn’t yet caused health complications but increases the risk of developing obesity-related conditions like diabetes and heart disease.

• A better way to assess obesity is needed. Instead of relying solely on BMI, experts now recommend confirming excess adiposity (body fat levels) through direct measurements, waist circumference, or other validated methods.

• Health professionals should look beyond weight labels. The commission emphasizes that obesity-related health risks exist on a continuum and that stigma and oversimplified weight categories are major obstacles to effective care.

This shift is important for parents because it highlights what many of us already know– health is not just about size or weight. A child’s well-being depends on multiple factors, including nutrition, physical activity, sleep, and metabolic health.

The commission also stresses that weight-based stigma and blaming individuals for obesity are harmful. Moving forward, the goal is to ensure that both medical treatment and public health policies are based on evidence-based supportive care–rather than just numbers on a chart. By shifting the conversation away from BMI alone, this new approach encourages a more comprehensive, compassionate way to assess and support children’s health.

Better ways to assess a child’s well-being

If BMI isn’t the best tool, what is? Pediatricians and health experts recommend looking at the full picture of a child’s health instead of relying on a single number. Here are a few key indicators that provide a more full-picture assessment:

• Growth trends over time– a single BMI number doesn’t mean much on its own. Tracking growth patterns over time (not just BMI percentiles) gives a better picture of whether a child is developing as expected.

• Physical activity and strength– is your child active? Strength, endurance, and daily movement are far better indicators of health than weight alone.

• Eating habits and relationship with food– does your child have a balanced approach to eating? Encouraging intuitive eating and positive food experiences helps support both physical and mental well-being.

• Energy levels and overall well-being– how does your child feel day to day? Good energy levels, quality sleep, and the ability to focus are all important signs of health.

• Metabolic markers (if needed)– in some cases, pediatricians may check cholesterol, blood sugar, or nutrient levels–especially if there are other health concerns beyond weight.

By focusing on these areas, we get a more nuanced, supportive approach to health– one that meets each child where they are rather than reducing them to a number on a chart.

Navigating BMI conversations at the Pediatrician’s office

Many parents have experienced that awkward moment when a pediatrician points out a child’s BMI percentile– sometimes leading to unnecessary concern or confusion. If this happens, you can advocate for a more balanced, health-focused discussion by shifting the conversation beyond just numbers.

Ask about the bigger picture– if BMI comes up, dig deeper by asking:

Reframe the focus from weight to habits– if your child’s BMI is labeled as high or low, shift the discussion to daily habits rather than numbers. For example:

Protect your child’s body image– if BMI is discussed in front of your child, it’s okay to redirect or ask for a private conversation. For example:

At the end of the day, a single number doesn’t define your child’s health. Focusing on growth patterns, habits, and overall well-being leads to a more supportive and accurate approach.

More on this topic

If you’ve ever wondered how percentiles, BMI, and body image all connect– or how to navigate these conversations as a parent– this podcast episode is for you.

In this episode, I chat with Jessica Gust, a pediatric dietitian, about:

• When percentiles are actually helpful

• Why BMI isn’t the best tool for assessing health

• How to focus on eating habits instead of weight

• What parents can do to support a positive body image in kids

Final thoughts

BMI was never meant to be a perfect tool, and more experts are recognizing its limitations– especially for children. Health is so much more than a number on a chart.

When we look beyond BMI and focus on growth, movement, and daily habits, we can help our children see their bodies as strong and capable– just as they are. We teach them that health isn’t defined by a label but by how they feel, how they move, and how they care for themselves. And most importantly? This is how we help them build self-trust, confidence, and a healthy relationship with their bodies.

On The Podcast

Talking to kids about the news requires honesty while maintaining a sense of security. Open conversations help build trust, allowing kids to ask questions and process difficult topics in a supportive environment. This week, I welcome Rebecca Jarvis, contributing anchor at Good Morning America, to discuss how parents can provide age-appropriate explanations for real-world concerns while ensuring their kids feel safe.

She joins me to discuss:

• The importance of honesty, security, and age-appropriate conversations about the news.

• How she navigates being present with her kids while managing a demanding career.

• How small positive actions can help us find purpose in uncertain times.

On YouTube

As a pediatrician and a mom, I walk you through my step-by-step approach to managing fevers when my kids aren’t feeling well. I’ll answer common questions I receive and share my best tips for bringing a fever down. This video covers:

• What temperature is a fever?

• When should you check for a fever?

• How to take your kids’s temperature? What is the best medication for a fever?

• Should I alternate meds?

• Non-medication comfort measures

• When should I take my child to the doctor with a fever?

Ask Dr. Mona

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Dr. Mona will answer these questions in a future Sunday Morning Q&A email. Chances are if you have a parenting concern or question, another parent can relate. So let's figure this out together!