BMI and Children: Should we do something?

by Noelle Castoro, LCSW

Recently on a well-child visit for my son, the pediatrician sat down to talk about his height and growth curve. These are pretty meaningless numbers to a child, and he listened half-heartedly as you may expect from a preteen. Then she began to talk about body mass index. This is where I interrupted her and said, “We don’t talk about BMI in our family.” She looked at me with her mouth slack. “BMI is not based on science and is no indication of health.”

Clearly, she was displeased, but agreed, “Yes, BMI does not tell us anything about his health.”

“Then let’s not talk about it,” I responded.

“It’s just a way to compare a kids’ size to other kids,” she replied.

“Why would we want to do that?” I asked.

Yes. This really happened. It's possible that I slipped into the conversation that I work with individuals with food and eating-related issues for street cred...She dropped the subject and continued with the rest of the well-check, somewhat awkwardly.


What we need to know about BMI?

BMI is scientifically based insofar as it is a mathematical equation. It is the ratio between height and weight. It does not take into consideration bone density, musculature, stomach contents, fluid retention, or health in any way (McMaster University, 2019). It was designed to categorize fatness, and in assigning a ratio of fatness, we can then determine what our insurance rates will be (Pelvin, 2015, Trefelthen, 2013). To that end, the BMI chart that determines what range a person's weight falls into has also changed over time. Overnight, people who were in an "average" range became "overweight" because it was cost-effective for insurance companies and the diet industrial complex to make that adjustment. Weight is big business. But their actual health did not change — just the label on their size. What BMI also doesn’t tell us is how bright, witty, or interesting you are.

Scientists argue that “body mass index is the standard metric for determining who is normal-weight, overweight and obese, but BMI is not an accurate measure of fat, and doesn't explain the causes of poor health” (Science Journal, August 2013,

Emphasizing BMI with children can create feelings of shame and inadequacy. And what children experience inside often shows up in their bodies.


So what do we do if we are concerned
about our child’s size?

After all, we have all heard of the alarming “obesity epidemic” happening in Western culture. What parent wouldn’t want push dieting as a way to help their child avoid all the pitfalls and social problems that come with larger sized bodies? When does weight actually impact health? How should parents approach this with their children?


1. Never endorse dieting

Calorie reduction is not proven as an effective long term tool for lowering body size. In fact, diets fail over 95% of the time. And for those in that elusive 5% for whom they successfully kept the weight off, there is evidence that they live with restrictive or disordered eating symptoms that can negatively impact their physical and psychological health. If a plane had a 95% chance of falling out of the sky, would you fly on it? Why is this an acceptable prescription for altering size? Children who are put on a diet are 13 times more likely to develop an eating disorder, and anorexia has the highest mortality rate of all mental illnesses. For females 15-24 years old, the mortality rate for anorexia is 12 times higher than any other cause of death (NEDA, 2019).


2. Ditch the clean plate club

Allow your child to listen to their hunger. This can be challenging with imposed meal times, especially for school-aged children. But think back to when they were toddlers. If they were hungry, they would eat, but when they were satisfied, they could leave half a cupcake on their plate and go off to play. Young children are tuned into their inner food wisdom. Continue to foster that healthy relationship with food and their body’s needs by believing them when they say they are hungry and when they have had enough. Praise for finishing food or for not eating much is damaging to this delicate communication between their brain and their body. Help them nurture this, too, by listening to your own hunger and refusing to diet.


3. Remember that bodies come in all shapes and sizes

Just as we have different skin tones, hair color, and height, we also come in different sizes. Rather than tell your child that they have to change their given body size, help them learn to appreciate the differences in people. Diversity is a beautiful part of being human. Let’s teach our children to embrace the differences in people rather than judge themselves or others for not conforming to a single body type.

One child can eat X amount of food and be very small. Another child can eat the exact same amount and be larger. That doesn't mean the second child is entitled to less food; it means only that their body size is naturally larger. Our job is to support our children in loving and accepting themselves just as we love and accept them.

We often hear people ask, "but what about their health?" Of course, we want our children to live long, healthy lives and we have an obligation to help them do that. Lower weights do not guarantee a healthy body and in fact research shows us that weight cycling, the act of gaining and losing weight over and over again, has a much more detrimental effect on long term health outcomes than if a person remains a higher weight consistently (Tae Jung Oh, et al, 2018). If we want to create healthy habits for our children, offering a wide variety of foods and allowing them to eat when they are hungry and to stop eating when they are full will go a lot farther toward that goal than enforcing weight suppressing and calorie restricting diets.

Poor body image is also linked to negative health outcomes. What is termed “internalized fat stigma” or, the belief that one’s value and self-worth hinges on body size, has a greater negative impact on mental and physical wellness than actually having a larger body (Tomiyama, et al, 2018).

Body acceptance is difficult to do in a culture that seems to place value on a lack of body diversity. Navigating the messages of diet culture, especially in the guise of “wellness” is tricky. But making peace with food and our bodies is essential for our mental health and our physical health, as well as the health of our children, because they are listening to us. If we want our children to have an accepting and peaceful relationship with their bodies and make choices about food from an intuitive, wise place, then our first step is to model that for them.

If you are ready to make peace with food or to find body acceptance, reach out for help. It often takes the safe, guiding hand of someone who has made the journey to walk it with you.

If you wish to set up an appointment with Noelle Castoro or one of our clinicians please call 703-636-2888, ext. 4 or send an appointment request via our contact form