Is the BMI the best tool for assessing kids’ weight?

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Imagine getting a letter from your child’s school telling you that his or her weight is a problem. It’s happening in some places in the U.S. as a result of screening programs to determine obesity rates. News reports and late-night comedy shows have dubbed them “fat letters”. The information sent to parents includes the child’s Body Mass Index (BMI) percentile and weight category.

The BMI, a measure calculated using a person’s weight and height, is used as an indicator of how much fat a person may be carrying, relative to their height. But it’s only one indicator and it’s not without controversy, especially when it’s used for children. Kids with a muscular, athletic build, when screened using the BMI, can mistakenly be classified as being overweight or obese. As a result, experts have suggested using the BMI as a screening tool, but not a diagnostic tool.

Controversy aside, it can point to potential weight issues and possibly an opportunity to assess healthy eating attitudes and practices in your home.

The focus nowadays on halting the epidemic of childhood obesity can definitely take a toll on a child’s self-esteem. Put that together with society’s obsession with thinness – for example, which celebrity has shed her baby weight the fastest – and kids are getting the message that you have to be a perfect weight to be happy.

Healthy weights are indeed key to decreasing the risk of a range of lifestyle related diseases later in life, but achieving that goal in a positive way may require some strategies.

First, don’t take part in what I call trash talk about weight – either about yourself or others. Children notice this, even if they’re not included in the conversation. The potential harm, for instance, when a mother refuses to wear a bathing suit because of her body, can make quite an impression on kids. Or when parents talk about each other or friends and their weight gain in front of kids, it can have a major impact.

Second, forget the gentle reminders to your children to watch their weight. Suggesting they forego second servings at dinner or avoid certain foods because they’re fattening sends the wrong message.

Research published in the journal Pediatrics demonstrates just how destructive seemingly harmless remarks can be to children’s self-esteem and body image as they grow. The study looked at female college students who were part of an eating disorder prevention program and found that more than 80 percent received negative comments about their weight from their parents or siblings when they were young.

A positive food environment is also critical to managing weight issues. Having the whole family on the same page with menu planning makes for an easier task. In many families, there can be one underweight child while another is overweight. The same food rules should apply to all – including the parents.

Nutrition tips for kids

  1. Skip the kids’ meals at restaurants. Most are loaded with fat and calories. Instead, have them share healthier options or order half portions.
  2. Rather than nagging that junk food is fattening, emphasize that it won’t provide the nutrients to grow tall (most kids want to be taller) or lead to peak performance for activities such as hockey, dance or even tag in the same way that healthy food will.
  3. Instead of rewarding achievements with food, such as candy, use other items that your kids value, such as stickers or other small trinkets.
  4. Avoid the “See Food” diet: Keep the junk food out of sight and in hard-to-reach places. If it’s out of sight, it’s out of mind.
  5. Allow treats, but put a limit on them.

Rosie Schwartz is a Toronto-based consulting dietitian in private practice and author of The Enlightened Eater’s Whole Foods Guide (Viking Canada). Visit for more.

Originally published in ParentsCanada magazine, December 2013.


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