Is Your Skinny Kid Unhealthy?

Medically Reviewed by Hansa D. Bhargava, MD on May 17, 2013
3 min read

Sometimes the scale doesn't matter. Your child might be at a healthy weight -- her body mass index (BMI) is in the normal range and she doesn't look like she has extra pounds.

But looks can be deceiving. If your child doesn't move enough and doesn't eat well, being at a healthy weight doesn't always mean she's actually fit and healthy. The goal for all parents should be to help their kids adopt healthy habits now, so you can help them avoid health problems like diabetes and heart issues related to being unfit.

Experts agree that a person's weight is not always a clear sign of good or bad health or fitness level.

Carl Lavie, MD, medical director of cardiac rehabilitation and prevention at the John Ochsner Heart and Vascular Institute in New Orleans, says the key is being physically fit -- especially getting aerobic exercise. "The people who are unfit, it almost doesn’t matter if they're thin or fat."

Lavie was one of the first researchers to document the "obesity paradox," which found that people who are overweight sometimes live longer and are healthier than people who are thinner.

"If you just look at weight alone, it can be very misleading," Lavie says. "Weight is both fat and muscle. You can have somebody who is normal weight but they don’t have any muscle and they're all fat. On the other hand, you [can] have someone who has pretty high weight and BMI and they're low fat -- like a middle linebacker in the NFL who is huge, but solid muscle."

Weight isn't the perfect predictor of good health. But it's still an important piece of information.

Weight and BMI give you and your child's doctor a basic idea of health, says Jeffrey Schwimmer, MD, director of the Weight and Wellness Center, Rady Children’s Hospital-San Diego. If your child isn't in the "normal" range, he may eventually be more likely to have certain health problems, like high blood pressure, heart disease, and liver disease.

The doctor will also care if someone in your family has a history of health problems like high blood pressure, type-2 diabetes, or fatty liver disease. Family history is a key part of your health information.

As a parent, your job is to help your child build healthy habits, says Stephanie Walsh, MD, medical director for child wellness at Children's Healthcare of Atlanta.

  • Make sure they're active 60 minutes a day. "Are they out there playing and getting sweaty? They need to breathe hard and be a little stinky so you know they're really moving," Walsh says.
  • Fill up half their plates with fruits and vegetables. Give them water, not sugary drinks.
  • Be sure they get plenty of sleep. "If you don’t get enough sleep, everything seems worse," Walsh says. "Lack of sleep puts our bodies at significant stress."
  • Limit screen time, including computers, phones, TV, and video games.

"If we could follow just those basic habits, we would see a significant improvement in the health of our kids, and we wouldn’t need to measure weight," Walsh says. "Your body kind of finds its [ideal] weight if you engage in healthy habits.”

Let your kids join you in setting their own healthy goals -- like exercising for 10 more minutes today or eating broccoli this week. "You have to get the kid's buy-in, because they have to do it," says Walsh. If you have been following healthy habits for a while and still have any concerns, see your child's doctor.

And practice what you preach, because kids learn from your example. Eat healthy meals together. Don't turn on the TV when you send them out to play. Don't obsess about weight -- yours or your child's.

Kids sometimes become thin and unfit because they're afraid of being overweight, so they diet, says Linda Bacon, PhD, a nutrition professor at City College of San Francisco and author of Health at Every Size: The Surprising Truth About Your Weight.

"Kids absorb the outside culture. Everybody absorbs the message that fat is bad and thin is good. They get it from their parent, their schools, the media," Bacon says. "We need to have a counter message in there: Your body is OK because it's yours."