BMI in Kids and Adolescents
Research has shown that genetics can contribute to obesity, with BMI being up to 40% heritable. However, environmental and behavioral factors also play a significant role in weight gain. The genetic component of obesity in children is less than 5%. Therefore, while genetics can be a factor, it is not the sole cause of the alarming rise in childhood obesity.
While BMI is commonly used to evaluate weight status in adults, Kids BMI is also a useful tool for assessing the health of children and adolescents.
What are the BMI Criteria in Kids and Adolescents?
BMI is calculated the same way for kids and adolescents as it is for adults, using the formula weight in kilograms divided by height in meters squared (kg/m2). However, since children and teens are still growing and developing, their BMI results must be interpreted differently than those of adults.
BMI-for-age growth charts have been developed by the Centers for Disease Control and Prevention (CDC) to take into account age- and sex-specific differences in body fat in kids and adolescents. The charts show BMI as a percentile, indicating the child’s BMI compared to other children of the same age and sex.
How to Interpret BMI in Kids and Adolescents?
According to the CDC (Centers for Disease Control and Prevention), BMI percentile ranges for children and adolescents are categorized as underweight, healthy weight, overweight, or obese. The following percentile ranges are used:
Underweight: Less than the 5th percentile
Healthy Weight: 5th percentile to less than the 85th percentile
Overweight: 85th percentile to less than the 95th percentile
Obese: Equal to or greater than the 95th percentile
It’s important to note that children and adolescents are still growing and developing, so their BMI percentile may change over time. A single high or low percentile does not necessarily indicate a problem, but rather a trend over time should be monitored and discussed with a healthcare provider.
Importance of Achieving Healthy BMI in Kids and Teenagers
Maintaining a healthy BMI is important for kids and adolescents because it can impact their overall health and well-being. Children and adolescents who have a BMI in the overweight or obese range are at increased risk for developing a variety of health problems, including type 2 diabetes, high blood pressure, sleep apnea, and joint problems. They may also be at risk for low self-esteem and bullying.
On the other hand, children and adolescents who are underweight may be at risk for nutrient deficiencies, delayed growth and development, and weakened immune systems. It’s important to know that underweight can also be a sign of an underlying medical condition.
How Can Parents Help Kids and Adolescents Maintain a Healthy BMI?
There are many ways that parents and caregivers can help kids and adolescents maintain a healthy BMI. Here are some recommendations:
Encourage Healthy Eating Habits: Provide a variety of nutrient-dense foods, including fruits, vegetables, whole grains, lean protein, and low-fat dairy. Limit processed and high-calorie foods and sugary drinks.
Make Physical Activity Fun: Encourage children and adolescents to be physically active for at least one hour a day. This can include activities such as playing outside, dancing, swimming, and sports.
Limit Screen Time: Limit the amount of time children and adolescents spend on screens, including TV, video games, and smartphones. Children should not spend more than two hours a day watching screens.
Be a Positive Role Model: Children and adolescents are more likely to adopt healthy habits if they see their parents and caregivers doing the same.
Talk to a Healthcare Provider: If you are concerned about your child’s BMI, talk to a healthcare provider. They can provide guidance and support to help your child maintain a healthy weight.
Consequences of Obesity for Kids and Teenagers
According to Childhood Obesity Foundation, the obesity epidemic may cause children to live shorter lives than their parents for the first time in history. For example;
• Childhood obesity can have serious health consequences both in the short-term and long-term.
• Obese children are at risk of developing conditions like type 2 diabetes, high blood pressure, liver disease, asthma, and sleep disorders.
• They may also experience psychological issues like poor self-esteem, depression, and social isolation.
• Unfortunately, most overweight children do not outgrow their weight problems and continue to gain weight as they age, which can lead to serious health conditions in adulthood such as heart disease, cancer, and dementia.
It’s crucial for families to take preventive measures against childhood obesity and seek treatment if necessary.
Why Is BMI Different for Adults and Kids?
BMI is interpreted differently for children and adults due to differences in body composition as they grow and develop. In children, BMI is compared to age and sex-specific growth charts to determine whether a child is underweight, healthy weight, overweight, or obese. In adults, BMI is compared to standard weight categories to determine whether a person is underweight, normal weight, overweight, or obese. This difference is due to the fact that children’s bodies change significantly as they grow and develop, and their BMI reflects their changing body composition over time.
