In adults, BMI values are not linked to age and are the same for both sexes. However, measuring BMI in children and teens is slightly different. Girls and boys develop at different rates and have different amounts of body fat at different ages. For this reason, BMI measurements during childhood and adolescence take age and sex into consideration. Doctors and other health professionals do not categorize children by healthy weight ranges because:
- they change with each month of age
- male and female body types change at different rates
- they change as the child grows taller
- Doctors calculate BMI for children and teens in the same way as they do for adults, by measuring height and weight. Then they locate the BMI number and person’s age on a sex-specific BMI-for-age chart. This will indicate whether the child is within a healthy range.
The following categories explain the meaning of the results:
|Weight status category||Percentile range|
|Underweight||Below the 5th percentile|
|Healthy weight||5th percentile to less than the 85th percentile|
|Overweight||85th to less than the 95th percentile|
|Obesity||Equal to or greater than the 95th percentile|
How doctors use BMI
BMI is not accurate enough to use as a diagnostic tool, but it can screen for potential weight problems in adults and children.
If someone has a high or low BMI, a doctor or other healthcare professional might then consider other factors, such as:
- skinfold thickness measurements, which indicate how much fat is in the body in adults and children
- evaluations of diet and physical activity
- discuss any family history of cardiovascular disease and other health problems
- recommend other appropriate health screenings
The doctor or healthcare professional can then make diet and exercise recommendations based on these results. Excess weight has the following effects on the body:
- It increases how hard the heart has to work.
- It raises blood pressure , blood cholesterol and triglyceride levels.
- It lowers high-density lipoprotein (HDL), or good cholesterol levels.
- It can make diabetes and other health problems more likely.
low self-esteem and psychological stress