TUESDAY, Oct. 29, 2024 (HealthDay News) -- Here's another good reason to help your child reach and maintain a healthy weight: A new study warns that kids who are either too skinny or too fat are at risk for impaired lung function.

However, if their weight can be normalized before they reach adulthood, this impairment can be offset, results showed.

“This highlights how important it is to optimize children’s growth both early in life and during their early school years and adolescence,” said principal investigator Dr. Erik Melén, a professor of pediatrics with the Karolinska Institute in Sweden.

About 1 in 10 children have reduced lung function development in childhood, and as a result they can’t achieve maximum lung capacity as adults, researchers explained in background notes.

This increases their risk of serious health problems like heart disease, lung disease and diabetes.

For this study, researchers tracked 3,200 children from birth through age 24. During that period, the kids had their BMI measured between four to 14 times.

“In this study, the largest so far, we’ve been able to follow children from birth all the way to the age of 24, covering the entire period of lung function development,” said lead investigator Gang Wang, a postdoctoral researcher in clinical science and education with the Karolinska Institute.

Kids began to become too skinny, normal weight or too fat by the age of 2, researchers found.

Lung function was measured at ages 8, 16 and 24, researchers said, to give an idea of the children’s airway development.

Unlike children with normal BMI, those with a high or increasing BMI had impaired lung function as adults, primarily the result of restricted airflow in the lungs, results show.

“Interestingly, we found that in the group with an initially high BMI but a normalized BMI before puberty, lung function was not impaired in adulthood,” Melén noted in a Karolinska news release.

Urine samples from the children with high BMI also showed elevated levels of metabolites of the essential amino acid histidine. A similar pattern has been observed in patients with asthma and chronic obstructive pulmonary disease.

“We see here objective biomarkers for the correlation we’ve found, even if we don’t yet know exactly the molecular association between high BMI, histidine and impaired lung development,” Melén said.

But low BMI also was linked to reduced lung function, in that case due to inadequate lung growth, researchers found.

“The focus has been on overweight, but we also need to capture children with a low BMI and introduce nutritional measures,” Wang said.

The new study was published Oct. 28 in the European Respiratory Journal.

More information

The Harvard T.H. Chan School of Public Health has more on obesity and asthma.

SOURCE: Karolinska Institute, news release, Oct. 28, 2024