Each one unit increase in BMI (body mass index) at age six more than doubles the likelihood of being overweight or obese at age 18. This is the conclusion reached by researchers from the Rotterdam Medical Center. The results of the study are being presented at the European Congress on Obesity (ECO 2025).

A total of 3,528 Dutch children participated in the study. Their body mass index was monitored (BMI) at the ages of two, six, 10, 14 and 18 years. Among the young participants, 32.3% were overweight or obese at age two, 22.3% at age six, 24.7% at age 10 and 20.6% at age 14.

Being overweight at age six was found to correlate closely with obesity in youth. However, provided the child returns to a normal body weight when they reach the age of six, this risk is offset.

“The incidence of obesity in adolescents has increased significantly over the past 15 years. This is due to heavy consumption of highly processed factory foods, sedentary lifestyles, lack of sleep and mental health problems,” said lead researcher Dr. Dinesh Giri, a consultant pediatric endocrinologist at Bristol Royal Children's Hospital.