Most obese adolescents first became obese between the ages of 2 and 6 years, based on data from approximately 50,000 children in Germany.
Identifying periods of weight gain in childhood can help develop intervention and prevention strategies to reduce the risk of obesity in adolescence, wrote, of the University of Leipzig, Germany, and her colleagues in the .
To assess the timing of weight gain in early childhood, the researchers reviewed data from a German patient registry designed to monitor growth data. The study population included 51,505 children who had at least one visit to a pediatrician between birth and age 14 years and a second visit between age 15 and 19 years.
Overall, the probability of being overweight or obese in adolescence was 29% among children who gained more weight in the preschool years, between the ages of 2 and 6 years (defined as a change in body mass index [BMI] of 0.2 or more to less than 2.0), compared with 20% among children whose preschool weight remained stable (defined as a change in BMI of more than −0.2 to less than 0.2) – a relative risk of 1.43.
“A total of 83% of the children with obesity at the age of 4 were overweight or obese in adolescence, and only 17% returned to a normal weight,” they wrote. In addition, 44% of children who were born large for gestational age were overweight or obese in adolescence.
“A practical clinical implication of our study results would be surveillance for BMI acceleration, which should be recognized before 6 years of age, even in the absence of obesity,” the researchers wrote.
The study findings were limited by several factors including the variation in the number of visits, the lack of data on many children beyond the age of 14 years, and the lack of data on parental weight and perinatal risk factors associated with obesity, the researchers noted. However, the results were strengthened by the large, population-based design, and support the study hypothesis that obesity develops in early childhood and, once present, persists into adolescence.
“The specific dynamics and patterns of BMI in this early childhood period, rather than the absolute BMI, appear to be important factors in identifying children at risk for obesity later in life,” the researchers wrote. “It is therefore important for health care professionals, educational staff, and parents to become more sensitive to this critical time period.”
The study was supported by the German Research Council for the Clinical Research Center; the Federal Ministry of Education and Research; and the University of Leipzig, which was supported by the European Union, the European Regional Development Fund, and the Free State of Saxony within the framework of the excellence initiative. The CrescNet registry infrastructure was supported by grants from Hexal, Novo Nordisk, Merck Serono, Lilly Deutschland, Pfizer, and Ipsen Pharma. Dr. Geserick had no financial conflicts to report.
SOURCE: Geserick M et al. N Engl J Med. 2018 Oct 3. .