Early-Life Influences Linked to Rapid BMI Rise and Obesity Risk in Children: Study Finds

Analyzing data from 9,483 children enrolled in the NIH-funded Environmental Influences on Child Health Outcomes (ECHO) Program, researchers tracked BMI from ages 1 to 9 and uncovered two primary growth patterns.

The key findings include the following:

• The majority of children (89.4%) exhibited a typical BMI trajectory, with a slight decline in early years followed by a gradual rise beginning around age six.
• Approximately 10.6% of children followed an atypical BMI trajectory, maintaining a stable BMI until about age 3.5, after which it rose sharply, reaching an average of 26.2 by age nine, well above the obesity threshold and exceeding the 99th percentile.
• Maternal smoking during pregnancy was significantly associated with the atypical trajectory (odds ratio [OR] 1.76).
• High birth weight increased the likelihood of following the atypical BMI pattern (OR 1.40).
• Excessive gestational weight gain was another identified risk factor (OR 1.26).
• Preterm birth was linked to a higher risk of atypical BMI development (OR 1.67).
• High maternal BMI before pregnancy showed a strong association with the atypical, obesity-prone trajectory.

“These results suggest that children showing signs of early rapid BMI increase may benefit from closer monitoring and early intervention,” said Dr. Liu. “Preventing obesity may need to begin before birth—through smoking cessation programs for expectant mothers, healthy pregnancy weight management, and improved prenatal care.”

Childhood obesity, often defined as a BMI at or above the 95th percentile for a child's age and sex, has been associated with long-term health risks including diabetes, cardiovascular disease, and metabolic disorders. According to the study, children on the atypical growth path were more likely to retain excess weight into adolescence and adulthood if no interventions were made.

The data used in this cohort study spanned from 1997 to 2024 and were gathered from multiple sources, including caregiver reports, clinical records, and direct measurements. The comprehensive approach allowed researchers to model multiphase BMI changes using latent growth mixture modeling—a statistical method suited for detecting variations in growth trends over time.

The authors emphasized that identifying children at risk early on could lead to more effective, personalized strategies to combat obesity. “Our findings point to critical windows for prevention,” Dr. Liu added.

"As the burden of childhood obesity continues to grow, the study calls for a stronger focus on maternal and infant health as part of broader public health strategies," the authors concluded.

Reference:

Liu C, Chow S, Aris IM, et al. Early-Life Factors and Body Mass Index Trajectories Among Children in the ECHO Cohort. JAMA Netw Open. 2025;8(5):e2511835. doi:10.1001/jamanetworkopen.2025.11835