Prenatal and Early-Life Contributors to Childhood and Adolescent Obesity

Key indicators of childhood and adolescent obesity can be linked to prenatal and early-life environmental influences, according to a study published in JAMA Network Open.¹

The study assessed prenatal exposure to substances and stress, maternal characteristics, prenatal nutritional environments, child characteristics, and demographic covariates as predictors of child and adolescent obesity.

By combining traditional growth mixture models with multiphase latent growth mixture modeling, researchers characterized the trajectories of child BMI, the timing of said transitions, and deviations from typical trajectories. | Image credit: Mediteraneo - stock.adobe.com

“Without intervention, children exhibiting high BMI trajectories during childhood are more likely to develop overweight or obesity as adolescents and adults and are at higher risk for a range of metabolic and cardiovascular diseases throughout their lifetimes,” the authors wrote. “Therefore, it is critical to examine developmental pathways that may lead to unhealthy vs healthy BMIs during childhood and to identify modifiable early-life factors that are associated with BMI trajectories.”

Past research was often unable to measure individual pattern changes and how those patterns may differ from “typical” development, like early or unusual changes. By combining traditional growth mixture models with multiphase latent growth mixture modeling, researchers characterized the trajectories of child BMI, the timing of said transitions, and deviations from typical trajectories.

The study used data from the Environmental Influences on Children's Health Outcomes cohort from January 1997 to June 2024. The cohort was composed of 9483 children (51.9% male and 48.1% female) ages 1 to 9 with 4 or more weight and height assessments, totaling 53,152 BMI observations.

The analysis focused on phases 1 and 2 of childhood development from ages 1 to 9, excluding those younger than 1 year old because of the rapid increase in BMI from birth to 12 months. The cohort was divided into 2 groups: those with typical or atypical BMI patterns. The typical cycle of childhood BMI increases throughout the first year and peaks around the onset of 1 year before reaching its lowest point at about ages 5 to 7, followed by a linear increase in BMI, also known as the adiposity rebound. Previous studies and data suggest an earlier age of adiposity rebound is a biological marker of accelerated growth that is also a potential risk factor for early-onset obesity and cardiometabolic adolescence.

In the typical BMI group (n = 8477 [89.4%]), the BMI pattern showed a linear decrease (b2, −0.23 [95% CI, −0.24 to −0.22]), with the lowest BMI at age 6 years (95% CI, 5.94-6.11), followed by linear increases from 6 to 9 years (slope difference [b4 − b2], 0.81 [95% CI, 0.76-0.86]; mean BMI at 9 years: 17.33). The atypical BMI group (n = 1006 [10.6%]) showed a stable BMI from ages 1 to 3.5 years (b6, 0.06 [95% CI, −0.04 to 0.15]), followed by rapid linear increases from ages 3.5 to 9 years (slope difference [b8 − b6], 1.44 [95% CI, 1.34-1.55]).

At age 9, the atypical group had a BMI of 26.2, exceeding the 99th percentile. Prenatal smoking, high pregnancy BMI, high gestational weight gain, and high birth weight were associated with a higher probability of being in the atypical group. Furthermore, children with a higher birth weight and born preterm were more likely to be in the atypical group.

Additionally, a disturbance to the gut microbiota from mother to fetus intrauterine due to high maternal BMI or high gestational weight gain has been linked to chronic diseases, including child obesity.² A study in the journal Clinical and Experimental Pediatrics associated high pregnancy BMI and gestational weight with a sharp increase in bacterial genera, mainly in the Lachnospiraceae family, resulting in infants more likely to be overweight by 1 year of age, and this increases by 5 if the infant is born by cesarean section.

The clinical utility of the multiphase models in the new study remains unclear, the authors noted, because they are more computationally intensive than standard methods of identifying abnormal growth patterns in children and adolescents.¹ However, the study identified modifiable early-life factors that can impact a child's risk of developing overweight or obesity.

“In this cohort study that used a novel modeling approach, we identified 2 distinct 2-phase BMI patterns that distinguished children on an early path to obesity from those with normative development as early as age 3.5 years,” the authors concluded. “We also identified modifiable early-life factors that may place children at risk for or protect children from childhood obesity.”

References

1. 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

2. Jeong S. Factors influencing development of the infant microbiota: From prenatal period to early infancy. Clinical and Experimental Pediatrics. 2022;65(9):438-447. doi:10.3345/cep.2021.00955