Body mass index trajectories from ages 1 to 20: Results from two nationally representative canadian longitudinal cohorts

Abstract

Objective: In this study, unique body mass index (BMI) trajectories from ages 1 to 20 years were identified; each trajectory according to socio demographic and family characteristics was described. Methods: Participants came from two national population surveys (n 5 7,253; n 5 901) and were aged 1-6 years at baseline. Children were surveyed biennially over eight waves up to 14-20 years of age. BMI trajectories by sex and survey cohort were identified by group-based trajectory modeling. After crossvalidating trajectories between survey cohorts, the characteristics of trajectory membership were assessed by multinomial regression. Results: Four BMI trajectories were found: low, decreasing, medium, and high. The decreasing trajectory was characterized by an overweight or obese childhood followed by a normal-weight adolescence. The low, medium, and high trajectories were characterized by growth curves culminating, by age 20, to BMI 22.6, 29.3, and 34.9 kg/m 2 , respectively, for males and 20.6, 24.5, and 32.0 kg/m 2 , respectively, for females. Factors associated with the high trajectory included ethnicity and paternal education (female only), large for gestational age, rural area residence, and maternal smoking. Conclusions: The identification and validation of four major trajectories reflect the heterogeneity in patterns of BMI development from 1 to 20 years.

Body Mass Index Trajectories from Adolescence to Early Young Adulthood: Do Adverse Life Events Play a Role?

“…Only a limited number of studies provided detailed insight into the developmental trajectories of BMI from early adolescence until young adulthood . Three studies using GMM found four distinct BMI trajectories, and one study identified two trajectory classes . In this last study, the identified trajectories were similar to the normal weight and the early onset overweight trajectories identified in the current study .…”

“…In one of the other studies that constrained the variances across classes to be equal, four parallel trajectories were identified . The studies identifying four nonparallel trajectories had solutions resembling the findings of the current study .…”

“…We estimated models with equal variances across classes and unequal variances across classes. Based on previous research, we fitted GMM with one to five classes . At each stage, model fit was evaluated.…”

Association between body mass index percentile trajectories in infancy and adiposity in childhood and early adulthood

“…Group‐based trajectory modeling enables the data themselves to divide a study population into subgroups that present distinct patterns and to fit its own trajectory models for each of those subgroups . Several studies have applied the group‐based trajectory approach to identify distinct weight gain patterns . However, few studies have examined the association between diverse weight gain trajectory patterns in the first 2 years of life and adiposity levels later in life.…”

“…The early programming hypothesis posits that a stimulus or insult experienced during a critical period of development causes permanent alterations in the development and organization of key tissues and organ systems that lead to irreversible changes in the structure and function of the body (10). Several studies have provided supportive data for the link between more rapid weight gain in infancy and an increased risk of developing obesity in later life (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). However, there are knowledge gaps that limit our insight regarding this link.…”