Infant feeding practices and body mass index up to 7.5 years in the French nationwide ELFE study.

BACKGROUND/OBJECTIVES: The infant diet represents one of the main modifiable determinants of early growth. This study aimed to investigate the associations of infant feeding practices with body mass index (BMI) until 7.5 years. SUBJECTS/METHODS: Analyses were based on data from the French nationwide ELFE birth cohort. Data on breastfeeding (BF) and complementary feeding (CF) were collected monthly from 2 to 10 months. Infant feeding practices were characterized using principal component analyses (PCA) and hierarchical ascendant classification. BMI z-score was computed at 1, 2, 3, 5 and 7.5 years, from data collected in the child's health booklet; 7.5-year overweight was defined according to IOTF references. Associations between infant feeding practices and BMI were investigated by linear regression models adjusted for main confounders. RESULTS: Ever breastfeeding was not associated with BMI up to 7.5 years. Compared to intermediate breastfeeding duration (1 to <3 months), longer breastfeeding duration (≥6 months) was related to lower 1-year BMI, but not at older ages. Compared to the recommended age at CF introduction (4-6 months), early CF (<4 months) was related to higher BMI up to 5 years with a similar trend at 7.5 years, but not to the risk of overweight. The PCA patterns characterized by early baby cereal introduction and late food pieces introduction or by frequent intake of main food groups were related to a lower BMI up to 7.5 years. CONCLUSION: Breastfeeding was related with a lower BMI in infancy but not thereafter, whereas an early CF initiation (<4 months) was associated with a higher BMI in childhood.

Metabolic trade-offs in childhood: Exploring the relationship between language development and body growth.

During human childhood, brain development and body growth compete for limited metabolic resources, resulting in a trade-off where energy allocated to brain development can decrease as body growth accelerates. This preregistered study explores the relationship between language skills, serving as a proxy for brain development, and body mass index at three distinct developmental stages, representing different phases of body growth. Longitudinal data from 2002 children in the EDEN mother-child cohort were analyzed using structural equation modeling. Our findings reveal a compelling pattern of associations: girls with a delayed adiposity rebound, signaling slower growth rate, demonstrated better language proficiency at ages 5-6. Importantly, this correlation appears to be specific to language skills and does not extend to nonverbal cognitive abilities. Exploratory analyses show that early environmental factors contributing to enhanced cognitive development, such as higher parental socio-economic status and increased cognitive stimulation, are positively associated with both language skills and the timing of adiposity rebound in girls. Overall, our findings lend support to the existence of an energy allocation trade-off mechanism that appears to prioritize language function over body growth investment in girls. RESEARCH HIGHLIGHTS: The high energy demand of neurocognitive development leads to a trade-off in human children between brain growth and other biological functions, including body growth. Previous studies indicate that around age 5, when the brain energy consumption peaks, children typically experience a decrease in body mass known as 'adiposity rebound'. A delayed adiposity rebound, indicating slower growth may be associated with enhanced language abilities in children. Our preregistered study confirms this correlation in girls and further associates early cognitive stimulation with improved language skills and delayed adiposity rebound time.

Social patterning of childhood overweight in the French national ELFE cohort.

An inverse social gradient in early childhood overweight has been consistently described in high-income countries; however, less is known about the role of migration status. We studied the social patterning of overweight in preschool children according to the mother's socio-economic and migration background. For 9250 children of the French ELFE birth cohort with body mass index collected at age 3.5 years, we used nested logistic regression to investigate the association of overweight status in children with maternal educational level, occupation, household income and migration status. Overall, 8.3% (95%CI [7.7-9.0]) of children were classified as overweight. The odds of overweight was increased for children from immigrant mothers (OR 2.22 [95% CI 1.75-2.78]) and descendants of immigrant mothers (OR 1.35 [1.04-2.78]) versus non-immigrant mothers. The highest odds of overweight was also observed in children whose mothers had low education, were unemployed or students, or were from households in the lowest income quintile. Our findings confirm that socio-economic disadvantage and migration status are risk factors for childhood overweight. However, the social patterning of overweight did not apply uniformly to all variables. These new and comprehensive insights should inform future public health interventions aimed at tackling social inequalities in childhood overweight.

Parental feeding practices as potential moderating or mediating factors in the associations between children's early and later growth.

BACKGROUND: Given inconsistent results in the literature, our objective was to examine the role of early parental feeding practices in children's growth. METHODS: Analyses were based on 1245 children from the EDEN mother-child cohort. Parental feeding practices were assessed at the 2-year follow-up by using the Comprehensive Feeding Practices Questionnaire. International Obesity Task Force BMI z-scores were derived from weight and height assessed at 2, 4, 6, and 8 years. Associations between parental feeding practices and child BMI z-scores at 4, 6 and 8 years were assessed by multivariable linear regressions, notably adjusted for 2-year BMI z-score. Analyses were stratified by child sex when relevant. Moreover, interaction and mediation analyses were respectively performed to assess whether parental feeding practices could moderate or mediate the associations between early and later growth. RESULTS: For a given BMI z-score at 2 years, parental restriction for weight at 2 years was positively associated with child BMI z-scores from 4 to 8 years (at 8 years: ß [95% CI] = 0.09 [0.01; 0.16]). Among boys only, high use of food as a reward was positively associated with later BMI z-scores (at 8 years: ß [95% CI] = 0.15 [0.03; 0.27]). Parental feeding practices were not moderating factors in the associations between early and later growth. Parental restriction for weight was a mediating factor in the associations between 2-year BMI z-score and BMI z-scores up to 8 years (mediation: 2.69% [0.27%; 5.11%] of the total effect at 8 years). CONCLUSIONS: Restriction for weight reasons, often used by parents in response to the child's high appetite in infancy, appears to lie on the pathway between early and later BMI, but not restriction for health, suggesting that parental way of restricting the child's food intake matters.

Association between perinatal factors, genetic susceptibility to obesity and age at adiposity rebound in children of the EDEN mother-child cohort.

BACKGROUND: Early adiposity rebound (AR) has been associated with increased risk of overweight or obesity in adulthood. However, little is known about early predictors of age at AR. We aimed to study the role of perinatal factors and genetic susceptibility to obesity in the kinetics of AR. METHODS: Body mass index (BMI) curves were modelled by using mixed-effects cubic models, and age at AR was estimated for 1415 children of the EDEN mother-child cohort study. A combined obesity risk-allele score was calculated from genotypes for 27 variants identified by genome-wide association studies of adult BMI. Perinatal factors of interest were maternal age at delivery, parental education, parental BMI, gestational weight gain, maternal smoking during pregnancy, and newborn characteristics (sex, prematurity, and birth weight). We used a hierarchical level approach with multivariable linear regression model to investigate the association between these factors, obesity risk-allele score, and age at AR. RESULTS: A higher genetic susceptibility to obesity score was associated with an earlier age at AR. At the most distal level of the hierarchical model, maternal and paternal educational levels were positively associated with age at AR. Children born to parents with higher BMI were more likely to exhibit earlier age at AR. In addition, higher gestational weight gain was related to earlier age at AR. For children born small for gestational age, the average age at AR was 88 [±39] days lower than for children born appropriate for gestational age and 91 [±56] days lower than for children born large for gestational age. CONCLUSION: The timing of AR seems to be an early childhood manifestation of the genetic susceptibility to adult obesity. We further identified low birth weight and gestational weight gain as novel predictors of early AR, highlighting the role of the intrauterine environment in the kinetics of adiposity.