Relationship between prenatal growth, postnatal growth and childhood obesity: a review

Longitudinal study of birthweight, blood pressure, and markers of arterial stiffness in children age six among the TIDES cohort

OBJECTIVE

Although some studies have observed an association between birthweight and cardiovascular disease in adulthood, fewer have investigated whether birthweight is linked to cardiovascular health in early childhood. This study assesses the association between birthweight and cardiovascular outcomes in children 6 years of age.

STUDY DESIGN

Birthweight, blood pressure (BP), and markers of arterial stiffness in children, including brachial artery distensibility and carotid-femoral pulse wave velocity (cfPWV), were obtained from 324 participants in The Infant Development and the Environment Study, a prospective multisite pregnancy cohort. Birthweight was converted into sex-specific birthweight-for-gestational-age (bw/ga) z -scores based on the INTERGROWTH-21st standard. Following 2017 American Academy of Pediatrics guidelines, SBP and DBP were transformed into sex, age, and height-specific z -scores. Associations between birthweight and cardiovascular outcomes were assessed using nested multivariable linear regression models among the overall and sex-stratified samples.

RESULTS

Among the overall sample, bw/ga z -score was positively associated with cfPWV [b = 0.11 m/s, 95% confidence interval (CI): 0.01 m/s, 0.21 m/s] in crude and adjusted models. No associations between birthweight and cardiovascular outcomes were detected among the sex-stratified analyses.

CONCLUSION

Overall, birthweight was not related to cardiovascular outcomes in children 6 years old. However, infants born with a higher birthweight may be at risk for higher cfPWV in childhood. Early intervention in pregnant people at risk of delivering high birthweight infants may be warranted if results are replicated.

The joint effects of prenatal exposure to PM2.5 constituents and reduced fetal growth on children's accelerated growth in the first 3 years: a birth cohort study

BACKGROUND

Prenatal fine particulate matter (PM2.5) constituents exposure and reduced fetal growth may be risk factors for accelerated growth in early childhood, an important indicator for lifelong health.

OBJECTIVE

The study investigated whether the joint effects are present between PM2.5 constituents and reduced fetal growth.

METHODS

The study was embedded in a birth cohort in China, including 5424 mother-child pairs. Prenatal PM2.5 and its constituents' [organic carbon (OC), elementary carbon (EC), ammonium (NH4+), nitrate (NO3-), and sulfate (SO42-)] concentrations were estimated based on maternal residential addresses. Fetal growth was evaluated by fetal growth trajectory in utero and preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA). Children's accelerated growth was defined as body mass index (BMI) Z-score change of >0.67 between birth and 3 years. Generalized logistic regression was used to analyze the effects of prenatal PM2.5 constituents exposure and fetal growth on children's accelerated growth. Joint effect was tested on multiplicative scale and additive scale with the relative excess risk due to interaction (RERI).

RESULTS

Children with lower fetal growth trajectory, PTB, LBW, and SGA had increased odds of children's accelerated growth, with odds ratios (ORs) ranging from 1.704 to 11.605. Compared with lower exposure (≤median), higher exposure (>median) of PM2.5, OC, and SO42- were significantly associated with increased odds of children's accelerated growth, varying in ORs from 1.163 to 1.478. Prenatal exposure to OC had joint effects with lower fetal growth on children's accelerated growth. We observed that the interaction was statistically significant on an additive scale in OC and lower fetal growth trajectory (RERI: 0.497, 95% CI: 0.033,0.962).

IMPACT

Fine particulate matter (PM2.5) is a huge threat to human health worldwide, causing 6.7 million death globally in 2019. According to the theory of DOHaD, prenatal PM2.5 exposure could influence early childhood growth, which is important for lifelong health. We found that prenatal exposure to PM2.5, OC, and SO42- was associated with higher risk of accelerated childhood growth in the first 3 years. More importantly, reduced fetal growth moderated these associations. Our findings highlight the need for policies and interventions on PM2.5 constituents to improve lifelong health, especially for those vulnerable populations with reduced fetal growth.

Blood pressure and lipid profiles in children born after ART with frozen embryo transfer

STUDY QUESTION

Are blood pressure (BP) and lipid profiles different between children conceived after ART with frozen embryo transfer (FET), fresh embryo transfer (fresh-ET), and natural conception (NC)?

SUMMARY ANSWER

Girls conceived after FET had significantly higher systolic BP and heart rate compared with girls born after fresh-ET; boys conceived after FET had a slightly more favourable lipid profile compared with boys born after fresh-ET and NC.

WHAT IS KNOWN ALREADY

Children conceived after ART with FET are more often born large for gestational age (LGA). LGA in general increases the risk of obesity, diabetes, and cardiovascular disease later in life. Studies on mice and humans on the whole ART population have raised concerns about premature vascular ageing and higher BP. The cardiovascular health of children born after FET is scarcely explored and the results are diverging.

STUDY DESIGN SIZE DURATION

This study was part of the cohort study 'Health in Childhood following Assisted Reproductive Technology' (HiCART), which included 606 singletons (292 boys) born between December 2009 and December 2013: 200 children were conceived after FET; 203 children were conceived after fresh-ET; and 203 children were conceived naturally and matched for birth year and sex. The study period lasted from January 2019 to September 2021.

PARTICIPANTS/MATERIALS SETTING METHODS

The included children were 7-10 years of age at examination and underwent a clinical examination with anthropometric measurements, pubertal staging, and BP measurement. Additionally, a fasting blood sample was collected and analysed for cholesterol, low-density lipoproteins (LDL), high-density lipoproteins (HDL), and triglycerides. Systolic and diastolic BP were converted to standard deviation scores (SDS) using an appropriate reference and accounting for height (SDS) of the child. The three study groups were compared pairwise using a univariate linear regression model. Mean differences were adjusted for confounders using multiple linear regression analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

Girls and boys conceived after FET had significantly higher birthweight (SDS) compared with naturally conceived peers (mean difference: girls: 0.35, 95% CI (0.06-0.64), boys: 0.35, 95% CI (0.03-0.68)). Girls conceived after FET had significantly higher systolic BP (SDS) and heart rate compared with girls conceived after fresh-ET (adjusted mean difference: systolic BP (SDS): 0.25 SDS, 95% CI (0.03-0.47), heart rate: 4.53, 95% CI (0.94-8.13)). Regarding lipid profile, no significant differences were found between the three groups of girls. For the boys, no significant differences were found for BP and heart rate. Lipid profiles were more favourable in boys born after FET compared with both boys conceived after fresh-ET and NC. All outcomes were adjusted for parity, maternal BMI at early pregnancy, smoking during pregnancy, educational level, birthweight, breastfeeding, child age at examination, and onset of puberty.

LIMITATIONS REASONS FOR CAUTION

The participation rate varied from 18 to 42% in the three groups, and therefore selection bias cannot be excluded. However, extensive non-participant analyses were performed that showed almost no differences in background characteristics between participants and non-participants in the three groups, making selection bias less likely.

WIDER IMPLICATIONS OF THE FINDINGS

The higher birthweight in children conceived after FET was associated with increased systolic BP (SDS) and heart rate in girls conceived after FET compared with fresh-ET. This may be an early indicator of compromised long-term cardiovascular health in this group. The study was not powered to investigate these outcomes and further studies are therefore warranted to confirm the findings.

STUDY FUNDING/COMPETING INTERESTS

The study was funded by the Novo Nordisk Foundation (grant number: NNF18OC0034092, NFF19OC0054340) and Rigshospitalets Forskningsfond. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT03719703.

Early Home Visits and Health Outcomes in Low-Income Mothers and Offspring: 18-Year Follow-Up of a Randomized Clinical Trial

Importance

Individuals with low income may have heightened rates of obesity and hypertension.

Objective

To determine whether prenatal and infancy home visitation by nurses reduces maternal and offspring obesity and hypertension.

Design, Setting, and Participants

This randomized clinical trial of prenatal and infancy nurse home visitation in a public health care system in Memphis, Tennessee, enrolled 742 women with no previous live births and at least 2 sociodemographic risk factors (unmarried, <12 years of education, unemployed) from June 1, 1990, through August 31, 1991. At registration during pregnancy, 727 mothers (98%) were unmarried, and 631 (85%) lived below the federal poverty level. At offspring ages 12 and 18 years, maternal and offspring obesity and hypertension were assessed by staff masked to treatment. The data analysis was performed from July 1, 2021, to October 31, 2023.

Interventions

Women assigned to the control group received free transportation for prenatal care and child developmental screening and referral at child ages 6, 12, and 24 months. Women assigned to nurse visitation received transportation and screening plus prenatal and infant and toddler nurse home visits.

Main Outcomes and Measures

Obesity and hypertension among mothers and their offspring at child ages 12 and 18 years, although not hypothesized in the original trial design, were analyzed using post-double selection lasso method.

Results

Of the 742 participants randomized (mean [SD] age, 18.1 [3.2] years), interviews were completed with 594 mothers and 578 offspring at child age 12 years and 618 mothers and 629 offspring at child age 18 years. Obesity was assessed for 576 offspring at age 12 years and 605 at age 18 years and for 563 and 598 mothers at child ages 12 and 18 years, respectively. Blood pressure was assessed for 568 offspring aged 12 years and 596 aged 18 years and 507 and 592 mothers at child ages 12 and 18 years, respectively. There were no overall treatment-control differences in offspring obesity or hypertension at ages 12 and 18 years combined, although nurse-visited female offspring, compared with controls, had a lower prevalence of obesity (adjusted relative risk [ARR], 0.449; 95% CI, 0.234-0.858; P = .003) and severe obesity (ARR, 0.185; 95% CI, 0.046-0.748; P < .001). There were reductions at ages 12 and 18 years combined for stage 1 and stage 2 hypertension for nurse-visited vs control group mothers, with differences limited to mothers of females (stage 1: ARR, 0.613 [95% CI, 0.440-0.855; P = .001]; stage 2: ARR, 0.217 [95% CI, 0.081-0.582; P < .001]). For both obesity and hypertension outcomes, there was no intervention effect among male offspring or the mothers of males. Self-reported maternal health aligned with program effects on hypertension.

Conclusions and Relevance

In this clinical trial follow-up at offspring ages 12 and 18, nurse-visited female offspring had lower rates of obesity and mothers of females had lower rates of hypertension than control-group counterparts. These findings suggest that risks for chronic disease among mothers of females and their female offspring who live in extreme poverty may be prevented with prenatal and infant and toddler home visitations by nurses.

Trial Registration

ClinicalTrials.gov Identifier: NCT00708695.

Breastfeeding duration and associations with prevention of accelerated growth among infants from low-income, racially and ethnically diverse backgrounds

OBJECTIVE

To describe breastfeeding rates from early to late infancy and to examine associations between breastfeeding duration and infant growth, including rapid weight gain (RWG, > 0·67 SD increase in weight-for-age Z-score), among infants from low-income, racially and ethnically diverse backgrounds.

DESIGN

A short, prospective cohort study was conducted assessing breastfeeding status at infant ages 2, 4, 6, 9 and 12 months. Infant length and weight measurements were retrieved from electronic health records to calculate weight-for-length Z-scores and the rate of weight gain.

SETTING

Pediatric clinic in the Southeastern USA.

PARTICIPANTS

Mother-infant dyads (n = 256).

RESULTS

Most participants were African American (48 %) or Latina (34 %). Eighty-one per cent were participating in the Special Supplemental Nutrition Program for Women, Infants and Children. Infants were breastfed for a median duration of 4·75 months, with partial more common than exclusive breastfeeding. At 12 months, 28 % of the participants were breastfeeding. Infants breastfed beyond 6 months had significantly lower growth trajectories than infants breastfed for 0-2 months (β = 0·045, se = 0·013, P = 0·001) or 3-6 months (β = 0·054, se = 0·016, P = 0·001). Thirty-six per cent of the infants experienced RWG. RWG was more common among infants who were breastfed for 2 months or less than 6+ month breastfed group (relative risk = 1·68, CI95 (1·03, 2·74), P = 0·03).

CONCLUSIONS

Breastfeeding beyond 6 months is associated with the prevention of accelerated growth among infants from low-income, racially and ethnically diverse backgrounds, suggesting progress toward health equity.

"My wellbeing-their wellbeing "- An eHealth intervention for managing obesity in early care and education: Protocol for the Go NAPSACC Cares cluster randomized control trial

BACKGROUND

To fully leverage the potential of the early care and education (ECE) setting for childhood obesity prevention, initiatives must not intervene solely at the organizational level, but rather they should also address the health needs of the ECE workers. Workers suffer disproportionately high rates of obesity, and have reported low confidence in modeling and promoting healthy eating and activity behaviors. However, information regarding the effectiveness of improving ECE workers' health behaviors or whether such improvements elicit meaningful change in the ECE environment and/or the children in their care is limited.

METHOD

The proposed study will integrate a staff wellness intervention into a nationally recognized, ECE obesity prevention initiative (Go NAPSACC). Go NAPSACC+ Staff Wellness program will be assessed using a clustered randomized controlled trial including 84 ECE centers, 168 workers, and 672 2-5-year-old children. Centers will be randomly assigned to 1) standard "Go NAPSACC" or 2) Go NAPSACC+ Staff Wellness. Outcome measures will assess impact on dietary intake and PA behaviors of 2-5-year-old children at 6 months (primary aim) and 12 months. Secondarily, we will compare the impact of the intervention on centers' implementation of healthy weight practices and the effect on ECE workers' diet quality and PA at 6- and 12 months.

DISCUSSION

This trial expects to increase our understanding of how ECE worker's personal health behaviors impact the health behaviors of the children in their care and the ECE environment.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05656807, registered on 19 December 2022. Protocol version 1.0, 22 March 2023.

Neighborhood Food Environment and Birth Weight Outcomes in New York City

Importance

Infants born with unhealthy birth weight are at greater risk for long-term health complications, but little is known about how neighborhood characteristics (eg, walkability, food environment) may affect birth weight outcomes.

Objective

To assess whether neighborhood-level characteristics (poverty rate, food environment, and walkability) are associated with risk of unhealthy birth weight outcomes and to evaluate whether gestational weight gain mediated these associations.

Design, Setting, and Participants

The population-based cross-sectional study included births in the 2015 vital statistics records from the New York City Department of Health and Mental Hygiene. Only singleton births and observations with complete birth weight and covariate data were included. Analyses were performed from November 2021 to March 2022.

Exposures

Residential neighborhood-level characteristics, including poverty, food environment (healthy and unhealthy food retail establishments), and walkability (measured by both walkable destinations and a neighborhood walkability index combining walkability measures like street intersection and transit stop density). Neighborhood-level variables categorized into quartiles.

Main Outcomes and Measures

The main outcomes were birth certificate birth weight measures including small for gestational age (SGA), large for gestational age (LGA), and sex-specific birth weight for gestational age z-score. Generalized linear mixed-effects models and hierarchical linear models estimated risk ratios for associations between density of neighborhood-level characteristics within a 1-km buffer of residential census block centroid and birth weight outcomes.

Results

The study included 106 194 births in New York City. The mean (SD) age of pregnant individuals in the sample was 29.9 (6.1) years. Prevalence of SGA and LGA were 12.9% and 8.4%, respectively. Residence in the highest density quartile of healthy food retail establishments compared with the lowest quartile was associated with lower adjusted risk of SGA (with adjustment for individual covariates including gestational weight gain z-score: risk ratio [RR], 0.89; 95% CI 0.83-0.97). Higher neighborhood density of unhealthy food retail establishments was associated with higher adjusted risk of delivering an infant classified as SGA (fourth vs first quartile: RR, 1.12; 95% CI, 1.01-1.24). The RR for the association between density of unhealthy food retail establishments and risk of LGA was higher after adjustment for all covariates in each quartile compared with quartile 1 (second: RR, 1.12 [95% CI, 1.04-1.20]; third: RR, 1.18 [95% CI, 1.08-1.29]; fourth: RR, 1.16; [95% CI, 1.04-1.29]). There were no associations between neighborhood walkability and birth weight outcomes (SGA for fourth vs first quartile: RR, 1.01 [95% CI, 0.94-1.08]; LGA for fourth vs first quartile: RR, 1.06 [95% CI, 0.98-1.14]).

Conclusions and Relevance

In this population-based cross-sectional study, healthfulness of neighborhood food environments was associated with risk of SGA and LGA. The findings support use of urban design and planning guidelines to improve food environments to support healthy pregnancies and birth weight.

An exploration into the influence of birthweight and breastfeeding status on the weight status of 3-year-olds in an Irish cohort

BACKGROUND

Childhood obesity is a growing concern in Ireland. Childhood obesity can increase the risk of developing many non-communicable diseases and have lasting psychological and social consequences.

AIM

The aim of this study is to explore if weight at birth and breastfeeding status influence the weight status of 3-year-olds in an Irish cohort.

METHOD

This retrospective cohort study utilised data (National Child Health Screening Programme) on 3-year-olds born between 1 January 2011 and 3 March 2014 in the North West of Ireland.

RESULTS

Overall, 4144 children were included in the study. The main findings of this study were that 5.4% (n = 222) and 7.1% (n = 296) of the cohort were overweight or obese respectively with a higher percent of males than females in each category. Just under 55% (n = 2266) of the cohort were never breastfed, with only 7.4% breastfed for greater than 6 months. Those born with a high birthweight were more likely to be overweight or obese at 3 years (p ≤ 0.001).

CONCLUSION

These findings provide regionally specific data and highlight the need for focussed public health efforts to reduce the prevalence of overweight and obesity in children aged 3 years in this area. Interventions from pregnancy through childhood are warranted, with an initial emphasis on breast feeding initiation and maintenance.

Childhood obesity and adverse cardiometabolic risk in large for gestational age infants and potential early preventive strategies: a narrative review

Accumulating evidence indicates that obesity and cardiometabolic risks become established early in life due to developmental programming and infants born as large for gestational age (LGA) are particularly at risk. This review summarizes the recent literature connecting LGA infants and early childhood obesity and cardiometabolic risk and explores potential preventive interventions in early infancy. With the rising obesity rates in women of childbearing age, the LGA birth rate is about 10%. Recent literature continues to support the higher rates of obesity in LGA infants. However, there is a knowledge gap for their lifetime risk for adverse cardiometabolic outcomes. Potential factors that may modify the risk in early infancy include catch-down early postnatal growth, reduction in body fat growth trajectory, longer breastfeeding duration, and presence of a healthy gut microbiome. The early postnatal period may be a critical window of opportunity for active interventions to mitigate or prevent obesity and potential adverse metabolic consequences in later life. A variety of promising candidate biomarkers for the early identification of metabolic alterations in LGA infants is also discussed. IMPACT: LGA infants are the greatest risk category for future obesity, especially if they experience rapid postnatal growth during infancy. Potential risk modifying secondary prevention strategies in early infancy in LGA infants include catch-down early postnatal growth, reduction in body fat growth trajectory, longer breastfeeding duration, and presence of a healthy gut microbiome. LGA infants may be potential low-hanging fruit targets for early preventive interventions in the fight against childhood obesity.

What is the "cost" of reducing adverse pregnancy outcomes in patients with gestational diabetes mellitus - risk factors for perinatal complications in a retrospective cohort of pregnant women with GDM

BACKGROUND

Gestational diabetes mellitus (GDM) is a frequent pregnancy complication, affecting the maternal and neonatal health. The new diagnostic strategy for GDM, proposed by the International Association of Diabetes and Pregnancy Study Groups in 2010 and World Health Organization in 2013, raised hope to reduce perinatal complications. The purpose of the study was to compare risk factors influencing maternal and foetal outcomes in a group of pregnant women diagnosed with GDM, and in a group of pregnant women without GDM, regardless of the adopted diagnostic criteria. Also, the aim of the study was to evaluate the impact of risk factors on perinatal results and the "cost" of reducing adverse pregnancy outcomes in patients with GDM.

METHODS

It was a retrospective study based on the analysis of births given after 37 weeks of pregnancy at the 2nd Department of Obstetrics and Gynaecology, Warsaw Medical University during the years 2013 to 2015. All pregnant women had a 75 g OGTT between the 24th and 28th weeks of pregnancy. The study compared risk factors for perinatal complications in 285 GDM patients and in 202 randomly selected women without GDM. The impact of selected risk factors on perinatal outcomes was analysed.

RESULTS

Both the diagnosis of GDM and maternal BMI prior to pregnancy, significantly modified the risk of excessive and insufficient weight gain during pregnancy. The parameters significantly influencing the risk of the composite adverse maternal outcome were the maternal abdominal circumference [OR: 1.08 (1.04; 1.11)] and multiparity, which reduced the risk by almost half [OR: 0.47 (0.30; 0.75)]. The maternal abdominal circumference before the delivery was a strong factor correlating with the occurrence of perinatal complications in both the mother and the foetus in the entire cohort. A circumference over 100 cm increased the risk of at least one maternal complication (increased blood loss, soft tissue injury, pre-eclampsia) by almost 40% (OR 1.38, p < 0.001).

CONCLUSIONS

No differences were found in maternal and foetal outcomes in GDM and non-GDM women except gestational weight gain below Institute of Medicine recommendations. The only "cost" of reducing adverse pregnancy outcomes in GDM patients seems to be lowering gestational weight gain, the future impact of which on GDM pregnant population should be assessed. The maternal abdominal circumference measured before delivery not the severity of carbohydrate intolerance, remained the main predictor for significant perinatal complications.

Relationships between intrauterine fetal growth trajectories and markers of adiposity and inflammation in young adults

BACKGROUND

There is now good evidence that events during gestation significantly influence the developmental well-being of an individual in later life. This study aimed to investigate the relationships between intrauterine growth trajectories determined by serial ultrasound and subsequent markers of adiposity and inflammation in the 27-year-old adult offspring from the Raine Study, an Australian longitudinal pregnancy cohort.

METHODS

Ultrasound fetal biometric measurements including abdominal circumference (AC), femur length (FL), and head circumference (HC) from 1333 mother-fetal pairs (Gen1-Gen2) in the Raine Study were used to develop fetal growth trajectories using group-based trajectory modeling. Linear mixed modeling investigated the relationship between adult body mass index (BMI), waist circumference (WC), and high-sensitivity C-reactive protein (hs-CRP) of Gen2 at 20 (n = 485), 22 (n = 421) and 27 (n = 437) years and the fetal growth trajectory groups, adjusting for age, sex, adult lifestyle factors, and maternal factors during pregnancy.

RESULTS

Seven AC, five FL and five HC growth trajectory groups were identified. Compared to the average-stable (reference) group, a lower adult BMI was observed in two falling AC trajectories: (β = -1.45 kg/m², 95% CI: -2.43 to -0.46, P = 0.004) and (β = -1.01 kg/m², 95% CI: -1.96 to -0.05, P = 0.038). Conversely, higher adult BMI (2.58 kg/m², 95% CI: 0.98 to 4.18, P = 0.002) and hs-CRP (37%, 95% CI: 9-73%, P = 0.008) were observed in a rising FL trajectory compared to the reference group. A high-stable HC trajectory associated with 20% lower adult hs-CRP (95% CI: 5-33%, P = 0.011).

CONCLUSION

This study highlights the importance of understanding causes of the unique patterns of intrauterine growth. Different fetal growth trajectories from early pregnancy associate with subsequent adult adiposity and inflammation, which predispose to the risk of diabetes and cardiometabolic disease.

Breastfeeding and overweight/obesity among children and adolescents: a cross-sectional study

Background

Overweight and obesity are major public health crises among children and adolescents and contribute to a significant economic burden. We aimed to investigate the relationship between breastfeeding duration and overweight and obesity in children and adolescents in Qingdao, China in 2017.

Methods

This study conducted a survey with 10,753 students (5370 boys and 5383 girls) aged 6 to 16 years from the Shibei District of Qingdao, China in 2017. Anthropometric measurements were taken by well-trained personnel and self-completed questionnaires were used to collect data from students. A variety of statistical methods were used in this study, including univariate and multivariate analyses, as well as linear and nonlinear regression models.

Results

The prevalence of overweight and obesity was 15.45% and 19.76%, respectively. There was a significant negative correlation between breastfeeding duration and BMI in children and adolescents (β = -0.025, 95% CI: -0.033, -0.005, P < 0.01). Among boys, the BMI in children and adolescences of those who have been breastfed for more than 12 months was significantly lower than that of others whose breastfeeding duration was less than 12 months (β = -0.440, 95%CI -0.655, -0.224, P < 0.01). Breastfeeding has a particularly positive effect on the prevalence of obesity in boys aged 9 to 11 years (OR = 0.978, 95% CI: 0.958,0.999, P < 0.05).

Conclusion

Breastfeeding can significantly reduce the prevalence of overweight and obesity among children and adolescents aged 6 to 16 years. Those who were breastfed for more than 12 months had a lower risk of developing overweight and obesity, especially boys between the ages of 9 and 11.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03394-z.

Differences in nutritional status between rural and urban Yucatec Maya children: The importance of early life conditions

Early‐life conditions shape childhood growth and are affected by urbanization and the nutritional transition. To investigate how early‐life conditions (across the “first” and “second” 1000 days) are associated with rural and urban children's nutritional status, we analyzed anthropometric data from Maya children in Yucatan, Mexico. We collected weight, height and triceps skinfold measures, then computed body mass and fat mass indices (BMI/FMI), in a cross‐sectional sample of 6‐year‐olds (urban n = 72, rural n = 66). Demographic, socioeconomic and early‐life variables (birthweight/mode, rural/urban residence, household crowding) were collected by maternal interview. We statistically analyzed rural‐urban differences in demographic, socioeconomic, early‐life, and anthropometric variables, then created linear mixed models to evaluate associations between early‐life variables and child anthropometric outcomes. Two‐way interactions were tested between early‐life variables and child sex, and between early‐life variables and rural‐urban residence. Results showed that rural children were shorter‐statured, with lower overweight/obesity and cesarean delivery rates, compared to urban children. Household crowding was a negative predictor of anthropometric outcomes; the strongest effect was in boys and in urban children. Birthweight positively predicted anthropometric outcomes, especially weight/BMI. Birth mode was positively (not statistically) associated with any anthropometric outcome. Cesarean delivery was more common in boys than in girls, and predicted increased height in urban boys. In conclusion, urbanization and household crowding were the most powerful predictors of Maya 6‐year‐old anthropometry. The negative effects of crowding may disproportionately affect Maya boys versus girls and urban versus rural children. Early‐life conditions shape Maya children's nutritional status both in the “first” and “second” 1000 days.

CRITICAL STEPS FOR HUMAN GUT EXFOLIOME RNA PROFILING ANALYSIS USING NON-INVASIVE STOOL SAMPLES

INTRODUCTION

Dietary exposure and drug treatments influence gut cellular pathways and hence growth and potentially even the gut-brain-microbiome axis. Since eukaryotic mRNA presents poly A sequence that distinguishes them from the prokaryotes mRNA, we could analyze the gene expression of human gut cells using exfoliated gut cells available in stool samples. However, the impact of the critical steps of these non-invasive methods must be analyzed.

METHODS

We tested prokaryote contamination in all the steps of different procedures to analyze human exfoliome by microarrays and the influence of the fecal sampling collection process.

RESULTS & CONCLUSION

The least bacterial contamination was found using RNA amplified with oligo dT from GeneChip 3´ IVT Pico Reagent kit or using RNA purified by both Oligotex® + oligodT. RNA later® collection of feces affects the microarray results compared to directly frozen fecal samples, although both methods produce similar cDNA quality. This technique is a potential non-invasive diagnostic tool that can be applied to larger studies to quantify intestinal gene expression in humans with non-invasive samples, but samples should always be collected and analyzed under the same procedure.

Portable HEPA filter air cleaner use during pregnancy and children's body mass index at two years of age: The UGAAR randomized controlled trial

IMPORTANCE

Gestational exposure to particulate matter (PM) air pollution may increase the risk of childhood obesity, but the impact of reducing air pollution during pregnancy on obesity-related outcomes in childhood has not been examined.

OBJECTIVE

To assess the impact of reducing gestational PM exposure on body mass index (BMI) at two years of age.

METHODS

In this single-blind, parallel group randomized controlled trial in Ulaanbaatar Mongolia, we randomly assigned 540 pregnant women to receive 1-2 portable high efficiency particulate air (HEPA) filter air cleaners or no air cleaners. We measured height and weight when children were a mean age of 23.8 months. Our primary outcome was age- and sex-specific BMI z-score based on the World Health Organization 2007 Growth Charts. Secondary outcomes included age- and sex-specific weight z score, overweight/obesity (defined as BMI z-score > 2.00), and catch-up growth (defined using various cut-offs to identify children with relatively low birth weight for sex and gestational age and relatively high age- and sex-specific weight in childhood). We imputed missing outcome data using multiple imputation with chained equations and our primary analysis was by intention to treat (ITT). We estimated intervention effects on continuous and binary outcomes using linear and logistic regression, respectively.

RESULTS

After excluding known miscarriages, still births, and neonatal deaths our analysis included 480 children (235 control and 245 intervention). The mean (SD) child BMI z score was 0.79 (1.0); 9.8% of children were overweight or obese. The mean BMI z score of children who were randomly assigned to the intervention group was 0.16-units lower (95% CI: -0.35, 0.04) than children in the control group. The intervention was also associated with reductions in overweight/obesity (odds ratio = 0.59; 95% CI: 0.31, 1.12). Catch-up growth occurred less frequently in the intervention group, but effect estimates varied depending on the specific definition of catch-up growth and confidence intervals consistently spanned no effect.

CONCLUSIONS

We found that the use of portable air cleaners during pregnancy was associated with improvements in obesity-related outcomes, although some effect estimates lacked precision. Reducing PM exposure during pregnancy may lead to improvements in cardiometabolic health in childhood.

Associations between prepregnancy body mass index, gestational weight gain and weight catch-up in small-for-gestational-age children

Inadequate gestational weight gain (GWG) was related with a higher incidence of small‐for‐gestational‐age (SGA) births than appropriate GWG; however, the long‐term association of maternal GWG with weight catch‐up growth in SGA children remains unknown. The objective of this study is to evaluate the associations between prepregnancy body mass index (pBMI), GWG and weight catch‐up patterns in SGA children. Data were from the Collaborative Perinatal Project, an American multicentre prospective cohort study. A total of 56,990 gravidas were recruited at the first prenatal visit, and children were followed up until school age. Maternal pBMI, GWG and physical growth of the offspring at birth, 4 months, 1 year, 4 years and 7 years old were recorded. The latent class analysis was employed to form weight catch‐up growth patterns (appropriate, excessive, slow, regression and no catch‐up patterns) in SGA children. SGA children who developed the ‘appropriate catch‐up growth’ pattern and whose mothers had appropriate pBMI and GWG were chosen as the reference. Associations between GWG for different pBMI and weight catch‐up patterns were analysed by multivariate logistic regression models. A total of 1619 infants (9.45%) were born term SGA. After adjusting for relevant confounders, compared with SGA children whose mothers had appropriate pBMI and GWG, SGA children with maternal prepregnancy underweight (for inadequate GWG, GWG below recommendations, adjusted OR: 2.88, 95% CI: 1.13–7.31; for appropriate/excessive GWG, adjusted OR: 3.07, 95% CI: 1.74–5.42) or with prepregnancy normal weight but inadequate GWG (adjusted OR: 2.14, 95% CI: 1.36–3.38) were at a higher risk of having the ‘no catch‐up growth’ pattern. We suggest that SGA children with maternal prepregnancy underweight or inadequate GWG tend to have a poor weight catch‐up growth at least until school age.

Levels of Predominant Intestinal Microorganisms in 1 Month-Old Full-Term Babies and Weight Gain during the First Year of Life

The early life gut microbiota has been reported to be involved in neonatal weight gain and later infant growth. Therefore, this early microbiota may constitute a target for the promotion of healthy neonatal growth and development with potential consequences for later life. Unfortunately, we are still far from understanding the association between neonatal microbiota and weight gain and growth. In this context, we evaluated the relationship between early microbiota and weight in a cohort of full-term infants. The absolute levels of specific fecal microorganisms were determined in 88 vaginally delivered and 36 C-section-delivered full-term newborns at 1 month of age and their growth up to 12 months of age. We observed statistically significant associations between the levels of some early life gut microbes and infant weight gain during the first year of life. Classifying the infants into tertiles according to their Staphylococcus levels at 1 month of age allowed us to observe a significantly lower weight at 12 months of life in the C-section-delivered infants from the highest tertile. Univariate and multivariate models pointed out associations between the levels of some fecal microorganisms at 1 month of age and weight gain at 6 and 12 months. Interestingly, these associations were different in vaginally and C-section-delivered babies. A significant direct association between Staphylococcus and weight gain at 1 month of life was observed in vaginally delivered babies, whereas in C-section-delivered infants, lower Bacteroides levels at 1 month were associated with higher later weight gain (at 6 and 12 months). Our results indicate an association between the gut microbiota and weight gain in early life and highlight potential microbial predictors for later weight gain.

Prenatal exposure to air pollutants and early childhood growth trajectories: A population-based prospective birth cohort study

BACKGROUND

Air pollution exposure during pregnancy has been documented to be associated with impaired fetal growth and adverse birth outcomes, but the evidence regarding the effects of air pollution on early childhood growth is still limited.

OBJECTIVE

We aimed to explore the associations of exposure to air pollutants during pregnancy with childhood growth trajectories from birth to age of 6 years.

METHODS

A prospective cohort study based on the administrative registration system was conducted covering 62,540 births in Wuhan, China between January 1, 2011 and December 31, 2013 and followed for 6 years. Inverse distance weighted method was used to estimate the concentrations of air pollutants exposure for pregnant women. Group-based trajectory models (GBTM) were used to identify growth patterns of children: slow growth, normal growth, and rapid growth. Multinomial logistic regression models were used to examine the associations between prenatal exposure to air pollutants and childhood growth trajectories with adjustment for maternal age, educational status, pre-pregnancy BMI, residential areas, gestational diabetes, birth type, gender of infant, and breastfeeding duration.

RESULTS

The mean (SD) of prenatal exposure concentrations for PM₁₀, SO₂, NO₂, CO, and O₃ were 107.9 (30.4), 32.8(12.6), 55.8(13.1), 1081.2(293.1), and 81.6(31.0) μg/m³ respectively. Compared with normal growth trajectory, increased PM₁₀ and CO exposure were significantly associated with higher risk of slow growth trajectory but lower risk of rapid growth trajectory. An increase in prenatal exposure to NO₂ significantly increased both the risk of slow growth trajectory and rapid growth trajectory. Increased prenatal SO₂ exposure was significantly associated with rapid growth trajectory and was not associated with low growth trajectory. With O₃ exposure levels increased, risk to be rapid growth trajectory decreased. Prenatal air pollutants exposure had a greater impact on childhood growth of children who were girls, and those mothers lived in rural areas and were normal weight before pregnancy.

CONCLUSIONS

High levels of air pollutants exposure during pregnancy were associated with the risk of being in a trajectory with the deviation of BMI gain from birth to 6 years old. These findings suggest that efforts to identify children at risk of growth deviation in early childhood should pay attention to environmental exposure during pregnancy for their mothers.

Combined effects of weight change trajectories and eating behaviors on childhood adiposity status: A birth cohort study

Previous studies have suggested that infant rapid weight change can be associated with an increased weight later in life. However, the weight change trajectory in early life over time and which childhood lifestyle behaviors may modify the risk of rapid weight change have not been characterized. Using our ongoing birth cohort study, we have addressed these issues. Nine follow-up time points (birth, 3, 6, 9, 12, 18, 24, 36, and 48 months) were used to calculate the change between two adjacent weight-for-age z-scores (WAZ-change), and then WAZ-change trajectories were defined via group-based trajectory modeling. The solitary, independent and combined effects of WAZ-change trajectories and each lifestyle factor (eating behaviors, physical activity, media exposure time and total sleep duration) on childhood adiposity measures at age 4 years were determined using multivariate regression analysis. Overall, 84 (38%) children had a steady growth trajectory from birth to 4 years, while the other 137 (62%) children had an early infancy rapid growth trajectory, particularly in the first three months. Compared to children with steady growth, children with early infancy rapid growth had a significantly higher body mass index, waist circumference, and subcutaneous fat. Moreover, weight change trajectory and three eating behaviors (i.e. food responsiveness, satiety responsiveness and food fussiness), not only had independent effects, but also combined (synergistic) effects on the majority of adiposity measures. Our results extend the current literature and provide a potentially valuable model to aid clinicians and health professionals in designing early-life interventions targeting specific populations, specific ages and specific lifestyle behaviors to prevent childhood overweight/obesity.

Fetal growth does not modify the relationship of infant weight gain with childhood adiposity and blood pressure in the Southampton women's survey

Background: Rapid infant weight gain is a risk factor for childhood obesity. This relationship may depend on whether infant weight gain is preceded by in-utero growth restriction.

Aim: Examine whether fetal growth modifies the relationship between infant weight gain and childhood adiposity and blood pressure.

Subjects and methods: 786 children in the Southampton Women’s Survey. We related infant weight gain (weight at 2 years-birth weight) to body mass index (BMI), %body fat, trunk fat (kg), systolic (SBP) and diastolic blood pressure (DBP) at age 6–7 years. Mean estimated fetal weight (EFW) between 19–34 weeks and change in EFW (19–34 weeks) were added to models as effect modifiers.

Results: Infant weight gain was positively associated with all childhood outcomes. We found no evidence that these effects were modified by fetal growth (p > .1 for all interaction terms). For example, a 1 standard deviation (SD) increase in infant weight gain was associated with an increase in BMI z-score of 0.51 (95% CI 0.37;0.64) when EFW-change was set at -2 SD-scores compared with an increase of 0.41 (95% CI 0.27;0.54, p_{(interaction)}=.48) when set at 2 SD-scores.

Conclusion: The documented adverse consequences of rapid infant weight gain may occur regardless of whether growth was constrained in-utero.

Obesity prevention in the early years: A mapping study of national policies in England from a behavioural science perspective

Background

Evidence indicates that early life is critical for determining future obesity risk. A sharper policy focus on pregnancy and early childhood could help improve obesity prevention efforts. This study aimed to systematically identify and categorise policy levers used in England with potential to influence early life course (pregnancy, 0–5 years) and identify how these interface with energy balance behaviours. The objective is to identify gaps and where further policy actions could most effectively focus.

Methods

A behavioural science approach was taken using the Capability-Opportunity-Motivation-Behaviour (COM-B) model and Behaviour Change Wheel (BCW) framework. The key determinants of energy balance in the early years were identified from the Foresight Systems Map. Policy actions were scoped systematically from available literature, including any health or non-health policies which could impact on energy balance behaviours. Foresight variables and policy actions were considered in terms of COM-B and the BCW to determine approaches likely to be effective for obesity prevention and treatment. Existing policies were overlaid across the map of key risk factors to identify gaps in obesity prevention and treatment provision.

Results

A wide range of policy actions were identified (n = 115) to address obesity-relevant risk factors. These were most commonly educational or guidelines relating to environmental restructuring (i.e. changing the physical or social context). Scope for strengthening policies relating to the food system (e.g. the market price of food) and psychological factors contributing to obesity were identified. Policies acted via all aspects of the COM-B model, but there was scope for improving policies to increase capability through skills acquisition and both reflective and automatic motivation.

Conclusions

There is substantial policy activity to address early years obesity but much is focused on education. Scope exists to strengthen actions relating to upstream policies which act on food systems and those targeting psychological factors contributing to obesity risk.

Prenatal Ambient Particulate Matter Exposure and Longitudinal Weight Growth Trajectories in Early Childhood

Air pollution exposure during pregnancy has been associated with impaired fetal growth and postnatal weight gain, but few studies have examined the effect on weight growth trajectories. We examine the association between validated 1 km² resolution particulate matter (PM_2.5) concentrations, averaged over pregnancy, and sex-specific growth trajectories from birth to age six of participants in the Boston-based Children's HealthWatch cohort (4797 participants, 84,283 measures). We compared weight trajectories, predicted using polynomial splines in mixed models, between prenatal PM_2.5 above or below the median (9.5 µg/m³), and examined birth weight as an effect modifier. Females exposed to average prenatal PM_2.5 ≥ 9.5 µg/m³ had higher weights compared to females exposed to < 9.5 µg/m³ throughout the study period (0.16 kg at 24 months, 0.61 kg at 60 months). In males, higher prenatal PM_2.5 exposure was associated with significantly lower weights after 24 months of age, with differences increasing with time (-0.17 at 24 months, -0.72 kg at 60 months). Associations were more pronounced among low birth weight (<2500 g) females, but did not differ by birth weight status in males. Our findings demonstrate the complex association between air pollution exposures and childhood weight trajectories and emphasize the importance of sex-stratified analyses.

Steady Growth in Early Infancy Is Associated with Greater Anthropometry in Indian Children Born Low Birth Weight at Term

BACKGROUND

Patterns of early growth are associated with later body composition and risk of adult noncommunicable disease but information from low-income countries is limited.

OBJECTIVES

The aim of this study was to investigate early growth trajectories and later anthropometric and bone density outcomes among children born term low birth weight (LBW: 1.8-2.5 kg).

METHODS

We used data from 902 children from the Delhi Infant Vitamin D Supplementation study of LBW term infants (which collected monthly anthropometry from birth to 6 mo) and who had height, weight, midupper arm circumference (MUAC), midupper arm muscle circumference (MUAMC), subscapular and triceps skinfold thicknesses, tibia and radius bone density measured at age 4-6 y. We investigated how growth in the first 6 mo of life, modeled using the SuperImposition by Translation and Rotation (SITAR) growth curve model, was related to these outcomes. SITAR summarizes each infant's weight and length trajectory in terms of a population mean curve and child-specific growth parameters: size, timing, and intensity. These were included as explanatory variables in linear regression models for the childhood outcomes.

RESULTS

Considering the infant weight and length SITAR parameters jointly, childhood weight was strongly associated with infant length timing [estimated regression coefficient β = 0.25 (95% CI: 0.10, 0.39)] and with weight size, timing, and intensity [β = 9.01 (6.75, 11.27), β = -0.25 (-0.43, -0.07), β = 5.03 (3.22, 6.84), respectively]. Childhood height was associated only with the length parameters [β = 0.97 (0.71, 1.23), β = -0.43 (-0.77, -0.09), β = 11.68 (8.60, 14.75), respectively]; childhood MUAC, MUAMC, and skinfolds with all parameters; and bone density with none. Overall, delayed and sustained growth in infant weight and length resulted in higher values of all outcomes except bone density, with the period up to 15 wk of age appearing critical for setting childhood anthropometry in this population.

CONCLUSIONS

The explanation for the effects of delayed growth and length of the period in which trajectories are set is unclear; however, sustained and delayed growth in early infancy appears to be beneficial for these LBW children at least in the short-term. The trial was registered at clinicaltrials.gov as BT/PR7489/PID/20/285/2006.

Pacific Islands Families Study: Physical growth to age 14 and metabolic risk

BACKGROUND

The relationships between the trajectories of weight gain from early childhood to adolescence and risk for metabolic disease are not well understood.

OBJECTIVE

The objective of the study is to examine the relationships between weight gain from 2 to 14 years and metabolic risk factors at age 14 years in Pacific Island children.

METHODS

z scores for weight were calculated at each of the ages 2.5, 4, 6, 9, 11, and 13.5 years in 1053 children. Growth trajectories were determined by estimating the linear trend of z scores with age for each child. In a subgroup of 204 children, biomarkers of metabolic risk were measured and related to linear trend intercepts and slopes.

RESULTS

More rapid growth (greater slope of z score trajectory) was associated with higher concentrations of insulin, leptin (boys), urate, and markers of liver function, insulin resistance and inflammation. Children with higher weights in early life (greater intercept) showed fewer associations with metabolic markers, but considered together, intercept and slope were independently associated with a range of metabolic risk factors.

CONCLUSIONS

Both rapid weight gain and a higher body weight in early childhood were associated with higher risk for metabolic disease. Monitoring growth trajectories may help target interventions to optimize nutrition, physical activity, and growth.

Associations between maternal age at menarche and anthropometric and metabolic parameters in the adolescent offspring

OBJECTIVE

We examined the associations between maternal age at menarche and anthropometry and metabolism in adolescent offspring.

METHODS

Anthropometric, metabolic and blood pressure data were obtained from 304 girls and 190 boys aged 11-16 years attending school in Hangzhou (China). Age at menarche for both mothers and daughters was self-reported. Fasting blood samples were obtained and all participants underwent clinical examinations. Obesity was defined as BMI ≥95th percentile for age and sex.

RESULTS

Older maternal age at menarche was associated with older age of their daughters at menarche (r = 0.21; P < 0.001). Mother's age at menarche was not associated with anthropometry or metabolism of daughters. However, younger maternal age at menarche was associated with increased hip and waist circumferences, and BMI SDS of their sons. Boys whose mothers were ≤13 years at menarche had an adjusted relative risk of obesity 3-fold greater than sons of mothers with a later menarcheal onset (2.96; 95% CI 1.49, 5.87). Among daughters, every 1-year increase in their age at menarche was associated with a 0.34 SDS reduction in BMI. Increasing age at menarche was also associated with reduced waist and hip circumferences (-1.5 and -1.8 cm/y, respectively) and waist-to-height ratio (-0.008 per year). Girls in the youngest menarcheal age tertile (8.8-11.6 years) had diastolic blood pressure 2.2 mm Hg higher than other girls (P = 0.029).

CONCLUSIONS

Younger maternal age at menarche is associated with increased obesity risk in their sons, but not daughters. However, girls who experience menarche earlier have a less favourable anthropometric profile.

Associations of Fetal and Infant Weight Change With General, Visceral, and Organ Adiposity at School Age

IMPORTANCE

Both fetal and infant growth influence obesity later in life. The association of longitudinal fetal and infant growth patterns with organ fat is unknown.

OBJECTIVE

To examine the associations of fetal and infant weight change with general, visceral, and organ adiposity at school age.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was embedded in the Generation R Study, a population-based prospective cohort study in Rotterdam, the Netherlands. Pregnant women with a delivery date between April 2002 and January 2006 were eligible to participate. Follow-up measurements were performed for 3205 children. Data analysis of this population was performed from July 26, 2018, to February 7, 2019.

EXPOSURES

Fetal weight was estimated in the second and third trimester of pregnancy. Infant weight was measured at 6, 12, and 24 months. Fetal and infant weight acceleration or deceleration were defined as a change in standard deviation scores greater than 0.67 between 2 ages.

MAIN OUTCOMES AND MEASURES

Visceral fat index, pericardial fat index, and liver fat fraction were measured by magnetic resonance imaging.

RESULTS

The sample consisted of 3205 children (1632 girls [50.9%]; mean [SD] age, 9.8 [0.3] years). Children born small for gestational age had the lowest median body mass index compared with children born appropriate for gestational age and large for gestational age (16.4 [90% range, 14.1-23.6] vs 16.9 [90% range, 14.4-22.8] vs 17.4 [90% range, 14.9-22.7]). Compared with children with normal fetal and infant growth (533 of 2370 [22.5%]), those with fetal weight deceleration followed by infant weight acceleration (263 of 2370 [11.1%]) had the highest visceral fat index (standard deviation scores, 0.18; 95% CI, 0.03-0.33; P = .02) and liver fat fraction (standard deviation scores, 0.34; 95% CI, 0.20-0.48; P < .001).

CONCLUSIONS AND RELEVANCE

Fetal and infant weight change patterns were both associated with childhood body fat, but weight change patterns in infancy tended to have larger effects. Fetal growth restriction followed by infant growth acceleration was associated with increased visceral and liver fat.

Does breast milk adiponectin affect BMI and cardio-metabolic markers in childhood?

Observational studies suggest that breast-feeding is associated with a more favourable BMI and cardio-metabolic markers, but potential underlying mechanisms are unclear. As serum adiponectin has an important function in adults for glucose and lipid metabolism, we assessed 251 participants of the Prevention and Incidence of Asthma and Mite Allergy birth cohort whether breast milk adiponectin is associated with childhood BMI and cardio-metabolic markers. We measured adiponectin levels in breast milk collected around 3 months after birth of the child and subsequently obtained weight and height repeatedly up to the age of 17 years. A medical examination (including blood pressure, glycated Hb and cholesterol) was performed at the age of 8, 12 and 16 years. We used multivariable mixed models to assess the association between breast milk adiponectin and BMI and cardio-metabolic markers at these ages. In models adjusted for exact age of breast milk collection, maternal age, presence of siblings, maternal BMI, pregnancy weight gain and child's birth weight, each unit increase in log breast milk adiponectin (in ng/ml) was associated with a 0·28 lower BMI z score (95 % CI -0·56, 0·00) at 3 months. After the age of 1 year, there was a tendency towards a higher BMI z score with increased breast milk adiponectin at some ages, but this pattern was not consistent throughout childhood. There were no associations between breast milk adiponectin and any of the cardio-metabolic markers in childhood. We conclude that in our study with follow-up until 17 years of age, breast milk adiponectin has no long-term effect on BMI and cardio-metabolic health during childhood.

Early Childhood Obesity Risk Factors: Socioeconomic Adversity, Family Dysfunction, Offspring Distress, and Junk Food Self-Medication

PURPOSE OF REVIEW

To explore the sequence and interaction of infancy and early childhood risk factors, particularly relating to disturbances in the social environment, and how the consequences of such exposures can promote weight gain and obesity.

RECENT FINDINGS

This review will argue that socioeconomic adversity is a key upstream catalyst that sets the stage for critical midstream risk factors such as family strain and dysfunction, offspring insecurity, stress, emotional turmoil, low self-esteem, and poor mental health. These midstream risk factors, particularly stress and emotional turmoil, create a more or less perfect foil for calorie-dense junk food self-medication and subtle addiction, to alleviate uncomfortable psychological and emotional states. Disturbances in the social environment during infancy and early childhood appear to play a critical role in weight gain and obesity, through such mechanisms as insecurity, stress, and emotional turmoil, eventually leading to junk food self-medication and subtle addiction.

Breastfeeding duration, maternal body mass index, and birth weight are associated with differences in body mass index growth trajectories in early childhood

Background

Accelerated postnatal growth is an important predictor for obesity risk. It is unknown whether early-life obesity-related risk factors affect body mass index (BMI) growth rates during distinct growth periods from early infancy through preschool years.

Objective

We examined whether breastfeeding duration, maternal BMI, and birth weight are associated with growth trajectories of age- and sex-standardized WHO BMI z scores (zBMIs) in young children.

Design

Children (n = 5905) in The Applied Research Group for Kids (TARGet Kids!) prospective cohort study underwent repeated measures of weight and length or height from birth to 10 y of age. Piecewise linear mixed models were used to determine whether zBMI growth rates differ for each risk factor during periods of growth between birth and 1, 3, 18, 36, and 72 mo of age.

Results

Children who were breastfed <6 mo compared with ≥6 mo showed a higher growth rate between 1-3 and 3-18 mo, resulting in higher standardized BMIs (zBMIs) of +0.24, +0.12, and +0.19 at 18, 36, and 72 mo, respectively. Maternal BMI (in kg/m2) ≥30 compared with <30 resulted in higher growth rates between 1-3 and 36-72 mo and higher zBMIs of +0.22, +0.14, +0.18, and +0.41 at 3, 18, 36, and 72 mo, respectively. Infants weighing <2.5 kg at birth (compared with 2.5-4 kg) experienced higher growth rates between 1-3 and 3-18 mo but had lower zBMIs at all time points (zBMI: -1.45 to -0.21). Infants weighing ≥4 kg at birth (compared with 2.5-4 kg) had significantly lower growth rates in the first 3 mo but higher zBMIs at all time points (zBMI: +1.16 to +0.27).

Conclusion

Differences in zBMI growth rates by breastfeeding duration, maternal BMI, and birth weight are seen in early infancy and contribute to differences in zBMI, which persist into midchildhood. This trial was registered at www.clinicaltrials.gov as NCT01869530.