Effects of prolonged and exclusive breastfeeding on child height, weight, adiposity, and blood pressure at age 6.5 y: evidence from a large randomized trial

Novel mechanisms involved in leptin sensitization in obesity

Leptin is a hormone that is secreted by adipocytes in proportion to adipose tissue size, and that informs the brain about the energy status of the body. Leptin acts through its receptor LepRb, expressed mainly in the hypothalamus, and induces a negative energy balance by potent inhibition of feeding and activation of energy expenditure. These actions have led to huge expectations for the development of therapeutic targets for metabolic complications based on leptin-derived compounds. However, the majority of patients with obesity presents elevated leptin production, suggesting that in this setting leptin is ineffective in the regulation of energy balance. This resistance to the action of leptin in obesity has led to the development of "leptin sensitizers," which have been tested in preclinical studies. Much research has focused on generating combined treatments that act on multiple levels of the gastrointestinal-brain axis. The gastrointestinal-brain axis secretes a variety of different anorexigenic signals, such as uroguanylin, glucagon-like peptide-1, amylin, or cholecystokinin, which can alleviate the resistance to leptin action. Moreover, alternative mechanism such as pharmacokinetics, proteostasis, the role of specific kinases, chaperones, ER stress and neonatal feeding modifications are also implicated in leptin resistance. This review will cover the current knowledge regarding the interaction of leptin with different endocrine factors from the gastrointestinal-brain axis and other novel mechanisms that improve leptin sensitivity in obesity.

"Mother's milk": Is there a social reversal in breastfeeding practices along with economic development?

Previous studies suggest that macro- and micro-level factors jointly influence breastfeeding (BF) practices, but empirical evidence on the dynamics of such interactions along with the process of a country's economic development remains limited. Based on 42 Demographic Health Surveys (DHS) conducted in 15 Asian countries with a large time window (1990-2017), we thus test the existence of a reversal in the association between household wealth and BF practices throughout the development process. Four BF indicators (early initiation of BF, exclusive BF, continued BF at one year and two years) are examined, along with a standardized asset-based household wealth index allowing for cross-wave and cross-country comparisons. To highlight the dynamics of the wealth-BF association, we carry out econometric estimations, including interaction terms between household wealth and the country's level of economic development (low, medium, and high) or time. Instrumental variable estimations are also performed to limit suspected endogeneity issues. Our results confirm a transition in the wealth gradient of exclusive BF and continued BF in Asian countries. More precisely, while these practices are pro-poor in the poorest countries of the sample, they progressively spread to wealthier households along with the level of economic development. For exclusive BF, this transition has resulted in a reversal of the wealth gradient at the end of the period (i.e., exclusive BF prevalence among the rich overpassing that of the poor). We fail, however, to observe this kind of transition for early initiation of BF, this practice remaining pro-poor, whatever the level of economic development. To sum up, our results provide robust evidence of a transition in the wealth gradient of some BF practices along with economic development and time, and thus largely echo the literature exploring the social reversal hypothesis in the case of non-communicable diseases.

Variation in maternal lactation practices associated with changes in diurnal maternal inflammation

While the importance of human milk in shaping infant immune function is well established, the impact of at-the-nipple (ATN) breastfeeding on maternal immune status has been understudied. Since lactation evolved to support infant survival and boost maternal fitness, we predict that ATN breastfeeding will confer benefits on maternal immune function. We measure the absolute and relative frequency of different infant feeding methods (ATN breastfeeding, pumping, donated milk, other supplementation) used by postpartum women in Seattle, WA (USA). We implement Bayesian modeling to estimate the effects of ATN breastfeeding on diurnal change in secretion rate of "pro-inflammatory" salivary cytokines and C-reactive protein (CRP). Our results show that most mothers in our sample used a variety of infant feeding methods, with pumping as the most common alternative to ATN breastfeeding. We find that ATN breastfeeding is associated with non-linear effects on diurnal IL-8 and CRP. Furthermore, we find that women who report zero versus ubiquitous ATN breastfeeding exhibit opposing diurnal patterns in CRP secretion rate. This study provides evidence that variation in maternal lactation practices corresponds to differences in maternal immune responses, highlighting how measuring lactation as a continuous variable can further enhance understanding of postpartum maternal physiology.

Ethical Issues in Breastfeeding and Lactation Interventions: A Scoping Review

BACKGROUND

Infant feeding interventions that promote and support breastfeeding are considered important contributions to global public health. As these interventions often target private settings (e.g., individuals' homes) and involve vulnerable populations (e.g., pregnant women, infants, and underprivileged families), a keen awareness of ethical issues is crucial.

RESEARCH AIM

The purpose of this scoping review was to capture the key elements of the current ethical discourse regarding breastfeeding and lactation interventions.

METHOD

A scoping review was conducted using Arksey and O'Malley's (2005) methodology to identify the ethical issues of breastfeeding and lactation interventions as they are reflected in the scholarly literature published between January 1990 and October 2022. Abstracts (N = 3715) from PubMed, ScienceDirect, JSTOR and the Cochrane Database of Systematic Reviews were screened. The final sample consisted of 26 publications.

RESULTS

The recurring ethical issues identified in these studies were: the normative assumptions of motherhood; maternal autonomy and informed choice; information disclosure, balancing risks and benefits, and counseling practices; stigma and social context; ethics of health communication in breastfeeding campaigns; and the ethical acceptability of financial incentives in breastfeeding interventions.

CONCLUSION

This review illustrated that, while a wide range of ethical arguments were examined, the emphasis has been primarily on accounting for mothers' experiences and lactating persons' choices, as well as achieving public health objectives relating to infant nutrition in breastfeeding interventions. To effectively and ethically implement breastfeeding and lactation interventions, we must consider the social, economic, and cultural contexts in which they occur. One key learning identified was that women's experiences were missing in these interventions and, in response, we suggest moving beyond the dichotomous approach of individual health versus population health.

Breastfeeding Duration and Cardiometabolic Health during Adolescence: A Longitudinal Analysis

OBJECTIVE

To investigate the longitudinal association between breastfeeding duration and cardiometabolic health, using repeated measures study design among children and adolescents.

STUDY DESIGN

This study included 634 offsprings aged 10 to 21 years (52% female) from the Early Life Exposure in Mexico to Environmental Toxicants birth cohort followed up to four time points during adolescence. Breastfeeding duration was prospectively quantified using questionnaires during early childhood. Cardiometabolic risk factors, body composition, and weight-related biomarkers were assessed as outcomes during adolescent follow-up visits. Sex-stratified linear mixed-effects models were used to model the association between quartiles of breastfeeding duration and outcomes, adjusting for age and additional covariates.

RESULTS

Median breastfeeding duration was 7 months (minimum = 0, maximum = 36). Boys in the second quartile (median breastfeeding = 5 months) had lower total fat mass % (β (SE) -3.2 (1.5) P = .037), and higher lean mass % (3.1 (1.6) P = .049) and skeletal muscle mass % (1.8 (0.8) P = .031) compared with the reference group (median breastfeeding = 2 months). A positive linear trend between breastfeeding duration and trunk lean mass % (0.1 (0.04) P = .035) was found among girls. No association was found with other cardiometabolic indicators.

CONCLUSION

Despite sex-specific associations of breastfeeding duration with body composition, there was a lack of substantial evidence for the protective effects of breastfeeding against impaired cardiometabolic health during adolescence among Mexican youth. Further longitudinal studies with a robust assessment of breastfeeding are recommended.

Maternal Pre-Pregnancy BMI, Breastfeeding, and Child BMI

OBJECTIVES

Breastfeeding practices may protect against offspring obesity, but this relationship is understudied among women with obesity. We describe the associations between breastfeeding practices and child BMI for age z-score (BMIz), stratified by maternal BMI.

METHODS

We analyzed 8134 dyads from 21 cohorts in the Environmental Influences on Child Health Outcomes Program. Dyads with data for maternal pre-pregnancy BMI, infant feeding practices, and ≥1 child BMI assessment between the ages of 2 and 6 years were included. The associations between breastfeeding practices and continuous child BMIz were assessed by using multivariable linear mixed models.

RESULTS

Maternal pre-pregnancy BMI category prevalence was underweight: 2.5%, healthy weight: 45.8%, overweight: 26.0%, and obese: 25.6%. Median child ages at the cessation of any breastfeeding and exclusive breastfeeding across the 4 BMI categories were 19, 26, 24, and 17 weeks and 12, 20, 17, and 12 weeks, respectively. Results were in the hypothesized directions for BMI categories. Three months of any breastfeeding was associated with a lower BMIz among children whose mothers were a healthy weight (-0.02 [-0.04 to 0.001], P = .06), overweight (-0.04 [-0.07 to -0.004], P = .03), or obese (-0.04 [-0.07 to -0.006], P = .02). Three months of exclusive breastfeeding was associated with a lower BMIz among children whose mothers were a healthy weight (-0.06 [-0.10 to -0.02], P = .002), overweight (-0.05 [-0.10 to 0.005], P = .07), or obese (-0.08 [-0.12 to -0.03], P = .001).

CONCLUSIONS

Human milk exposure, regardless of maternal BMI category, was associated with a lower child BMIz in the Environmental Influences on Child Health Outcomes cohorts, supporting breastfeeding recommendations as a potential strategy for decreasing the risk of offspring obesity.

Caregiver Influences on Eating Behaviors in Children: An Opportunity for Preventing Obesity

PURPOSE OF REVIEW

This review seeks to define caregiver practices that impact childhood eating behaviors and identify ways to utilize these relationships to prevent childhood obesity.

RECENT FINDINGS

Childhood obesity, which correlates with adult obesity and increased cardiovascular risk, is increasing in prevalence and severity. Caregivers play a significant role in shaping a child's eating behaviors and their predisposition to obesity. Maternal influences during pregnancy and infancy impact a child's future food preferences. Caregiver feeding styles (authoritarian, authoritative, indulgent, and uninvolved) are associated with distinct effects on children's eating behaviors and self-regulation. Authoritative feeding styles promote child autonomy while setting boundaries in the feeding environment. Early caregiver education and coaching regarding nutrition and feeding practices is beneficial to establishing healthy eating behaviors for children. Various caregivers, including parents, grandparents, siblings, teachers, and others, influence a child's eating habits at different stages of development. These caregivers can both positively and negatively impact a child's diet. Comprehensive interventions involving these various caregivers to promote healthy eating practices in children is ideal. Such interventions should be sensitive to cultural and environmental factors. Childhood obesity is a complex issue with long-term health effects. Early intervention using comprehensive approaches including all caregivers, community support, and public policies to address the social determinants of health will be beneficial. Future research should focus on valid outcome measures and equitable interventions that encompass all aspects of a child's life.

Breastfeeding is associated with reduced risks of central obesity and hypertension in young school-aged children: a large, population-based study

BACKGROUND

Previous studies examined the effects of breastfeeding on measured values of body circumferences or blood pressure during childhood. However, limited data are available for the association between child feeding and a specific disease diagnosed as central obesity or hypertension. Hence, we aimed to examine whether the type and duration of breastfeeding are associated with obesity/central obesity or hypertension in young school-aged children.

METHODS

We matched the data obtained from a cross-sectional survey in 2019 with retrospective breastfeeding information recorded in the database. Heights, weights, waist circumferences, and blood pressures of 8480 children in first grade of primary schools in Shanghai, China were measured to diagnose obesity, central obesity, and hypertension. Data on child feeding was collected retrospectively from clinical records. Associations between the type/duration of breastfeeding and children's measured values of body mass index, waist circumference, and blood pressure were analysed by linear regression. Associations between the type/duration of breastfeeding and risks of obesity, central obesity, and hypertension were analysed by generalised linear models.

RESULTS

Breastfeeding duration was inversely associated with blood pressure values in children in the first grade. Each month's increase in the duration of any breastfeeding was associated with a 0.07 mmHg decrease in systolic blood pressure (P < 0.01) and a 0.05 mmHg decrease in diastolic blood pressure (P < 0.01). Any breastfeeding > one month was associated with a reduced risk of hypertension (adjusted risk ratio 0.84; 95% CI 0.73, 0.96, P = 0.01). Exclusive breastfeeding > one month was associated with a reduced risk of central obesity (adjusted risk ratio 0.76; 95% CI: 0.60, 0.96, P = 0.02). Any breastfeeding > 12 months was linked with a lower risk of hypertension (adjusted risk ratio 0.83; 95% CI 0.70, 0.98, P = 0.03).

CONCLUSIONS

Lack of breastfeeding is associated with higher risks of central obesity and hypertension during middle childhood. As a potential component of the public health strategy to reduce population levels of metabolic and cardiovascular diseases, breastfeeding could be a vital prevention strategy.

Breastfeeding and ApoB in late adolescence: a Hong Kong birth cohort study

Breastfeeding is widely promoted. Experimental evidence concerning long-term benefits is limited. Observational studies are open to bias from confounding by socio-economic position. We assessed the association of breastfeeding with late adolescent lipid sub-fractions, particularly apolipoprotein B (ApoB) and non-high-density lipoprotein cholesterol (non-HDL-c), overall and by sex. We took advantage of a setting where breastfeeding has little association with higher socio-economic position and where several results from randomized controlled trials of breastfeeding promotion have been replicated. We used the population-representative "Children of 1997" birth cohort comprising 88% of births in Hong Kong in April and May 1997. Associations of breastfeeding in the first 3 months of life (never, mixed, exclusive) with lipid sub-fractions were obtained using linear regression adjusted for potential confounders including parental socio-economic position, maternal place of birth, type of delivery, gestational age, and birth weight. Differences by sex were assessed. Multiple imputation and inverse probability weighting were used to recover the original sample. Of the 3462 participants included, mean age was 17.6 years and 48.8% were girls. Mean ApoB was 0.74 g/L (standard deviation 0.15). Exclusive versus never breastfeeding was associated with lower ApoB (-0.027 g/L, 95% confidence interval (CI)-0.046 to-0.007, p = 0.007) and lower non-HDL-c (-0.143 mmol/L, 95% CI-0.237 to-0.048) with similar estimates by sex.

CONCLUSION

Breastfeeding may provide some population-level lifelong protection against cardiovascular disease. This study supports policies promoting breastfeeding as a modifiable exposure that contributes to a healthy start in life as an investment for lifelong cardiovascular disease prevention.

WHAT IS KNOWN

• Apolipoprotein B (ApoB) is a recognized risk factor for cardiovascular disease, but whether breastfeeding affects ApoB in later life overall and by sex is unknown.

WHAT IS NEW

• Exclusive breastfeeding in the first 3 months of life was associated with lower ApoB in late adolescence, with similar estimates for both sexes. • The inverse association of breastfeeding with ApoB suggests that breastfeeding could reduce cardiovascular disease and overall mortality over the lifespan.

Infant Feeding Pattern Clusters Are Associated with Childhood Health Outcomes

(1) Background: Feeding behavior habits have a pattern with a certain tendency during infancy. We aimed to identify the associations between feeding patterns in infancy and the subsequent 10-year childhood disease burden. (2) Methods: Data from 236,372 infants were obtained from the national health insurance and screening program records in South Korea. Parent-administered questionnaires during infancy provided details on the feeding type and types/frequency of complementary food for analyzing feeding patterns. The outcomes were all-cause hospitalization and the development of 15 representative childhood diseases until the age of 10 years. Anthropometric measurements obtained at 6 years of age were analyzed. To estimate outcome risks while considering multiple risk factors, we employed a Cox proportional hazard and modified Poisson regression. (3) Results: Three clusters were identified: high prevalence of breastfeeding with regular exposure to a variety of solid foods (n = 116,372, cluster 1), similar prevalence of breastfeeding and formula feeding with less exposure to solid foods (n = 108,189, cluster 2), and similar prevalence of breastfeeding and formula feeding with the least exposure to solid foods in infancy (n = 11,811, cluster 3). Compared with cluster 1, children in clusters 2 and 3 had increased risks of all-cause hospitalization (hazard ratio (HR), (95% confidence interval (CI)), 1.04 (1.03-1.06) and 1.08 (1.05-1.11), respectively). Children in clusters 2 and 3 had an increased risk of upper respiratory infection, pneumonia, and gastroenteritis, as well as neurobehavioral diseases. Overweight/obesity at the age of 6 years was associated with clusters 2 and 3. (4) Conclusions: Feeding patterns in infancy were associated with an increased risk of childhood disease burden.

Maternal Pre-Pregnancy BMI, Offspring Adiposity in Late Childhood, and Age of Weaning: A Causal Mediation Analysis

Infant feeding practices have been hypothesized to influence offspring's body mass index (BMI) later in life, and women with overweight or obesity tend to wean their infants earlier than women with healthy BMI. We, therefore, aimed to investigate how much early age of weaning mediated the maternal-offspring adiposity relationship. The study included 4920 mother-child pairs from the Avon Longitudinal Study of Parents and Children birth cohort. G-computation was applied to estimate the natural direct (NDE) and indirect (NIE) effects, via the age of weaning (<3 months, 3 months, >3 months), of maternal pre-pregnancy overweight or obesity on offspring's BMI and fat mass index. The NDE of maternal overweight or obesity on offspring BMI at 17 years old was 2.63 kg/m² (95% CI: 2.27 to 2.99). The NIE via the age of weaning was 0.02 kg/m² (95% CI: 0.00 to 0.04), corresponding to 0.8% of the total effect. Similar results were observed for the offspring's fat mass index. The NDE and NIE were similar to the main analyses when we looked at the relationship stratified by breastfeeding status. Our study found a minimal influence of age of weaning on the pathway between maternal and offspring adiposity, indicating the age of weaning may not be a key mediator.

Evidence for human milk as a biological system and recommendations for study design-a report from "Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN)" Working Group 4

Human milk contains all of the essential nutrients required by the infant within a complex matrix that enhances the bioavailability of many of those nutrients. In addition, human milk is a source of bioactive components, living cells and microbes that facilitate the transition to life outside the womb. Our ability to fully appreciate the importance of this matrix relies on the recognition of short- and long-term health benefits and, as highlighted in previous sections of this supplement, its ecology (i.e., interactions among the lactating parent and breastfed infant as well as within the context of the human milk matrix itself). Designing and interpreting studies to address this complexity depends on the availability of new tools and technologies that account for such complexity. Past efforts have often compared human milk to infant formula, which has provided some insight into the bioactivity of human milk, as a whole, or of individual milk components supplemented with formula. However, this experimental approach cannot capture the contributions of the individual components to the human milk ecology, the interaction between these components within the human milk matrix, or the significance of the matrix itself to enhance human milk bioactivity on outcomes of interest. This paper presents approaches to explore human milk as a biological system and the functional implications of that system and its components. Specifically, we discuss study design and data collection considerations and how emerging analytical technologies, bioinformatics, and systems biology approaches could be applied to advance our understanding of this critical aspect of human biology.

Gestational weight gain and breastfeeding practices in relation to offspring body mass index among Amazonian young children

OBJECTIVE

Excessive weight gain during childhood has been considered an early life risk factor for chronic disease in the long term. We examined the role of excessive gestational weight gain (GWG) and breastfeeding (BF) practices with the offspring's body mass index-for-age z-score (zBMI) at 2 years.

METHODS

Data from 743 Amazonian young children of the MINA-Brazil population-based birth cohort study were used. Linear regression models were run to estimate the associations between excessive GWG and BF practices (exclusive breastfeeding, EBF <3 months of age and BF <1 year) with zBMI.

RESULTS

Excessive GWG and BF <1 year were associated with an adjusted 0.24 units (95% CI: 0.08, 0.41) and 0.28 units (95% CI: 0.12, 0.44) higher zBMI at age 2 years, respectively.

CONCLUSIONS

Gain excessive weight during pregnancy and shorter BF duration (<1y) were associated with a higher body mass index at 2 years of age among Brazilian Amazonian children.

Comparison of the effects of different infant formulas on the growth and development and intestinal flora of infants

The purpose of this study was to compare the effects of different infant formulas on the growth and development, sleep, allergy symptoms, and intestinal flora of infants. A total of 428 infants participated in the study. Breastfeeding (BF) was used as the control, and the remaining subjects were randomly assigned to the full goat milk protein formula group (FGM), partial goat milk protein formula group (PGM), and cow milk formula group (M). During the 6-month feeding experiment, data on the growth, sleep, allergy symptoms, and intestinal flora of infants were collected using questionnaires, anthropometric measurements, and biochemical examinations. In general, the basic information of the participants was consistent among the groups. There were no differences in infant weight, length, or head circumference among the groups (p > .05). The sleep time of infants in the formula-fed groups was longer than that of the breastfeeding group at baseline (p < .05), but there were no differences at mid-term or outcome (p > .05). The incidence of allergic symptoms continued to decrease, and the total scores of allergic symptoms did not differ among the groups (p > .05). The relative abundance of intestinal Bifidobacteriaceae in the PGM group was lower than that in the other groups (p < .05). There was no difference in the β-diversity of intestinal flora between formula-fed and breastfed infants (p > .05). There were strong correlations in the composition of the main intestinal flora at the family level between the formula and breastfeeding groups. This study showed that within 6 months of feeding, there were no significant differences in the growth and development, allergic symptoms, or intestinal flora of the infants among the groups.

The Effects of Breastfeeding for Four Months on Thinness, Overweight, and Obesity in Children Aged 3 to 6 Years: A Retrospective Cohort Study from National Physical Fitness Surveillance of Jiangsu Province, China

Objective: To explore the effects of breastfeeding during the first four months of life on thinness, overweight, and obesity and to analyze the influential factors in children aged three to six years in eastern China. Methods: This study was designed as a retrospective cohort study, and the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines were followed. A total of 8053 subjects were included in this secondary analysis of data from the 2015 “Physical Fitness Surveillance data of Jiangsu, China”. The subjects were classified into three groups on the basis of feeding patterns: breastfeeding, mixed feeding, and formula feeding. The International Obesity Task Force (IOTF) definitions of BMI were used to define thinness, overweight, and obesity. Multivariate logistic regression models and subgroup analysis were used to assess the association between feeding patterns and childhood thinness, overweight, obesity, and overweight/obesity, adjusted for potential confounders (sex, age grade, area, region/economy, gestational age, birthweight, childbearing age, mother’s education, and caretaker). Results: The prevalence of breastfeeding was 63.8%, and the prevalence of thinness, overweight, obesity, and overweight/obesity reached 2.7%, 11.2%, 4.7%, and 15.9%, respectively. Breastfeeding participants had a lower risk of overweight and overweight/obesity with adjusted ORs of 0.652 (95% CI: 0.533, 0.797; p < 0.001) and 0.721 (95% CI: 0.602, 0.862; p < 0.001), respectively; however, there was no difference in thinness and obesity (both p > 0.05) compared with formula feeding. There was no statistical difference between mixed and formula feeding, in terms of thinness, overweight, obesity, or overweight/obesity (all p > 0.05). Subgroup analysis showed that breastfeeding for three years, preterm, and a childbearing age of 25−29 years had higher adjusted ORs for thinness, and in 5−6 years, urban areas, southern/developed economy regions, post-mature, childbearing age ≥ 25 years, and other caretakers had higher and invalid breastfeeding-adjusted ORs (all p > 0.05 except overweight in the urban grade) for both overweight and overweight/obesity. Conclusions: Breastfeeding during the first four months was not associated with the thinness of children aged 3−6 years in eastern China, and the protective effect of breastfeeding against overweight or overweight/obesity could be confirmed. However, the effects of breastfeeding on thinness, overweight, and obesity may change or become invalid in some subgroups, suggesting that there may be potential interactions between feeding patterns and influential factors.

Prolonged breastfeeding protects from obesity by hypothalamic action of hepatic FGF21

Early-life determinants are thought to be a major factor in the rapid increase of obesity. However, while maternal nutrition has been extensively studied, the effects of breastfeeding by the infant on the reprogramming of energy balance in childhood and throughout adulthood remain largely unknown. Here we show that delayed weaning in rat pups protects them against diet-induced obesity in adulthood, through enhanced brown adipose tissue thermogenesis and energy expenditure. In-depth metabolic phenotyping in this rat model as well as in transgenic mice reveals that the effects of prolonged suckling are mediated by increased hepatic fibroblast growth factor 21 (FGF21) production and tanycyte-controlled access to the hypothalamus in adulthood. Specifically, FGF21 activates GABA-containing neurons expressing dopamine receptor 2 in the lateral hypothalamic area and zona incerta. Prolonged breastfeeding thus constitutes a protective mechanism against obesity by affecting long-lasting physiological changes in liver-to-hypothalamus communication and hypothalamic metabolic regulation.

Associations between Breastfeeding Duration and Obesity Phenotypes and the Offsetting Effect of a Healthy Lifestyle

Background: Additional metabolic indicators ought to be combined as outcome variables when exploring the impact of breastfeeding on obesity risk. Given the role of a healthy lifestyle in reducing obesity, we aimed to assess the effect of breastfeeding duration on different obesity phenotypes according to metabolic status in children and adolescents, and to explore the offsetting effect of healthy lifestyle factors on the associations between breastfeeding duration and obesity phenotypes. Methods: A total of 8208 eligible children and adolescents aged 7–18 years were recruited from a Chinese national cross-sectional study conducted in 2013. Anthropometric indicators were measured in the survey sites, metabolic indicators were tested from fasting blood samples, and breastfeeding duration and sociodemographic factors were collected by questionnaires. According to anthropometric and metabolic indicators, obesity phenotypes were divided into metabolic healthy normal weight (MHNW), metabolic unhealthy normal weight (MUNW), metabolic healthy obesity (MHO), and metabolic unhealthy obesity (MUO). Four common obesity risk factors (dietary consumption, physical activity, screen time, and sleep duration) were used to construct a healthy lifestyle score. Scores on the lifestyle index ranged from 0 to 4 and were further divided into unfavorable lifestyles (zero or one healthy lifestyle factor), intermediate lifestyles (two healthy lifestyle factors), and favorable lifestyle (three or four healthy lifestyle factors). Multinomial logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (95% CI) for the associations between breastfeeding duration and obesity phenotypes. Furthermore, the interaction terms of breastfeeding duration and each healthy lifestyle category were tested to explore the offsetting effect of lifestyle factors. Results: The prevalence of obesity among Chinese children and adolescents aged 7–18 years was 11.0%. Among the children and adolescents with obesity, the prevalence of MHO and MUO was 41.0% and 59.0%, respectively. Compared to the children and adolescents who were breastfed for 6–11 months, prolonged breastfeeding (≥12 months) increased the risks of MUNW (OR = 1.35, 95% CI: 1.19–1.52), MHO (OR = 1.61, 95% CI: 1.27–2.05), and MUO (OR = 1.46, 95% CI: 1.20–1.76). When stratified by healthy lifestyle category, there was a typical dose–response relationship between duration of breastfeeding over 12 months and MUNW, MHO, and MUO, with an increased risk of a favorable lifestyle moved to an unfavorable lifestyle. Conclusions: Prolonged breastfeeding (≥12 months) may be associated with increased risks of MUNW, MHO, and MUO, and the benefits of breastfeeding among children and adolescents may begin to wane around the age of 12 months. The increased risks may be largely offset by a favorable lifestyle.

IVF-conceived children outcome from birth to 3 years at a single IVF center in Indonesia: frozen versus fresh embryo transfer

Background

Frozen embryo transfer procedure is becoming more common in assisted reproduction technology. The effect of this technology is still not yet well studied in developing countries with limited resources, including Indonesia. This study explores the clinical outcomes between frozen and fresh embryo transfer-conceived children aged 0–3 years in Indonesia.

Results

The participants were divided into frozen embryo (n = 30) and fresh embryo (n = 30) transfer groups. There were no differences in growth and development. However, in vitro fertilization (IVF) children with frozen embryo transfer had a lower risk of developing low birth weight compared to the fresh embryo group with an OR of 0.17 (95% CI: 0.03–0.85). All children, both in the fresh and frozen embryos, have normal development.

Conclusions

Frozen versus fresh embryo transfer does not affect child growth and development.

Breastfeeding Associations with Childhood Obesity and Body Composition: Findings from a Racially Diverse Maternal-Child Cohort

Background: Studies suggest breastfeeding lowers obesity risk in childhood, but generalizability of existing evidence is limited. We examined associations of breastfeeding with childhood overweight, obesity, and percentage body fat, in a racially diverse maternal-child cohort. Methods: This cross-sectional study included 823 children, ages 4-8 years, enrolled in the Environmental Exposures and Child Health Outcomes (ECHO) cohort, a subset of the National Institute of Child Health and Human Development Fetal Growth Studies cohort. Logistic regression was used to estimate odds ratios and 95% confidence intervals (CIs) for overweight [BMI (kg/m²) 85th to <95th percentile] and obesity (BMI ≥95th percentile) in relation to breastfeeding including duration of exclusive and total breastfeeding. Linear regression was used to evaluate association between breastfeeding and percentage body fat measured by bioelectrical impedance analysis. Results: Fifty-two percent of children were male, 32% non-Hispanic Black, 29% Hispanic, 27% non-Hispanic White, and 13% Asian; 16% were overweight and 13% obese. Six months of exclusive breastfeeding, compared with no breastfeeding, was associated with 60% lower odds of obesity (95% CI 0.18-0.91) adjusting for age, gender, race, socioeconomic status, maternal BMI, and child's activity. Percentage body fat was inversely associated with breastfeeding duration. For none, <6, and ≥6 months of exclusive breastfeeding, adjusted mean percentage body fat was 16.8, 14.5, and 13.4, respectively. Results did not differ by gender, race/ethnicity, or maternal BMI status. Conclusions: Exclusive breastfeeding for the first 6 months of life is inversely and significantly associated with obesity and percentage body fat at ages 4-8 years. These findings support current breastfeeding guidelines.

The impact of neonatal parameters and parental factors on body fat level in early childhood

Parental and pregnancy characteristics can affect proportions and tissue composition of the child's bodyand thereforecan influence their present and future health, as well as overall wellbeing. The aim of this study was to examine the differences between selected parental and birth-related parameters among preschool (3-7 years of age) children of varying adiposity status (n=541 girls and n=571 boys).The research was carried out in 20 randomly selected kindergartens in Krakow (Poland). Thickness of 6 skinfolds (biceps, triceps, subscapular, suprailiac, abdominal and calf) was measured. Sum of skinfolds was calculated and participants were divided into low, normal or high body fat groups. Birth-related characteristics were obtained using a questionnaire filled out by the children's parents. Children of mothers who gained the most gestational weight were characterised by high adiposity. Preschoolers with the highest birth weight, body length and head circumference had the greatest adiposity. Children of relatively younger mothers had higher body fat, in comparison to the rest of the study group. Parents of preschoolers in the high adiposity category were characterised by a greater body mass, compared to the parents of children in other body fat groups and that boys with the highest adiposity relatively more often had a close relative with obesity. Children in varying adiposity categories differed in terms of some birth-related factors. Particular attention should be paid to familial and parental characteristics, because they may influence the child's predisposition to excess adiposity deposition later in life.

Prevalence of Recurrent Hospital Admission in Children with Recurrent Wheezing in Babylon Province

BACKGROUND: Occurring of recurrent wheezing attacks signify a significant healthcare problem and considered one of the most common causes of emergency unit admission and hospitalizations. AIM: The aim of study is to determine the associations of recurrent hospital admissions in children with recurrent wheezing. METHODS: Cross-sectional descriptive study of 102 children with recurrent wheezy chest. Data collected from admitted patients with recurrent wheezing by direct interview with the patients’ families. Patients were 6 months to 5 years old. Data collected including age, gender, place of living whether urban or rural, prematurity, no. of people at home, history of NCU admission, history of ICU admission, exclusive breast feeding for 1st 6 months, anemia, GERD, history of atopy, exposure to smoking, inhaler use, and CXR findings. RESULTS: About 79.41% of children have 1-3 times admission in hospital, significant association between the no. of hospitalization and History of ICU admission, children with more than 3 times admission to hospital present with GERD with significant association. Significant association with more than 3 times admission to hospital have previous history of exposure to smoking, inhaler use and X-ray finding. CONCLUSION: One to three years old children is the most common age they have recurrent wheezing, most children with recurrent wheezy chest have more than 3 times hospitalization, most babies have previous history of ICU admission, GERD and exposure to smoking.

Infant feeding and post-weaning health: Evidence from turn-of-the-century London

Evidence on the post-weaning benefits of early-life breastfeeding is mixed, and highly context-dependent. Moreover, this evidence is drawn almost exclusively from modern settings, limiting our understanding of the relationship between breastfeeding and subsequent health in the past. We provide novel evidence on the nature and reach of these post-weaning benefits in a historical setting, drawing on a rich new longitudinal dataset covering nearly 1000 children from the Foundling Hospital, an orphanage in turn-of-the-century London. We find that even after the cessation of breastfeeding, ever-breastfed status reduced mortality risk and raised weight-for-age in infancy, that exclusive breastfeeding conferred additional benefits, and that breastfeeding duration had little impact. We also find a U-shaped pattern in weight-for-age by time since weaning, indicating a deterioration in health shortly after weaning, followed by a recovery. The early post-weaning advantages associated with breastfeeding, however, did not persist into mid-childhood. This indicates that any protective effects of earlier breastfeeding attenuated with age, and suggests a strong role for catch-up growth. This study contributes to the data and empirical settings available to explore the relationship between infant feeding and post-weaning health, and helps shed light on the contribution of changing breastfeeding norms to trends in health in twentieth-century Britain.

Association of maternal pre-pregnancy BMI and breastfeeding with NAFLD in young adults: a parental negative control study

BACKGROUND

The importance of the maternal-infant dyad in the genesis of nonalcoholic fatty liver disease (NAFLD) is of increasing interest. The Avon Longitudinal Study of Parents and Children (ALSPAC) showed that at age 24, 1 in 5 had NAFLD measured by transient elastography and controlled attenuation parameter (CAP). Our aim was to investigate the association between breastfeeding duration and maternal pre-pregnancy BMI on offspring NAFLD in young adulthood.

METHODS

4021 participants attended clinic for FibroScan and CAP measurement using Echosens 502 Touch®. 440 participants with Alcohol Use Disorders were excluded. Offspring of 100 non-singleton pregnancies were excluded. 2961 valid CAP measurements for NAFLD were analysed. Exposures of interest were breastfeeding of any duration, ≥6months exclusive breastfeeding, and maternal pre-pregnancy BMI. Multivariable regression models estimated the odds of NAFLD at 24 years. We performed a paternal negative control test to explore residual confounding in the analyses of pre-pregnancy BMI.

FINDINGS

There was a modest inverse association of exclusive and non-exclusive breastfeeding ≥6 months having a protective effect on NAFLD in offspring (OR 0·92 [95%CI 0·66-1·27] and OR 0·90 [0·67-1·21] respectively).The odds of offspring NAFLD in overweight pre-pregnancy maternal BMI and paternal BMI was OR 2·09 [1·62-2·68] and OR 1·33 [95%CI 1·07-1·65] respectively, with the ratio of effect sizes OR 1·57 [1·11-2·22]. Similarly, odds of offspring NAFLD with obese pre-pregnancy maternal BMI and paternal BMI was OR 2·66 [1·71-4·14] and OR 1·35 [0·91-2·00] respectively, with the ratio of effect sizes OR 1·98 [1·05-3·74].

INTERPRETATION

Higher maternal pre-pregnancy BMI was associated with offspring NAFLD, having accounted for shared parental confounding. We did not replicate previous work that found a strong association between breastfeeding and NAFLD.

FUNDING

Medical Research Council UK, Alcohol Research UK, David Telling Charitable Trust.

Delivery by caesarean section and offspring adiposity and cardio-metabolic health at ages 6.5, 11.5 and 16 years: results from the PROBIT cohort in Belarus

BACKGROUND

Caesarean delivery has been associated with later adiposity, perhaps via early programming or perhaps because of residual confounding by maternal or birth characteristics.

OBJECTIVES

Examine associations of caesarean delivery with adiposity and cardio-metabolic biomarkers.

METHODS

Observational analysis of 15 069 children in the PROBIT cohort in Belarus. We examined measures of child anthropometry and blood pressure at 6.5, 11.5 and 16 years and fasting blood (11.5 years).

RESULTS

Caesarean-delivered children were slightly heavier at 6.5 (mean BMI 15.8 vs. 15.6 kg/m² ), 11.5 (18.4 vs. 18.2) and 16 years (21.5 vs. 21.3). After adjustment for prenatal characteristics including maternal third trimester BMI, however, we observed no association of caesarean versus vaginal delivery with child BMI (β 0.05 kg/m² ; 95%CI: -0.03, 0.14), sum of skinfolds (0.14 mm; -0.13, 0.42), waist circumference (-0.07 cm; -0.23, 0.10), obesity (OR 0.99; 0.76, 1.29), or systolic (-0.20 mmHg; -0.70, 0.30) or diastolic (-0.17 mmHg, -0.60, 0.26) blood pressure at 6.5 years; results were similar at 11.5 and 16 years. At 11.5 years, we observed a modest association of caesarean delivery with fasting insulin (0.33 mU/L; 0.00, 0.65).

CONCLUSIONS

Caesarean delivery had little or no association with adiposity or related cardio-metabolic biomarkers in childhood. Adjustment for maternal BMI attenuated all outcome effect estimates.

Association of Infant Feeding Methods and Excess Weight from Birth to Age 6

Objective: To examine the associations between human milk feeding method (at the breast versus bottle) and measures of child adiposity during the first 6 years of life. Study Design: Women 12 months' postpartum who delivered a singleton, liveborn infant at >24 weeks gestation completed a survey assessing infant feeding methods and sociodemographics. Mothers were recontacted when the child was 6 years old for a follow-up study assessing growth (N = 269). Children were categorized as ever or never having excess weight using weight-for-age z-scores (WAZ), weight-for-height z-scores (WHZ), and body mass index-for-age z-scores (BMIZ) from birth to 6 years. Modified Poisson regression estimated associations between the duration of each feeding method (exclusive and combined) with excess weight status. Mixed-effect models estimated associations between feeding methods and trajectories of the outcomes. Results: For all feeding practices, increasing duration (in months) was unassociated with the risk of ever having excess weight by age 6 years. Based on mixed models, longer duration of feeding human milk by any method was associated with lower BMIZ (adj β for 6-12 months versus 0-3 months = -0.50, 95% CI: -0.99 to -0.01) and also with the shape of the BMIZ trajectory curve. No other associations between feeding methods and excess weight outcomes were observed. Conclusions: Longer duration of feeding human milk was associated with lower average BMIZ in early childhood but feeding at the breast and feeding expressed milk were not clearly associated with the outcomes when considered separately. Larger studies would help clarify the associations between these specific feeding methods and outcomes. IRB17-00876.

Breastfeeding and Overweight in European Preschoolers: The ToyBox Study

The benefits of breastfeeding (BF) include risk reduction of later overweight and obesity. We aimed to analyse the association between breastfeeding practices and overweight/obesity among preschool children participating in the ToyBox study. Data from children in the six countries, participating in the ToyBox-study (Belgium, Bulgaria, Germany, Greece, Poland, and Spain) 7554 children/families and their age is 3.5–5.5 years, 51.9% were boys collected cross-sectionally in 2012. The questionnaires included parents’ self-reported data on their weight, height, socio-demographic status, and infant feeding practices. Measurements of preschool children’s weight and height were done by trained researchers using standard protocols and equipment. The ever breastfeeding rate in the total sample was 85.0% (n = 5777). Only 6.3% (n = 428) of the children from the general sample were exclusively breastfed (EBF) for the duration of the first six months. EBF for four to six months was significantly (p < 0.001) less likely among mothers with formal education < 12 years (adjusted Odds Ratio (OR) = 0.61; 95% Confidence interval (CI) 0.44–0.85), smoking throughout pregnancy (adjusted OR = 0.39; 95% CI 0.24–0.62), overweight before pregnancy (adjusted OR = 0.67; 95%CI 0.47–0.95) and ≤25 years old. The median duration of any breastfeeding was five months. The prevalence of exclusive formula feeding during the first five months in the general sample was about 12% (n = 830). The prevalence of overweight and obesity at preschool age was 8.0% (n = 542) and 2.8% (n = 190), respectively. The study did not identify any significant association between breastfeeding practices and obesity in childhood when adjusted for relevant confounding factors (p > 0.05). It is likely that sociodemographic and lifestyle factors associated with breastfeeding practices may have an impact on childhood obesity. The identified lower than desirable rates and duration of breastfeeding practices should prompt enhanced efforts for effective promotion, protection, and support of breastfeeding across Europe, and in particular in regions with low BF rates.

Twelve-Month Outcomes of the First 1000 Days Program on Infant Weight Status

OBJECTIVES

To examine the effects of the First 1000 Days intervention on the prevalence of infant overweight and maternal postpartum weight retention and care.

METHODS

Using a quasi-experimental design, we evaluated the effects of the First 1000 Days program among 995 term, low-income infants and their mothers receiving care in 2 intervention community health centers and 650 dyads in 2 comparison health centers. The program includes staff training, growth tracking, health and behavioral screening, patient navigation, text messaging, educational materials, and health coaching. Comparison centers implemented usual care. Infant outcomes were assessed at 6 and 12 months, including weight-for-length z score and overweight (weight for length ≥97.7th percentile). We also examined maternal weight retention and receipt of care 6 weeks' post partum.

RESULTS

The mean birth weight was 3.34 kg (SD 0.45); 57% of infants were Hispanic; 66% were publicly insured. At 6 months, infants had lower weight-for-length z scores (β: -.27; 95% confidence interval [CI]: -.39 to -.15) and lower odds of overweight (adjusted odds ratio [OR]: 0.46; 95% CI: 0.28 to 0.76) than infants in comparison sites; differences persisted at 12 months (z score β: -.18; 95% CI: -.30 to -.07; adjusted OR for overweight: 0.60; 95% CI: 0.39 to 0.92). Mothers in the intervention sites had modestly lower, but nonsignificant, weight retention at 6 weeks' post partum (β: -.51 kg; 95% CI: -1.15 to .13) and had higher odds (adjusted OR: 1.50; 95% CI: 1.16 to 1.94) of completing their postpartum visit compared with mothers in the comparison sites.

CONCLUSIONS

An early-life systems-change intervention combined with coaching was associated with improved infant weight status and maternal postpartum care.

Type 2 diabetes in pediatrics

Type 2 diabetes (T2D) in adolescents has become an increasing health concern throughout the world and its prevention and screening should be implemented in pediatric care. As clinical features at presentation, in some cases can be similar to type 1 diabetes and family history can be in favour of a monogenic form of diabetes, it is pivotal for physicians to be aware of youth-onset T2D specificities to ensure an accurate diagnosis. The global increase of overweight and obesity can complicate the diagnostic process and makes it essential to apply a systematic approach to each new diagnosis. Microvascular complications may be present at the time of diagnosis and chronic complications are frequent and need to be screened regularly. Regular screening of comorbidities should also be performed. Childhood T2D should be followed up by pediatric diabetes units to avoid diagnostic errors and delay in care. A multidisciplinary approach, by an experienced team, is pivotal to provide treatment options targeting the unique needs of pediatric patients. Treatment programs must include the whole family and address all the aspects of the care (lifestyle, pharmacological therapy, psychological aspects, complications and comorbidities). An organized process of transition to adult care is essential.

Examining supports and barriers to breastfeeding through a socio-ecological lens: a qualitative study

BACKGROUND

Early breastfeeding cessation is a societal concern given its importance to the health of mother and child. More effective interventions are needed to increase breastfeeding duration. Prior to developing such interventions more research is needed to examine breastfeeding supports and barriers from the perspective of breastfeeding stakeholders. One such framework that can be utilized is the Socio-Ecological Model which stems from Urie Broffenbrenner's early theoretical frameworks (1973-1979). The purpose of this study was to examine supports and barriers to breastfeeding across environmental systems.

METHODS

A total of 49 representatives participated in a telephone interview in Nebraska, USA in 2019. Interviewees represented various levels of the model, based on their current breastfeeding experience (i.e., mother or significant other) or occupation. A direct content analysis was performed as well as a constant comparative analysis to determine differences between level representatives.

RESULTS

At the Individual level, breastfeeding is a valued behavior, however, women are hindered by exhaustion, isolation, and the time commitment of breastfeeding. At the Interpersonal level, social media, peer-to-peer, and family were identified as supports for breastfeeding, however lack of familial support was also identified as a barrier. At the community level, participants were split between identifying cultural acceptance of breastfeeding as support or barrier. At the organizational level, hospitals had supportive breastfeeding friendly policies in place however lacked enough personnel with breastfeeding expertise. At the policy level, breastfeeding legislation is supportive, however, more specific breastfeeding legislation is needed to ensure workplace breastfeeding protections.

CONCLUSION

Future efforts should target hospital-community partnerships, family-centered education, evidence-based social media strategies and improved breastfeeding legislation to ensure breastfeeding women receive effective support throughout their breastfeeding journey.

Breastfeeding and risk of overweight in childhood and beyond: a systematic review with emphasis on sibling-pair and intervention studies

BACKGROUND

Breastfeeding is associated with a lower risk of subsequent overweight or obesity, but it is uncertain whether this is a causal relation because most studies have not adequately reduced risk of bias due to confounding.

OBJECTIVES

The aim of this review was to examine whether 1) ever compared with never consuming human milk and 2) different durations of human milk consumption among infants fed human milk are related to later risk of overweight or obesity, with emphasis on sibling-pair and intervention studies.

METHODS

The 2020 Dietary Guidelines Advisory Committee, together with the Nutrition Evidence Systematic Review team, conducted a systematic review of articles relevant to healthy full-term infants in countries with a high or very high level of human development. We searched PubMed, Embase, Cochrane, and CINAHL; dual-screened the results using predetermined criteria; extracted data from and assessed the risk of bias for each included study; qualitatively synthesized the evidence; developed conclusion statements; and graded the strength of the evidence.

RESULTS

The review included 42 articles, including 6 cohorts with sibling-pair analyses and 1 randomized controlled trial of a breastfeeding promotion intervention. Moderate evidence suggested that ever, compared with never, consuming human milk is associated with a lower risk of overweight and obesity at ages 2 y and older, particularly if the duration of human milk consumption is >6 mo. However, residual confounding cannot be ruled out. Evidence was insufficient to determine the relation between the duration of any human milk consumption, among infants fed human milk, and overweight and/or obesity at age 2 y and older.

CONCLUSIONS

Further research, using strong study designs, is needed to disentangle the complex relation between infant feeding practices and the risk of subsequent overweight or obesity, as well as the biological and behavioral mechanisms if the relation is causal.

Nutritional Strategies for Childhood Obesity Prevention

BACKGROUND

Reducing the spread of obesity represents a challenge for clinicians in which obesity prevention plays a key role in achieving this purpose. The aim of this review is to analyze the nutritional interventions that can be implemented to prevent childhood obesity.

METHODS

Searching PubMed and Cochrane Library between 2019 and 2021. Further searching with no date range for articles selected for their specific relevance in the pediatric area or for their scientific relevance. A total of 871 articles were identified and 90 were included.

RESULTS

We organized the results of the selected articles into age groups, and according to the subjects targeted for interventions or to the site of interventions, reserving an in-depth analysis on specific nutritional aspects. Promotion of breastfeeding, reduction of protein content of formulated milks, and diet of the first 12-24 months, involving family and schools in interventions that promote physical activity and healthy diet, are promising strategies for reduction of the risk of obesity. To increase the efficacy of interventions, a multidimensional approach is crucial.

CONCLUSIONS

A multidimensional approach, which takes into consideration different areas of intervention, is pivotal for childhood obesity prevention. Integrated programs involving several components (nutrition and physical activity at first) at different levels (individual, family, school, and institutional) are crucial.

A mixed methods study of perinatal sleep and breastfeeding outcomes in women at risk for postpartum depression

INTRODUCTION

Pregnant and postpartum women experience significant sleep disruption, but the role of perinatal sleep disturbances in breastfeeding is understudied.

METHODS

In this observational cohort study, we used mixed methods to examine associations between perinatal sleep and breastfeeding. Forty-eight women (mean age 28.2 ± 4.9 years) who were euthymic at enrollment but had a history of major depression (n = 43) or bipolar disorder (n = 5) had sleep recorded with wrist actigraphy. We determined feeding status through daily diaries and used semi-structured interviews to identify themes regarding participants' experiences, breastfeeding decisions, and behaviors. To examine whether sleep disturbance during pregnancy predicted breastfeeding (BF) rates, we defined "lower sleep efficiency" (LSE) and "higher sleep efficiency" (HSE) groups based on the median split of actigraphic SE at 33 weeks' gestation (cutoff SE = 84.9%) and classified mothers as No-BF, Mixed-BF (BF + formula), and Exclusive-BF at 2 weeks postpartum.

RESULTS

Percentages of women who did any breastfeeding were: Week 2 = 72.3%, Week 6 = 62.5%, Week 16 = 50%. LSE mothers were less likely than HSE mothers to initiate breastfeeding (percent No-BF: LSE = 45.8%, HSE = 16.7%, P < .05). Average actigraphic sleep onset, sleep offset, time in bed, sleep duration, and SE did not differ based on breastfeeding status at any time point. Qualitative themes included insufficient preparation for the demands of breastfeeding, interrupted and nonrestorative sleep, and unrelenting daytime tiredness.

CONCLUSIONS

In our sample, preserved actigraphic SE during pregnancy was associated with initiation and continuation of breastfeeding. Future work should examine whether improving sleep in pregnancy improves mothers' feeding experiences.

Interactions between Growth of Muscle and Stature: Mechanisms Involved and Their Nutritional Sensitivity to Dietary Protein: The Protein-Stat Revisited

Childhood growth and its sensitivity to dietary protein is reviewed within a Protein-Stat model of growth regulation. The coordination of growth of muscle and stature is a combination of genetic programming, and of two-way mechanical interactions involving the mechanotransduction of muscle growth through stretching by bone length growth, the core Protein-Stat feature, and the strengthening of bone through muscle contraction via the mechanostat. Thus, growth in bone length is the initiating event and this is always observed. Endocrine and cellular mechanisms of growth in stature are reviewed in terms of the growth hormone-insulin like growth factor-1 (GH-IGF-1) and thyroid axes and the sex hormones, which together mediate endochondral ossification in the growth plate and bone lengthening. Cellular mechanisms of muscle growth during development are then reviewed identifying (a) the difficulties posed by the need to maintain its ultrastructure during myofibre hypertrophy within the extracellular matrix and the concept of muscle as concentric "bags" allowing growth to be conceived as bag enlargement and filling, (b) the cellular and molecular mechanisms involved in the mechanotransduction of satellite and mesenchymal stromal cells, to enable both connective tissue remodelling and provision of new myonuclei to aid myofibre hypertrophy and (c) the implications of myofibre hypertrophy for protein turnover within the myonuclear domain. Experimental data from rodent and avian animal models illustrate likely changes in DNA domain size and protein turnover during developmental and stretch-induced muscle growth and between different muscle fibre types. Growth of muscle in male rats during adulthood suggests that "bag enlargement" is achieved mainly through the action of mesenchymal stromal cells. Current understanding of the nutritional regulation of protein deposition in muscle, deriving from experimental studies in animals and human adults, is reviewed, identifying regulation by amino acids, insulin and myofibre volume changes acting to increase both ribosomal capacity and efficiency of muscle protein synthesis via the mechanistic target of rapamycin complex 1 (mTORC1) and the phenomenon of a "bag-full" inhibitory signal has been identified in human skeletal muscle. The final section deals with the nutritional sensitivity of growth of muscle and stature to dietary protein in children. Growth in length/height as a function of dietary protein intake is described in the context of the breastfed child as the normative growth model, and the "Early Protein Hypothesis" linking high protein intakes in infancy to later adiposity. The extensive paediatric studies on serum IGF-1 and child growth are reviewed but their clinical relevance is of limited value for understanding growth regulation; a role in energy metabolism and homeostasis, acting with insulin to mediate adiposity, is probably more important. Information on the influence of dietary protein on muscle mass per se as opposed to lean body mass is limited but suggests that increased protein intake in children is unable to promote muscle growth in excess of that linked to genotypic growth in length/height. One possible exception is milk protein intake, which cohort and cross-cultural studies suggest can increase height and associated muscle growth, although such effects have yet to be demonstrated by randomised controlled trials.

Overweight in childhood of exclusively breastfed infants with a high weight at 5 months

High infant weight increases the risk of childhood overweight, while breastfeeding may reduce the risk. However, some infants have a very high weight gain even though they are exclusively breastfed. We examined the risk of a high body mass index (BMI) and overweight in childhood for infants ≥2.5 SD above the median weight-for-age (WAZ) at age 5 months according to duration of exclusive breastfeeding (≤2, >2 to <4 or ≥4 months). The study is based on 13,401 7-year-old and 9,819 11-year-old children enrolled into the Danish National Birth Cohort (born 1997-2003). Linear and logistic regression analyses were used to examine the associations while adjusting for presumed confounders including birth weight. The results showed that infants ≥2.5 SD at 5 months, breastfed exclusively ≤2, >2 to <4 or ≥4 months had adjusted odds ratios (ORs) for overweight at age 7 at 3.67 (95% confidence interval [CI] [2.10, 6.43]), 3.42 (95% CI [2.32, 5.04]) and 3.19 (95% CI [1.90, 5.36]) respectively, when compared with infants <2.5 SD WAZ exclusively breastfed ≥4 months. The corresponding results for BMI z-scores were 0.82 (95% CI [0.60, 1.04]), 0.63 (95% CI [0.48, 0.78]) and 0.57 (95% CI [0.38, 0.77]). For the ≥2.5 SD infants, the differences in risk of overweight and BMI according to duration of exclusive breastfeeding were neither significantly different among the 7-year nor among the 11-year-old children. A high infant weight increases the odds of overweight and is associated with a higher BMI in childhood. Whereas the odds and BMI z-scores tended to be lower for those exclusively breastfed longer, the differences were not statistically significant.

Associations between human milk oligosaccharides (HMOs) and eating behaviour in Hispanic infants at 1 and 6 months of age

BACKGROUND

Human milk oligosaccharides (HMOs) are naturally occurring glycans in human breast milk that act as prebiotics in the infant gut. Prebiotics have been demonstrated to suppress appetite in both adults and children. Therefore, HMOs may affect infant eating behaviour.

OBJECTIVE

To determine if HMOs in breast milk are associated with eating behaviour in Hispanic infants.

METHODS

Cross-sectional analysis of a prospective cohort of Hispanic mother-infant dyads (1-month, n = 157; 6-months, n = 69). Breast milk samples were screened for 19 HMOs using high pressure liquid chromatography, and eating behaviour was assessed using the Baby Eating Behaviour Questionnaire (BEBQ). We conducted multiple linear regressions to examine associations between HMOs and BEBQ scores, adjusted for maternal pre-pregnancy BMI, infant sex, birthweight, delivery mode and number of breastfeedings per day. We stratified by HMO secretor status-a genetic determinant of the types of HMOs produced.

RESULTS

At 1 month, LNnT (lacto-N-neotetraose; P = .04) was negatively associated with food responsiveness in the total sample, while DFLNT (difucosyllacto-N-tetrose; P = .03) and DSLNT (disialyl-LNT; P = .04) were negatively associated with food responsiveness in secretors only. At 6 months, LSTc (sialyllacto-N-tetraose c; P = .01), FLNH (fucosyllacto-N-hexaose; P = .03), LNH (lacto-N-hexaose; P = .006) and DSLNH (disialyllacto-N-hexaose; P = .05) were positively associated with food responsiveness in both the total sample and secretors only.

CONCLUSIONS

We found several HMOs that were both positively and negatively associated with infant food responsiveness, which is a measure of drive to eat.

Long-Term Follow-Up of a Randomized Controlled Trial to Reduce Excessive Weight Gain in Infancy: Protocol for the Prevention of Overweight in Infancy (POI) Follow-Up Study at 11 Years

Background

The Prevention of Overweight in Infancy (POI) randomized controlled trial assessed the effect of a more conventional food, physical activity, and breastfeeding intervention, with a more novel sleep intervention on weight outcomes at 2 years of age. The trial had 58% uptake at recruitment, and retention was 86% at age 2 years, 77% at age 3.5 years, and 69% at age 5 years. Children who received the brief sleep intervention in infancy had just half the risk of obesity at 2 years of age compared to those who did not receive the sleep intervention. Importantly, this substantially reduced risk was still apparent at our follow-up at 5 years of age.

Objective

The primary aim of this follow-up at age 11 years is to determine whether differences in BMI z-score and obesity risk remain apparent now that it is at least 9 years since cessation of the sleep intervention. Several secondary outcomes of interest will also be examined including 24-hour movement patterns, mental health and wellbeing, and use of electronic media, particularly prior to sleep.

Methods

We will seek renewed consent from all 734 of the original 802 POI families who expressed interest in further involvement. Children and parent(s) will attend 2 clinics and 1 home appointment to obtain measures of anthropometry and body composition (dual-energy x-ray absorptiometry scan), 24-hour movement patterns (sleep, sedentary time, and physical activity measured using an AX3 accelerometer), mental health and wellbeing (validated questionnaires), family functioning (validated questionnaires), use of electronic media (wearable and stationary cameras, questionnaires), and diet and eating behaviors (24-hour recall, questionnaires).

Results

This follow-up study has full ethical approval from the University of Otago Human Ethics Committee (H19/109) and was funded in May 2019 by the Health Research Council of New Zealand (grant 19/346). Data collection commenced in June 2020, and first results are expected to be submitted for publication in 2022.

Conclusions

Long-term outcomes of early obesity intervention are rare. Despite the growing body of evidence linking insufficient sleep with an increased risk of obesity in children, interventions targeting improvements in sleep have been insufficiently explored. Our initial follow-up at 5 years of age suggested that an early sleep intervention may have long-term benefits for effective weight management in children. Further analysis in our now preteen population will provide much-needed evidence regarding the long-term effectiveness of sleep interventions in infancy as an obesity prevention approach.

Trial Registration

ClinicalTrials.gov NCT00892983; https://tinyurl.com/y3xepvxf

International Registered Report Identifier (IRRID)

DERR1-10.2196/24968

Early Determinants of Childhood Blood Pressure at the Age of 6 Years: The GECKO Drenthe and ABCD Study Birth Cohorts

Background

There is still uncertainty about the nature and relative impact of early determinants on childhood blood pressure. This study explored determinants of blood pressure at the age of 6 years in 2 Dutch birth cohorts.

Methods and Results

Results of hierarchical multiple linear regression analyses in GECKO (Groningen Expert Center for Kids With Obesity) Drenthe study (n=1613) were replicated in ABCD (Amsterdam Born Children and Their Development) study (n=2052). All analyses were adjusted for child's age, sex, height, and body mass index (BMI), and maternal education and subsequently performed in the combined sample. No associations were found between maternal smoking during pregnancy and childhood blood pressure. In the total sample, maternal prepregnancy BMI was positively associated with systolic blood pressure (SBP) (β [95% CI], 0.09 [0.02–0.16] mm Hg) and diastolic blood pressure (β [95% CI], 0.11 [0.04–0.17] mm Hg). Children of women with hypertension had higher SBP (β [95% CI], 0.98 [0.17–1.79] mm Hg). Birth weight standardized for gestational age was inversely associated with SBP (β [95% CI], −6.93 [−9.25 to −4.61] mm Hg) and diastolic blood pressure (β [95% CI], −3.65 [−5.70 to −1.61] mm Hg). Longer gestational age was associated with lower SBP (β [95% CI] per week, −0.25 [−0.42 to −0.08] mm Hg). Breastfeeding for 1 to 3 months was associated with lower SBP (β [95% CI], −0.96 [−1.82 to −0.09] mm Hg) compared with no or <1 month of breastfeeding. Early BMI gain from the age of 2 to 6 years was positively associated with SBP (β [95% CI], 0.41 [0.08–0.74] mm Hg) and diastolic blood pressure (β [95% CI], 0.37 [0.07–0.66] mm Hg), but no effect modification by birth weight was found.

Conclusions

Higher maternal prepregnancy BMI, maternal hypertension, a relatively lower birth weight for gestational age, shorter gestational age, limited duration of breastfeeding, and more rapid early BMI gain contribute to higher childhood blood pressure at the age of 6 years.

Nutrition- and feeding practice-related risk factors for rapid weight gain during the first year of life: a population-based birth cohort study

Background

Rapid weight gain (RWG) during infancy increases the risk of excess weight later in life. Nutrition- and feeding practices associated with RWG need to be further examined. The present study aimed to examine nutrition- and feeding practice-related risk factors for RWG during the first year of life.

Methods

A population-based longitudinal birth cohort study of 1780 infants, classified as having RWG or non-RWG during 0–3-4, 0–6 and 6–12 months. RWG was defined as a change > 0.67 in weight standard deviation scores. Associations between nutrition- and feeding practice-related factors and RWG were examined with logistic regression models.

Results

Of the participating infants, 47% had RWG during 0–3-4 months, 46% during 0–6 months and 8% during 6–12 months. In the fully adjusted models, bottle-feeding at birth and at 3–4 months and nighttime meals containing formula milk were positively associated with RWG during 0–3-4 months (p < 0.05 for all). Breastfeeding at 3–4 months and nighttime meals containing breast milk were negatively associated with RWG during this period (p < 0.001). Bottle-feeding at birth, 3–4 and 6 months and nighttime meals containing formula milk at 3–4 months were positively associated with RWG during 0–6 months (p < 0.01 for all). Breastfeeding at 3–4 and 6 months was negatively associated with RWG (p < 0.01). During 6–12 months, only bottle-feeding at 3–4 months was positively associated with RWG (p < 0.05).

Conclusions

RWG was more common during the first 6 months of life and bottle-feeding and formula milk given at night were risk factors for RWG during this period.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12887-020-02391-4.

Mixed milk feeding: a systematic review and meta-analysis of its prevalence and drivers

CONTEXT

Extensive literature is available on exclusive breastfeeding and formula-feeding practices and health effects. In contrast, limited and unstructured literature exists on mixed milk feeding (MMF), here defined as the combination of breastfeeding and formula feeding during the same period in term infants > 72 hours old (inclusion criterion).

OBJECTIVE

A systematic review and meta-analysis were performed, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, on the global prevalence of MMF (primary outcome) and related drivers and practices (secondary outcomes).

DATA SOURCES

The search of MMF in generally healthy populations was conducted across 6 databases, restricted to publications from January 2000 to August 2018 in English, Spanish, French, and Mandarin.

DATA EXTRACTION

Two reviewers independently performed screenings and data extraction according to a priori inclusion and exclusion criteria.

DATA ANALYSIS

Of the 2931 abstracts identified, 151 full-text publications were included for data extraction and 96 of those were included for data synthesis (the majority of those were cross-sectional and cohort studies). The authors summarized data across 5 different categories (feeding intention prenatally, and 4 age intervals between > 72 hours and > 6-23 months) and 5 regional subgroups. The overall prevalence of MMF across different age intervals and regions varied between 23% and 32%; the highest rate was found for the age group 4-6 months (32%; 95% confidence interval, 27%-38%); regional comparisons indicated highest MMF rates in Asia (34%), North and South America (33%), and Middle East and Africa together (36%), using a random effects meta-analysis model for proportions. Some drivers and practices for MMF were identified.

CONCLUSION

MMF is a widespread feeding reality. A shared and aligned definition of MMF will help shed light on this feeding practice and evaluate its influence on the duration of total breastfeeding, as well as on infants' nutrition status, growth, development, and health status in the short and long terms. PROSPERO registration number CRD42018105337.

Early-Life Nutrition Interventions and Associated Long-Term Cardiometabolic Outcomes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Early-life nutrition interventions can have lifelong cardiometabolic benefits. Most evidence on this topic is derived from observational studies. We evaluated the association of randomized controlled nutritional trials in early life and long-term cardiometabolic outcomes. Through literature search of PubMed, CABI Global Health, Embase, and Cochrane, with manual reference check and weekly alert from PubMed, we identified 8312 records, and included 53 records from 40 cohorts in 21 countries. The total number of participants was 33,551. Interventions were initiated as early as conception, and the longest until 7 y (except 1 study from infancy to 20 y). The cohorts were followed up for between 3 and 73 y. We identified 7 types of interventions (protein-energy supplements, long-chain PUFAs, single micronutrient, multiple micronutrients, infant and young child feeding, dietary counseling, and other) and 4 categories of cardiometabolic outcomes (biomarkers, cardiovascular, body size and composition, and subclinical/clinical outcomes). Most findings were null. Fasting glucose concentration was 0.04 mmol/L lower (95% CI: -0.05, -0.02 mmol/L; I2 = 0%) in the intervention groups than in the control groups (15 studies). BMI (kg/m2) was 0.20 higher (95% CI: 0.12, 0.28; I2 = 54%) in the intervention groups than control groups (14 studies). No significant effect was observed for total cholesterol (12 studies) or blood pressure (17 studies). Ongoing and personalized dietary counseling was associated with lower glucose and cholesterol, better endothelial function, and reduced risk of metabolic syndrome. The timing of intervention mattered, with earlier initiation conferring greater benefit (improved lipid profile and marginally lower glucose concentration) based on 2 studies. In sum, glucose concentration was lower following early-life nutrition interventions, but there is a risk of unintended consequences, including higher BMI. Maternal and child nutrition interventions must be evidence-based and tailored to each population to promote long-term cardiometabolic health.

Human milk composition differs by maternal BMI in the first 9 months postpartum

BACKGROUND

Studies indicate that maternal weight status modulates human milk composition; however, results are conflicting.

OBJECTIVES

Our objective was to examine the relation between maternal body composition and human milk macronutrients and bioactive components and also their association with infant daily intakes and body composition.

METHODS

Human milk samples were obtained from a longitudinal study (NCT01131117) in normal weight (NW: 18.5-24.9 kg/m2, n = 88) and overweight/obese (OW: 25-35 kg/m2, n = 86) women between 0.5 and 9 mo postpartum. Macronutrient content was estimated using mid-infrared spectroscopy. Leptin, insulin, and C-reactive protein (CRP) were measured using electrochemiluminescence immunoassays. Infant body composition was obtained using quantitative MRI. Linear mixed models were adjusted for postpartum age and infant sex.

RESULTS

Human milk in OW mothers was higher in fat and protein and lower in carbohydrate content at some time points compared with that in NW mothers. Human milk leptin, insulin, and CRP concentrations were higher in OW mothers compared with NW mothers, with infants of OW mothers exposed to 1.5-2.5 times higher concentrations of leptin and insulin compared with infants of NW mothers. Similar results were observed when concentrations were normalized to infant daily intake and body weight. The effect sizes of infant daily intakes associated with infant growth parameters were small for macronutrients [0.005-0.05 z-score units and 0.02-0.45 fat mass index (FMI) or fat-free mass index units per unit of change in composition, P < 0.05]. Larger effect sizes were seen with human milk insulin and leptin (0.24 z-score units and 0.37-1.15 FMI units per unit of change in composition, P < 0.05).

CONCLUSIONS

These findings demonstrate that infants of OW mothers are exposed to higher concentrations of insulin, leptin, and, to a lesser extent, CRP. The bioavailability of these 3 human milk bioactives and their mechanisms of action in the infant are unclear.This trial was registered at clinicaltrials.gov as NCT01131117.

Interaction effects of significant risk factors on overweight or obesity among 7222 preschool-aged children from Beijing

OBJECTIVES

We aimed to identify potential risk factors, both individually and interactively, associated with overweight and obesity among preschool-aged children, and further to create a risk prediction nomogram model.

RESULTS

After graded multivariable adjustment, maternal body mass index (BMI) (odds ratio, 95% confidence interval, P under China criteria: 1.07, 1.05 to 1.10, <0.001), maternal pre-pregnancy BMI (1.08, 1.05 to 1.10, <0.001), breastfeeding duration (0.86, 0.76 to 0.98, 0.019), and sleep duration (0.95, 0.90 to 1.00, 0.042) were found to be independently and consistently associated with the significant risk of childhood overweight or obesity under three different growth criteria. Further analyses revealed the four significant factors acted in an additive manner, especially for the interaction between maternal obesity, sleep duration, and breastfeeding. Finally, a risk prediction nomogram model was created for childhood overweight or obesity based on significant and conventional attributes under each criterion.

CONCLUSIONS

Our findings provide evidence that the four significant factors are associated with the risk of childhood overweight or obesity in an additive manner.

METHODS

Using a stratified cluster random sampling strategy, 7222 preschool-aged children were analyzed. Childhood overweight and obesity are defined according to the China criteria and two widely-used international growth criteria.

Maternal psychological distress and child weight at 24 months: investigating indirect effects through breastfeeding in the All Our Families cohort

OBJECTIVE

Maternal psychological distress in pregnancy has been associated with both breastfeeding duration and child weight at 24 months; however, the potential that breastfeeding duration partially mediates the risk of maternal mental health problems during pregnancy on child weight classification has not been examined. The current study investigated this proposed relationship.

METHODS

Data was taken from the All Our Families (AOF) cohort, an ongoing prospective pregnancy cohort located in Calgary, Canada. Psychological distress, defined as clinically significant symptoms of anxiety and depression, was assessed via self-report and measured between 34 and 36 weeks of gestation. Breastfeeding duration was assessed in the postpartum by self-report. Child overweight classification was defined as a weight-for-length/height z-score at or above the 97th percentile as per World Health Organization's child growth guidelines.

RESULTS

In this sample of 1582 mother-child pairs, there was no direct relationship between psychological distress and child overweight status. Both anxiety (B = - 5.40, p = 0.001) and depression (B = - 6.54, p = 0.008) were associated with decreased weeks breastfeeding. Breastfeeding duration mediated the association between maternal prenatal psychological distress and child overweight status at 24 months, for both anxiety (B(SE) = 0.10(0.05), CI 0.03-0.21) and depression (B(SE) = 0.11(0.07), CI 0.01-0.27). Covariates included maternal age, education, ethnicity, income, pre-pregnancy BMI, gestational weight gain, and infant birth weight.

CONCLUSIONS

The results of this longitudinal cohort analysis support an indirect relationship between maternal psychological distress in pregnancy and the childhood overweight/obesity at 24 months old, mediated through breastfeeding duration.

Growth patterns from birth to overweight at age 5-6 years of children with various backgrounds in socioeconomic status and country of origin: the ABCD study

INTRODUCTION

Children from minority groups are at increased risk of overweight. This study compared BMI growth patterns from birth onwards of boys and girls with overweight at 5-6 years, according to socioeconomic status (SES) and country of origin, in order to gain more insight into the critical periods of growth to overweight.

METHODS

A total of 3714 singletons of the multi-ethnic ABCD study were included. Within children with overweight at age 5-6 years (N = 487, prevalence boys: 11.6%, girls: 14.6%), BMI growth patterns from birth onwards (12.8 serial measurements; SD = 3.1) were compared between children from European (69.4%) and non-European mothers (30.6%), and between children from low (20.8%), mid (37.0%) or high SES (42.2%), based on maternal educational level.

RESULTS

BMI growth to overweight did not differ between children of European or non-European mothers, but it did differ according to maternal SES. Children with overweight in the low and mid SES group had a lower BMI in the first 2 years of life, an earlier adiposity rebound and increased in BMI more rapidly after age 2, resulting in a higher BMI at age 7 years compared to children with overweight in the high SES group [∆BMI (kg/m2 ) between high and low SES: boys 1.43(95%CI:0.16;3.01) and girls 1.91(0.55;3.27)].

CONCLUSION

Children with overweight from low SES have an early adiposity rebound and accelerated growth to a higher BMI at age 5-6 years compared to children with overweight from the high SES group. These results imply that timing of critical periods for overweight development is earlier in children with a low socioeconomic background as compared to other children.

Metabolomic Insights into the Effects of Breast Milk Versus Formula Milk Feeding in Infants

PURPOSE OF REVIEW

This review summarizes the latest scientific evidence for the presence of metabolomic differences between infants fed breast milk (I-BM) and infants fed formula milk (I-FM).

RECENT FINDINGS

Across the studies included in this review, a total of 261 metabolites were analyzed, of which 151 metabolites were reported as significantly associated with infant feeding modality (BM versus FM). However, taken as a whole, the relevant literature was notable both for methodological limitations, such as small sample sizes, and heterogeneity between the studies. This may be why many associations between infant metabolite profile and feeding modality have not replicated across studies. To our knowledge, this is the first review to integrate the available literature on metabolomic differences between I-BM versus I-FM. This narrative review synthesized the data across studies and identified those metabolites which show the most robust associations with infant feeding modality. Methodological limitations of the current studies are identified, followed by recommendations for how to address these in future studies.

A Meta-Analysis of the Association Between Breastfeeding and Early Childhood Obesity

PROBLEM

Several studies have indicated a protective effect of breastfeeding on reducing the risk of childhood obesity, however, this remains controversial. The aim of this meta-analysis is to clarify the association between breastfeeding and the risk of preschoolers' obesity.

ELIGIBILITY CRITERIA

Prospective cohort studies published prior to December 1, 2019 were systematically searched in PubMed, EMBASE, the Web of Science and the Cochrane Library databases. Meta-analysis was performed using Stata 15.1.

SAMPLE

Twenty-six publications involving 332,297 participants were eligible for inclusion.

RESULTS

The pooled odds ratio (OR) of the risk of obesity in ever-breastfed preschoolers was 0.83 (95%CI [0.73,0.94]) compared with their never-breastfed counterparts. Random-effects dose-response model revealed a negative correlation between the duration of breastfeeding and risk of obesity (regression coefficient = -0.032, p = .001). Categorical analysis confirmed this dose-response association (1 day to <3 months of breastfeeding: OR = 1.07, 95%CI [0.94,1.21]; 3 months to <6 months: OR = 0.96, 95%CI [0.60,1.54]; ≥6 months: OR = 0.67, 95%CI [0.58,0.77]). One month of breastfeeding was associated with a 4.0% decrease in risk of obesity (OR = 0.96/month of breastfeeding, 95% CI [0.95, 0.97]). Under the reference of never breastfeeding, the summary OR of exclusive breastfeeding was 0.53 (95%CI [0.45,0.63]).

CONCLUSIONS

Breastfeeding is inversely associated with a risk of early obesity in children aged two to six years. Moreover, there is a dose-response effect between duration of breastfeeding and reduced risk of early childhood obesity.

IMPLICATIONS

Clinical nurses' guidance and advice that prolong the duration of breastfeeding and promote exclusive breastfeeding are needed to prevent the development of later childhood obesity.

Every month matters: longitudinal associations between exclusive breastfeeding duration, child growth and obesity among WIC-participating children

BACKGROUND

Research has found breastfeeding to be protective of obesity; however, this link remains contentious. We examined longitudinal associations between exclusive breastfeeding duration, growth trajectories and obesity at 4 years among children participating in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC), and whether these associations differed in the context of the 2009 WIC food package change, implemented to improve alignment with dietary guidelines and promote breastfeeding.

METHODS

Longitudinal data from 260 935 WIC-participating children in Los Angeles County, California, 2003-2016, were used to assess the relationship between duration of receipt of the fully breastfeeding package (an exclusive breastfeeding proxy) with childhood growth and obesity using mixed effects and Poisson regression models.

RESULTS

Children exclusively breastfed for longer duration had healthier growth trajectories and lower obesity risk at age 4. Compared with infants with no fully breastfeeding package receipt, any receipt (a breastfeeding initiation proxy) was associated with reduced obesity risk. Obesity risk was lowest for boys and girls exclusively breastfed for 7 (risk ratio (RR)=0.73, 95% CI=0.64 to 0.82) and 13 months (RR=0.63, 95% CI=0.58 to 0.69), respectively. Exclusive breastfeeding duration increased, but associations between exclusive breastfeeding duration and growth and obesity were not modified, following the 2009 WIC food package change.

CONCLUSION

Increased duration of exclusive breastfeeding was associated with reduced obesity risk. The greatest incremental benefit was observed going from none to any exclusive breastfeeding, and the maximum cumulative benefit was among children receiving the fully breastfeeding package for more than 6 months. Breastfeeding promotion in WIC remains important for obesity prevention.