Parental Reports of Infant and Child Eating Behaviors are not Affected by Their Beliefs About Their Twins' Zygosity

Birth weight, slowness in eating and feeding practices as independent determinants of rapid weight gain

AIM

Our aim was to identify independent determinants of rapid weight gain in infants at 3-4, 6, and 12 months of age.

METHODS

A cohort study was conducted on Mexican term infants in public and private settings between March 2021 and May 2023. Rapid weight gain was defined as a ≥0.67 SD change in weight-for-age-Z-score from birth to 3-4, 6, and 12 months of age. Maternal and infant characteristics were described, and infant feeding practices, appetitive traits, weight, and length were analysed at 3-4, 6, and 12 months of age. Rapid weight gain predictors were determined using generalised linear regression models.

RESULTS

In total, 168 infants were recruited (55% boys). Small-for-gestational-age status increased rapid weight gain risk 1.5 times, whereas large-for-gestational-age status represented a 20%-30% decrease. Slowness in eating decreased the risk by 10%. Protective factors were older maternal age and higher educational level, whereas formula feeding, early complementary feeding, greater food enjoyment, and satiety responsiveness increased the risk.

CONCLUSIONS

Small for gestational age, slowness in eating, and feeding practices can be rapid weight gain predictors across the first year of life.

Reciprocal associations between parental feeding practices and child eating behaviours from toddlerhood to early childhood: bivariate latent change analysis in the Gemini cohort

BACKGROUND

Parental feeding practices (PFPs) are a key component of a child's food environment. Parent-child feeding relationships are hypothesised to be bidirectional; however, to date, few large prospective studies have examined this, instead focussing on unidirectional relationships. As such, the direction of relationships between PFPs and children's eating behaviours remains unclear.

METHODS

Data were from Gemini, a population-based sample of children born in England and Wales in 2007. Children's eating behaviours and PFPs were measured at 15/16 months and 5 years using validated psychometric measures (n = 1,858 children). Bivariate Latent Change Score Modelling was used to examine the nature of relationships between PFPs and children's eating behaviours at 15/16 months and 5 years. Models were adjusted to account for clustering of twins within families and for sex of the child, socioeconomic status, gestational age and age of the child at measurement time points.

RESULTS

A reciprocal relationship was observed between instrumental feeding and emotional overeating, with greater instrumental feeding predicting greater increases in emotional overeating (β = .09; 0.03-0.15; p = .004) and vice versa (β = .09; 0.03-0.15; p = .005). Reciprocity was also observed between encouragement to eat nutritious foods and children's enjoyment of food, with greater encouragement predicting greater increases in enjoyment of food (β = .08; 0.02-0.13; p = .006) and vice versa (β = .07; 0.02-0.11; p = .003). Parent-child associations and child-parent associations were also observed.

CONCLUSION

These findings are consistent with the hypothesis that certain feeding practices are used as a 'natural' response to a child expressing a greater interest in and enthusiasm for food, but at the same time, such practices impact the development of eating behaviours by nurturing and encouraging the expression of higher emotional overeating and greater enjoyment of food in preschool years. The findings provide important insights into the PFPs and eating behaviour traits that could be targeted as part of a tailored feeding intervention to support parents of children during the preschool formative years.

Sequential mediation of early temperament and eating behaviors in the pathways from feeding practices to childhood overweight and obesity

Introduction

Childhood eating behaviors and temperament may have important implication for constructing the pathways from maternal feeding practices to childhood overweight and obesity (OW/OB). Examining multiple feeding styles simultaneously to childhood OW/OB is critical through the mediators of early childhood temperament and eating behaviors.

Methods

This cross-sectional study recruited mothers mainly responsible for child care from two hospitals and two healthcare centers in eastern China. Sociodemographic characteristics, and data from the Infant Feeding Style Questionnaire (IFSQ), the short form of Children Behavior Questionnaire [Revised (IBQ-RSF)], and the Child Eating Behavior Questionnaire for toddler (CEBQ-T) were collected. Weight and recumbent length were measured to calculate the age- and sex-specific body mass index (BMI) z-scores (BMIz). The structural equation modeling (SEM) approach was used to examine direct and indirect pathways from five maternal feeding styles to childhood OW/OB through temperament and eating behaviors.

Results

A total of 486 children were recruited, 73 (15.02%) children were OW/OB; the age of the children was 14.55 (SD = 5.14) months, and the age of the mothers was 29.90 (SD = 3.63) years. The responsive feeding exerted significant direct (β = -0.098), indirect (β = -0.136) and total (β = -0.234) effects on childhood OW/OB. Restrictive feeding had significant direct (β = 0.222), indirect (β = 0.102) and total (β = 0.324) effects on childhood OW/OB. Indulgent feeding had significant direct (β = 0.220), indirect (β = 0.063), and total (β = 0.283) effects on childhood OW/OB. Pressuring feeding had significant direct (β = -0.116), indirect (β = -0.096) and total (β = -0.212) effects on childhood OW/OB.

Discussion

There was a direct effect of feeding practices on childhood OW/OB; feeding practices indirectly predicted childhood OW/OB through temperament and eating behaviors in children aged 6-23 months. This study could help governments agencies, policymakers, and healthcare workers to establish optimal intervention programs targeting feeding practices through childhood eating behaviors and temperament to prevent childhood OW/OB.

Parental feeding practices as a response to child appetitive traits in toddlerhood and early childhood: a discordant twin analysis of the Gemini cohort

BACKGROUND

Parental feeding practices (PFPs) have been implicated in the development of children's eating behaviours. However, evidence suggests that feeding practices may also develop in response to their child's weight or emerging appetitive traits. We used the twin design to test the hypothesis that parents develop their feeding practices partly in response to their child's appetite.

METHODS

Data were from Gemini, a population-based cohort of 2402 British families with twins born in 2007. Psychometric measures of PFPs and appetite were completed by parents when their twins were 16-months and 5-years. Within-family analyses including all twins with available data in the sample (n = 1010-1858 pairs), examined if within-pair differences in PFPs were associated with differences in appetitive traits, controlling for differences in birth weight-SDS, early feeding method and child sex. In a subsample of twin pairs who were considerably discordant for appetitive traits by ≥ 1SD (n = 122-544 pairs), the direction and magnitude of within-pair differences in feeding practices was explored.

RESULTS

Within-family variation in parental feeding practices in toddlerhood and early childhood was low (discordance ranged from 0.1 to 6% of the sample), except for pressure to eat (toddlerhood: 19%; early childhood: 32%). Within-pair differences in all appetitive traits were associated with differential use of 'pressure to eat' at both 16-months and 5-years. In the subsample of twins most discordant for appetitive traits, parents used more pressure with the twin expressing lower food responsiveness, lower emotional overeating, lower food enjoyment, higher satiety responsiveness, slower speed of eating, higher emotional undereating and greater fussiness in toddlerhood and early childhood (p-values < 0.001). Effect sizes were small to large at 16-months (η²=0.02-0.09) and 5-years (η²=0.05-0.21).

CONCLUSION

Parents rarely varied their feeding practices between twins in toddlerhood and early childhood, except for pressure. Parents exerted greater pressure on their twin who expressed a poorer appetite compared to their co-twin, suggesting that parents develop a pressuring feeding style when their child expresses a poorer appetite or lower interest in, and enthusiasm for, eating. These findings could be used to guide interventions seeking to support parents in feeding their children in a way that nurtures the development of healthy eating behaviours.

Early life exposures are associated with appetitive traits in infancy: findings from the BiTwin cohort

PURPOSE

To determine the stability of appetitive traits during infancy and their association with early life exposures.

METHODS

Participants were from the BiTwin birth cohort (longitudinal study of Portuguese infants). Appetitive traits at 3 months were measured using the Baby Eating Behaviour Questionnaire (n = 347) and at 12 months with the Children's Eating Behaviour Questionnaire for toddlers (n = 325). Stability was assessed with multi-level models. The association of early life exposures (weight for gestational age, mode of feeding, prematurity, smoking during pregnancy, maternal pre-pregnancy BMI, gestational weight gain, and diabetes mellitus diagnosis) with infant appetitive traits was estimated by multivariable linear regression models.

RESULTS

Appetite traits showed limited stability (ICCs: 0.25-0.34). Associations with early life exposures varied by age. At 3 months, infants of mothers with higher pre-pregnancy BMI and excessive gestational weight gain had low Satiety Responsiveness. In contrast, infants small for gestational age scored high in this trait (β̂ = 0.241; 95% CI 0.056-0.425). Exclusively formula-fed infants presented weak food approach traits at this age, namely low Enjoyment of Food (β̂ = - 0.145; 95% CI - 0.270 to - 0.019) and Food Responsiveness (β̂ = - 0.415; 95% CI - 0.618 to - 0.212). At 12 months, infants who were small for gestational age had low Food Responsiveness (β̂ = - 0.297; 95% CI - 0.523 to - 0.072), in contrast, infants of mothers who gained excessive gestational weight had high scores in this trait. Formula feeding was related to rapid eating (Slowness in Eating: β̂ = - 0.252; 95% CI 0.451 to - 0.054).

CONCLUSION

Early life exposures may play a role in the development of infants' appetitive traits, which then change during the first year of life. Interventions focussed on maternal and infant health may have the potential to shape appetite in infancy.

The Baby's First Bites RCT: Evaluating a Vegetable-Exposure and a Sensitive-Feeding Intervention in Terms of Child Health Outcomes and Maternal Feeding Behavior During Toddlerhood

BACKGROUND

Parenting interventions during the first years of life on what and/or how to feed infants during complementary feeding can promote healthy eating habits.

OBJECTIVES

An intervention promoting repeated exposure to a variety of vegetables [repeated vegetable exposure (RVE); what] and an intervention promoting responding sensitively to child signals during mealtime [video-feedback intervention to promote positive parenting-feeding infants (VIPP-FI); how] were compared, separately and combined (COMBI), with an attention control condition (AC). Primary outcomes were vegetable consumption and self-regulation of energy intake; secondary outcomes were child anthropometrics and maternal feeding practices (sensitive feeding, pressure to eat).

METHODS

Our 4-arm randomized controlled trial included 246 first-time Dutch mothers and their infants. Interventions started when infants were 4-6 mo old and ended at age 16 mo. The present study evaluated effects at 18 (t18) and 24 (t24) mo of age. Vegetable acceptance was assessed using three 24-h dietary recalls, self-regulation of energy intake by an eating-in-the-absence-of-hunger experiment and mother-report, and maternal feeding behavior by observation and mother-report.

RESULTS

Linear mixed model and ANOVA analyses revealed no follow-up group differences regarding child vegetable intake or self-regulatory behavior. The proportion of children with overweight was significantly lower in the COMBI group, compared with the VIPP-FI group at t18 (2% compared with 16%), and with the AC group at t24 (7% compared with 20%), although this finding needs to be interpreted cautiously due to the small number of infants with overweight and nonsignificant effects on the continuous BMI z-score measure (P values: 0.29-0.82). Finally, more sensitive feeding behavior and less pressure to eat was found in the VIPP-FI and COMBI groups, compared with the RVE and AC groups, mostly at t18 (significant effect sizes: d = 0.23-0.64).

CONCLUSIONS

Interventions were not effective in increasing vegetable intake or self-regulation of energy intake. Future research might usefully focus on risk groups such as families who already experience problems around feeding.This trial is registered at clinicaltrials.gov as NCT03348176.

Eating in the absence of hunger in 18-month-old children in a home setting

BACKGROUND

Eating in the absence of hunger (EAH), the susceptibility to eat despite satiety, may increase overweight. While EAH has been established in school-aged children, less is known about it during toddlerhood.

OBJECTIVES

This study assessed to what extent 18-month-old children eat in the absence of hunger, the stability of this behaviour at 24 months and the association of child eating behaviours with EAH.

METHODS

Children were presented with four palatable finger foods (total 275 kcal) after dinner. Univariate GLM's assessed the association between EAH, child satiety and eating behaviours and energy intake of dinner at 18 and 24 months (n = 206 and 103, respectively). Another GLM was run to assess the association between EAH at both time points.

RESULTS

Mean (±SD) energy intakes from dinner and finger foods were 240 kcal (±117) and 40 kcal (±37), respectively. No association was found between energy intake of dinner and finger foods. Enjoyment of food was significantly related to intake of finger foods (P = .005). EAH at 18 months predicted EAH at 24 months.

CONCLUSION

Eighteen-month-old children ate in the absence of hunger, irrespective of satiety. Thus, preceding energy intake was not compensated for. Other factors, for example, enjoyment of food seem to determine finger food intake.

Rationale and design of the Baylor Infant Twin Study-A study assessing obesity-related risk factors from infancy

BACKGROUND

Early childhood (0-3 years) is a critical period for obesity prevention, when tendencies in eating behaviors and physical activity are established. Yet, little is understood about how the environment shapes children's genetic predisposition for these behaviors during this time. The Baylor Infant Twin Study (BITS) is a two phase study, initiated to study obesity risk factors from infancy. Data collection has been completed for Phase 1 in which three sub-studies pilot central measures for Phase 2. A novel infant temperament assessment, based on observations made by trained researchers was piloted in Behavior Observation Pilot Protocol (BOPP) study, a new device for measuring infant feeding parameters (the "orometer") in the Baylor Infant Orometer (BIO), and methods for analyzing DNA methylation in twins of unknown chorionicity in EpiTwin.

METHODS

EpiTwin was a cross-sectional study of neonatal twins, while up to three study visits occurred for the other studies, at 4- (BOPP, BIO), 6- (BOPP), and 12- (BOPP, BIO) of age. Measurements for BOPP and BIO included temperament observations, feeding observations, and body composition assessments while EpiTwin focused on collecting samples of hair, urine, nails, and blood for quantifying methylation levels at 10 metastable epialleles. Additional data collected include demographic information, zygosity, chorionicity, and questionnaire-based measures of infant behaviors.

RESULTS

Recruitment for all three studies was completed in early 2020. EpiTwin recruited 80 twin pairs (50% monochorionic), 31 twin pairs completed the BOPP protocol, and 68 singleton infants participated in BIO.

CONCLUSIONS

The psychometric properties of the data from all three studies are being analyzed currently. The resulting findings will inform the development of the full BITS protocol, with the goal of completing assessments at 4-, 6-, 12-, and 14-month of age for 400 twin pairs.

Fostering infant food texture acceptance: A pilot intervention promoting food texture introduction between 8 and 15 months

Healthy infant feeding practices form the basis of healthy eating behaviour later in life. The effect of providing parents with recommendations on textured food introduction between 8 and 15 months on children's experience with and acceptance of textured foods was studied. Sixty parent/child dyads were randomly assigned to a control group (CG) receiving current French recommendations and an intervention group (IG) receiving a brochure with supplementary advice, tips and monthly counselling on food texture introduction. After the intervention, parents completed self-report measures about the introduction of 188 food items, including purees, soft/small pieces, hard/large pieces and double textures. Children's acceptance of eight textured foods was assessed in a laboratory setting. Parents in the IG introduced more soft/small food pieces (P = 0.004) but not more complex textures (P = 0.15). There was no group difference in children acceptance for any of the textured foods offered in the laboratory. Independent of their study group, children's exposure to texture was associated with birth order, self-feeding with fingers, low gagging frequency and seldom use of commercial baby foods. Higher acceptance was associated with higher exposure to food pieces but not to pureed foods (either smooth or rough) and with children's eating behavioural traits (high food enjoyment, high food responsiveness and low food fussiness). This pilot intervention demonstrated that providing information can be effective in promoting the introduction of small and soft food pieces, but the most effective way to influence the introduction of more challenging textures (hard pieces and double texture) is uncertain. Further research should focus on the identification of barriers to complex texture introduction and on how building on this knowledge for a population-based public health intervention.

Common etiological architecture underlying reward responsiveness, externally driven eating behaviors, and BMI in childhood: findings from the Gemini twin cohort

BACKGROUND

Studies have reported that impulsivity predicts childhood BMI and that the association is mediated by eating behaviors. One aspect of impulsivity-potentially crucial in the obesity context-is reward responsiveness, which may predispose to responsiveness to palatable food cues. The behavioral susceptibility theory hypothesizes that genetic susceptibility to obesity operates partly via genetically determined differences in appetite regulation. Reward responsiveness may therefore be one of the neuro-endophenotypes that mediates genetic susceptibility to obesity.

OBJECTIVE

To test whether reward responsiveness, eating behaviors, and child BMI share common genetic architecture.

METHODS

We examined reward responsiveness, eating behaviors, and BMI in 5-year-old children from Gemini, a UK birth cohort of 2402 twin pairs born in 2007. All measures were collected by parent report. Reward responsiveness was derived from the Behavioral Approach System. Compulsion to eat and eating for pleasure was measured with the "food responsiveness" scale of the Child Eating Behavior Questionnaire. Wanting to eat in response to environmental food cues was measured with the "external eating" scale of the Dutch Eating Behavior Questionnaire. Maximum-likelihood structural equation modeling was used to establish underlying common genetic and environmental influences.

RESULTS

There were significant positive phenotypic correlations between all traits except for reward responsiveness and BMI. Genetic factors explained the majority of the association between food responsiveness and external eating (74%, 95% CI: 61, 87), whereas common shared environmental factors explained the majority of the associations between reward responsiveness with both food responsiveness (55%, 95% CI: 20, 90) and external eating (70%, 95% CI: 39, 100).

CONCLUSIONS

Our study demonstrates the importance of common environmental factors in the shared etiology between reward responsiveness and childhood eating behaviors. However, the common etiology underlying both reward responsiveness and BMI is unclear, as there was no phenotypic correlation between reward responsiveness and BMI at this age. Further longitudinal research needs to detangle this complex relationship throughout development.

Genotype-Environment Correlation and Its Relation to Personality - A Twin and Family Study

The aim of the study was to examine the Family and School Psychosocial Environment (FSPE) questionnaire in relation to a possible genotype-environment correlation and genetic mediation between the FSPE variables and personality variables, assessed by the Junior Eysenck Personality Questionnaire. A sample of 506 Swedish children aged 10-20 years from 253 families were recruited via the Swedish state population and address register and SchoolList.Eu. The children were divided into 253 pairs: 46 monozygotic twin pairs, 42 dizygotic twin pairs, 140 pairs of full siblings and 25 pairs of half-siblings. The behavioral genetic analysis showed that both FSPE factors, Warmth and Conflicts, may be partly influenced by genetic factors (suggesting genotype-environment correlation) and that nonadditive genetic factors may mediate the relationship between FSPE factors and psychoticism/antisocial personality (P). An indication of a special shared monozygotic twin environment was found for P and Lie/social desirability, but based on prior research findings this factor may have a minor influence on P and L. P and L were negatively correlated, and the relationship seems to be partly mediated by nonadditive genetic factors. Nonshared environment and measurement errors seem to be the most influential mediating factors, but none of the cross-twin cross-dimension correlations suggest a common shared environmental mediating factor.

Does contact with the justice system deter or promote future delinquency? Results from a longitudinal study of British adolescent twins

What impact does formal punishment have on antisocial conduct-does it deter or promote it? The findings from a long line of research on the labeling tradition indicate formal punishments have the opposite-of-intended consequence of promoting future misbehavior. In another body of work, the results show support for deterrence-based hypotheses that punishment deters future misbehavior. So, which is it? We draw on a nationally representative sample of British adolescent twins from the Environmental Risk (E-Risk) Longitudinal Twin Study to perform a robust test of the deterrence versus labeling question. We leverage a powerful research design in which twins can serve as the counterfactual for their co-twin, thereby ruling out many sources of confounding that have likely impacted prior studies. The pattern of findings provides support for labeling theory, showing that contact with the justice system-through spending a night in jail/prison, being issued an anti-social behaviour order (ASBO), or having an official record-promotes delinquency. We conclude by discussing the impact these findings may have on criminologists' and practitioners' perspective on the role of the juvenile justice system in society.

Baby's first bites: a randomized controlled trial to assess the effects of vegetable-exposure and sensitive feeding on vegetable acceptance, eating behavior and weight gain in infants and toddlers

BACKGROUND

The start of complementary feeding in infancy plays an essential role in promoting healthy eating habits. Evidence shows that it is important what infants are offered during this first introduction of solid foods: e.g. starting exclusively with vegetables is more successful for vegetable acceptance than starting with fruits. How infants are introduced to solid foods also matters: if parents are sensitive and responsive to infant cues during feeding, this may promote self-regulation of energy intake and a healthy weight. However, the effectiveness of the what and the how of complementary feeding has never been experimentally tested in the same study. In the current project the what and how (and their combination) are tested in one study to determine their relative importance for fostering vegetable acceptance and self-regulation of energy intake in infants.

METHODS

A four-arm randomized controlled trial (Baby's First Bites (BFB)) was designed for 240 first-time Dutch mothers and their infants, 60 per arm. In this trial, we compare the effectiveness of (a) a vegetable-exposure intervention focusing on the what in complementary feeding; (b) a sensitive feeding intervention focusing on the how in complementary feeding, (c) a combined intervention focusing on the what and how in complementary feeding; (d) an attention-control group. All mothers participate in five sessions spread over the first year of eating solid foods (child age 4-16 months). Primary outcomes are vegetable consumption, vegetable liking and self-regulation of energy intake. Secondary outcomes are child eating behaviors, child anthropometrics and maternal feeding behavior. Outcomes are assessed before, during and directly after the interventions (child age 18 months), and when children are 24 and 36 months old.

DISCUSSION

The outcomes are expected to assess the impact of the interventions and provide new insights into the mechanisms underlying the development of vegetable acceptance, self-regulation and healthy eating patterns in infants and toddlers, as well as the prevention of overweight. The results may be used to improve current dietary advice given to parents of their young children on complementary feeding.

TRIAL REGISTRATION

The trial was retrospectively registered during inclusion of participants at the Netherlands National Trial Register (identifier NTR6572 ) and at ClinicalTrials.gov ( NCT03348176 ). Protocol issue date: 1 April 2018; version number 1.

Family Spirit Nurture (FSN) - a randomized controlled trial to prevent early childhood obesity in American Indian populations: trial rationale and study protocol

BACKGROUND

Childhood overweight and obesity is a persistent public health issue in the US. Risk for obesity and obesity-related morbidity throughout the life course begins in utero. Native Americans suffer the greatest disparities in the US in childhood overweight and obesity status of any racial or ethnic group. Existing early childhood home-visiting interventions provide an opportunity for addressing obesity during the first 1000 days. However, to date, no evidence-based model has been specifically designed to comprehensively target early childhood obesity prevention.

METHODS

This study is a randomized controlled trial to test the efficacy of home-visiting intervention, called Family Spirit Nurture, on reducing early childhood obesity in Native American children. Participants are expectant Native American mothers ages 14-24 and their child, enrolled from pregnancy to 24 months postpartum and randomized 1:1 to receive the Family Spirit Nurture intervention or a control condition. The intervention includes 36 lessons delivered one-on-one by locally-hired Native American Family Health Coaches to participating mothers from pregnancy until 18 months postpartum. A mixed methods assessment includes maternal self-reports, maternal and child observations, and physical and biological data collected at 11 time points from 32 weeks gestation to 2 years postpartum to measure the intervention's primary impact on maternal feeding behaviors; children's healthy diet and physical activity; children's weight status. Secondary measures include maternal psychosocial factors; household food and water security; infant sleep and temperament; and maternal and child metabolic status.

DISCUSSION

None of the 20 current federally-endorsed home-visiting models have demonstrated impacts on preventing early childhood obesity. The original Family Spirit program, upon which Family Spirit Nurture is based, demonstrated effect on maternal and child behavioral health, not including obesity related risk factors. This trial has potential to inform the effectiveness of home-visiting intervention to reduce obesity risk for tribal communities and other vulnerable populations and expand public health solutions for the world's obesity crisis.

TRIAL REGISTRATION

Clinicaltrials.gov (Identifier: NCT03334266 - Preventing Early Childhood Obesity, Part 2: Family Spirit Nurture, Prenatal - 18 Months; Retrospectively registered on 07 November 2017).

Sleep duration and quality are associated with eating behavior in low-income toddlers

OBJECTIVE

The present study examined whether different sleep health parameters (duration, timing, and quality) are associated with obesity-related eating behaviors including emotional overeating, food responsiveness, enjoyment of food, satiety responsiveness, and eating in the absence of hunger (EAH), during toddlerhood.

DESIGN

Among 134 low-income 33-month-old children, parents reported on child sleep parameters, including sleep quality (Children's Sleep Wake Scale; CSWS) and usual bedtimes and wake times on weekdays and weekends (weeknight sleep duration, weekday-to-weekend bedtime delay). Child eating behaviors were assessed using both observed and parent-report measures. Child Emotional Overeating, Food Responsiveness, Enjoyment of Food, and Satiety Responsiveness were measured by parent report using the Child Eating Behavior Questionnaire-Toddler. Observed child EAH was evaluated by measuring kilocalories of palatable foods consumed following a meal. Multivariable linear regression was used to examine the associations between sleep parameters and eating behaviors.

RESULTS

Poorer child sleep quality was associated with greater Emotional Overeating (standardized β = -0.20 (SE 0.09), p < .05) and greater Food Responsiveness (β = -0.18 (SE 0.09), p < .05). Shorter child nighttime sleep duration was associated with greater EAH kcal consumed (standardized β = -0.22 (SE 0.09), p < .05). Child bedtime delay was not associated with any of the eating behaviors, and no child sleep variables were associated with either Enjoyment of Food or Satiety Responsiveness.

CONCLUSIONS

Shorter nocturnal sleep duration and poorer sleep quality during toddlerhood were associated with some, but not all, of the obesity-related eating behaviors. Poor sleep health may promote childhood obesity risk through different eating behavior pathways. As children growing up in poverty may experience greater sleep decrements, sleep duration and sleep quality may be important targets for intervention among low-income families with young children.

Evidence for gene-environment correlation in child feeding: Links between common genetic variation for BMI in children and parental feeding practices

The parental feeding practices (PFPs) of excessive restriction of food intake (‘restriction’) and pressure to increase food consumption (‘pressure’) have been argued to causally influence child weight in opposite directions (high restriction causing overweight; high pressure causing underweight). However child weight could also ‘elicit’ PFPs. A novel approach is to investigate gene-environment correlation between child genetic influences on BMI and PFPs. Genome-wide polygenic scores (GPS) combining BMI-associated variants were created for 10,346 children (including 3,320 DZ twin pairs) from the Twins Early Development Study using results from an independent genome-wide association study meta-analysis. Parental ‘restriction’ and ‘pressure’ were assessed using the Child Feeding Questionnaire. Child BMI standard deviation scores (BMI-SDS) were calculated from children’s height and weight at age 10. Linear regression and fixed family effect models were used to test between- (n = 4,445 individuals) and within-family (n = 2,164 DZ pairs) associations between the GPS and PFPs. In addition, we performed multivariate twin analyses (n = 4,375 twin pairs) to estimate the heritabilities of PFPs and the genetic correlations between BMI-SDS and PFPs. The GPS was correlated with BMI-SDS (β = 0.20, p = 2.41x10^-38). Consistent with the gene-environment correlation hypothesis, child BMI GPS was positively associated with ‘restriction’ (β = 0.05, p = 4.19x10^-4), and negatively associated with ‘pressure’ (β = -0.08, p = 2.70x10^-7). These results remained consistent after controlling for parental BMI, and after controlling for overall family contributions (within-family analyses). Heritabilities for ‘restriction’ (43% [40–47%]) and ‘pressure’ (54% [50–59%]) were moderate-to-high. Twin-based genetic correlations were moderate and positive between BMI-SDS and ‘restriction’ (r_A = 0.28 [0.23–0.32]), and substantial and negative between BMI-SDS and ‘pressure’ (r_A = -0.48 [-0.52 - -0.44]. Results suggest that the degree to which parents limit or encourage children’s food intake is partly influenced by children’s genetic predispositions to higher or lower BMI. These findings point to an evocative gene-environment correlation in which heritable characteristics in the child elicit parental feeding behaviour.

It is widely believed that parents influence their child’s BMI via certain feeding practices. For example, rigid restriction has been argued to cause overweight, and pressuring to eat to cause underweight. However, recent longitudinal research has not supported this model. An alternative hypothesis is that child BMI, which has a strong genetic basis, evokes parental feeding practices (‘gene-environment correlation’). To test this, we applied two genetic methods in a large sample of 10-year-old children from the Twins Early Development Study: a polygenic score analysis (DNA-based score of common genetic variants associated with BMI in genome-wide meta-analyses), and a twin analysis (comparing resemblance between identical and non-identical twin pairs). Polygenic scores correlated positively with parental restriction of food intake (‘restriction’; β = 0.05, p = 4.19x10^-4), and negatively with parental pressure to increase food intake (‘pressure’; β = -0.08, p = 2.70x10^-7). Associations were unchanged after controlling for all genetic and environmental effects shared within families. Results from twin analyses were consistent. ‘Restriction’ (43%) and ‘pressure’ (54%) were substantially heritable, and a positive genetic correlation between child BMI and ‘restriction’ (r_A = 0.28), and negative genetic correlation between child BMI and ‘pressure’ (r_A = -0.48) emerged. These findings challenge the prevailing view that parental behaviours are the sole cause of child BMI by supporting an alternate hypothesis that child BMI also causes parental feeding behaviour.