Purpose: Sleep in early childhood is important for child development. While most studies reported unfavourable short-term effects of breastfeeding on infant sleep-wake behaviours that potentially attenuate over time, findings remained inconsistent. This study investigates the associations between breastfeeding and longitudinal day-, night- and total sleep trajectories, and sleep-wake behaviours in healthy infants and preschool children.

Methods: In a prospective cohort study, 654 caregivers of fully-breastfed (n = 158), partially-breastfed (n = 208) and formula-fed (n = 288) naturally-conceived term born singletons, had completed the Brief Infant Sleep Questionnaire (BISQ) (3, 6, 9, 12, 18 and 24 months) and/or Children’s Sleep Habits Questionnaire (CSHQ) (54 months). Group-based multi-trajectory analyses derived four day- (n = 243), three night- (n = 248) and/or four total- (n = 241) sleep trajectories, with each differing in length of sleep duration (short/moderate/long) and variability (variable/consistent). Infant sleep-wake behaviours (day/night/total sleep durations, and duration/number of night awakenings) were also assessed for associations with breastfeeding status from 3 to 24 months.

Results: After adjusting for potential covariates, formula-fed infants were significantly more likely to exhibit short variable night- [OR=4.43 (95% CI 1.86 to 10.54)] and total sleep trajectories [OR=6.51 (95% CI 2.47 to 17.17)] and less likely to exhibit long consistent night-[OR=0.36 (95% CI 0.15 to 0.85)] and total sleep trajectories [OR=0.32 (95% CI 0.13 to 0.80)], compared to fully-breastfed infants. Partially-breastfed infants did not differ from fully-breastfed infants for both night- and total sleep trajectories. No significant differences were found between all three breastfeeding groups for day sleep trajectories. Fully-breastfed infants have longer night- (6, 9, 12 and 24 months), day- (3 months) and total- (3 and 9 months) sleep durations, than formula-fed infants, albeit greater number of night awakenings (from 3 to 12 months).

Conclusions: Despite more night awakenings, fully-breastfed infants have overall longer sleep duration and more likely to develop long consistent (and less likely to develop short variable) night- and total sleep trajectories, compared to fully formula-fed infants.

Purpose: Fat-soluble vitamins during pregnancy are important for fetal growth and development. This study was conducted to explore the association between maternal serum vitamin A, E and D status during pregnancy and infant birth weight. Relevant studies are rare in China, and the existing ones were poorly designed, e.g. having a small sample size, measuring vitamins at  partum only, not matching between observation and control groups, not controlling for covariates, not detailing the study design. The present study was a large-scale retrospective cohort among the Chinese population.

Methods: A total of 19 640 women with singleton deliveries were included. Data were collected by the hospital electronic information system. Maternal serum vitamin A, E and D concentrations were measured during pregnancy. Logistic regression was performed to estimate the association between the vitamin status and low birth weight (LBW) or macrosomia.

Results: The prevalence of LBW and macrosomia in the birth cohort was 2.6% and 8.2%, respectively. Women with excessive vitamin E were more likely to have macrosomia (OR 1·30, 95 % CI 1·07, 1·59) compared with adequate concentration. When focusing on Z scores, there was a positive association between vitamin E and macrosomia in the first (OR 1·07, 95 % CI 1·00, 1·14), second (OR 1·27, 95 % CI 1·11, 1·46) and third (OR 1·28, 95 % CI 1·06, 1·54) trimesters; vitamin A was positively associated with LBW in the first (OR 1·14, 95 % CI 1·01, 1·29), second (OR 1·31, 95 % CI 1·05, 1·63) and third (OR 2·00, 95 % CI 1·45, 2·74) trimesters and negatively associated with macrosomia in the second (OR 0·79, 95 % CI 0·70, 0·89) and third (OR 0·77, 95 % CI 0·62, 0·95) trimesters. 

Conclusions: The study identified that high concentrations of vitamin E are associated with macrosomia. Maintaining a moderate concentration of vitamin A during pregnancy might be beneficial to achieve optimal birth weight. Further studies to explore the mechanism of above associations are warranted.

Purpose: Core Outcome Sets (COS) are agreed minimum sets of outcomes recommended for measurement in studies for specific conditions or areas of health.  COS development aims to improve the consistency, comparability and transparency of study findings and can help to reduce research waste.  Few COS for public health interventions currently exist and there are no published COS that can be applied to obesity prevention interventions in children aged from birth to five years that include outcomes for multiple behaviour domains (e.g. food intake, movement, sleep).  This study describes the development of a COS for randomised controlled trials (RCTs) evaluating lifestyle interventions for the prevention of obesity in 0-5 year olds (COS-EPOCH), and highlights some of the challenges faced in COS development.

Methods: Overseen by an international Steering Group, the COS development process follows the Core Outcome Set-STAndards for Development recommendations.  Development consists of three stages: (i) a scoping review of early childhood obesity prevention RCTs, identifying potential outcomes and measurement instruments; (ii) a modified Delphi study to determine core outcomes by relevant stakeholder group, followed by a consensus meeting to finalise core outcome recommendations; and, (iii) determination of recommended measurement instruments.

Results/findings: Scoping review identified 170 relevant studies, with preliminary findings demonstrating there are a large number of outcomes currently collected in early childhood obesity prevention RCTs, and a broad range of outcome measurement instruments and methodologies employed.  This high level of variation between studies makes evidence synthesis challenging, and further highlights the need for an agreed set of core outcomes.  Delphi study development and recruitment is underway.  Challenges in the development of the COS-EPOCH include the multiplicity of potential outcomes for inclusion, and the heterogeneity in completeness of study reporting in trial registries and the literature.

Conclusions: The development of the COS-EPOCH will provide trialists with standardised sets of outcomes spanning the early childhood timeframe that takes into account this unique period of child development and incorporates multiple risk factors targeted in interventions. Effective dissemination of the COS-EPOCH will play a critical role in its future uptake.

Purpose: Nutrition education in schools plays an essential role in child health and wellbeing, with research showing such programs can improve child dietary knowledge and behaviours. Although teachers are key to nutrition education delivery, they report that a lack of time often hinders their ability to teach nutrition as a stand-alone subject. An education program that integrates nutrition with core curricular subjects may help address this barrier. This study aimed to examine the impact of a teaching unit integrating nutrition with mathematics on child nutrition knowledge (CUPS: Cross-curricular Unit on Portion Size).

Methods: Four primary schools participated in the CUPS randomised controlled trial, conducted across one to four weeks (n=69 students in Year 3/4). Students randomly allocated by class groups to the intervention arm (n=44) received six lessons on food groups, portion/serve size, volume and capacity involving experiential learning with mathematics cubes and food models. Students in the wait-list control group (n=25) continued usual lessons. Nutrition knowledge was determined using a survey (CNK-AU), administered pre-intervention, immediately post-intervention and 4 weeks after intervention completion. Linear mixed models were used to determine the impact of treatment group, time and the group-by-time as fixed effects.

Results/findings: Linear mixed models accounting for clustering at the class level displayed a significant improvement in overall nutrition knowledge scores for the CUPS group compared to the control condition at both post-intervention time points (P<.01). Adjusted difference in change for nutrition knowledge scores from baseline to post-intervention and baseline to 4 weeks post-intervention were 4.84 (95% CI [2.35-7.32]) and 3.40 (95% CI [0.88-5.95]) respectively. Students scored particularly better on questions about healthy choices and recommended serve sizes.

Conclusions: The CUPS program uses an integrative approach to teach primary school children about healthy eating, food portions and serve sizes while aligning with the mathematics curriculum. Findings provide evidence for effectiveness of this teaching strategy to improve child nutrition knowledge. Future cross-curricular nutrition education interventions should investigate long-term effects within a larger sample to fully explore effectiveness.

Traditional food marketing stimulates adolescents’ consumption of energy-dense, nutrient-poor foods. These dietary behaviors may track into adulthood and lead to weight gain, obesity, and related non-communicable diseases. While social media use in adolescents has proliferated, little is known about the content of food marketing within these platforms, and how this impacts adolescents’ dietary behaviours. This paper aimed to obtain expert insights on factors involved in the association between social media food marketing (SMFM) and adolescent dietary behaviours, and to explore their views on key priorities, challenges and strategies for future SMFM research and policies.
One-on-one semi-structured interviews (n=17) were conducted with experts in the fields of public health (policy), nutrition science, social media marketing, adolescent medicine, clinical psychology, behavioural sciences, communication, food industry, social influencing, and social marketing.
The experts’ collective responses identified that the line between food content posted by social media users and food companies is blurred and social media food marketing is subject to multiple interpretations. Adolescents’ processing of SMFM may be mostly implicit, involving social comparisons, emotional engagement, and attaching symbolic meanings to the promoted foods. Moderating factors potentially influencing adolescents’ response to SMFM messages include adolescent-specific and SMFM-specific factors. The first largely refers to the unique developmental phase of adolescence, e.g. adolescents are typically more impulsive and more sensitive to peer behaviors, and they are still developing their own identity, among others. The latter includes characteristics that make SMFM messages particularly effective in targeting adolescents, e.g. they are engaging, interactive, personalized, and they show other’s engagement, among others. Experts agreed there is limited scientific evidence on adolescent-targeted SMFM, and expressed concern that there are no current regulations in place to protect adolescents from unhealthy SMFM, as adolescents are active social media users and their cognitive abilities make them vulnerable to implicit marketing tactics. Adolescent-targeted SMFM content should be controlled by either encouraging healthy food marketing or limiting junk food marketing.
Creating clear and universal SMFM definitions, and prioritizing both quantitative research on SMFM exposure and qualitative research to obtain adolescents’ perspectives, are all crucial in advocating for regulatory restrictions on adolescent-targeted SMFM content.

Adolescent-targeted food marketing mostly concerns energy-dense, nutrient-poor foods, encouraging increased consumption of these foods. With the rise of social media marketing, strategies to market foods to adolescents have transformed into more advanced and implicit tactics. While adolescents’ social media use has increased rapidly over time, leading to over 9000 social media food marketing (SMFM) exposures annually, to date no research has examined to what extent adolescents are aware of or appreciate SMFM content. This study aimed to provide insight into adolescents’ awareness and appreciation of SMFM.
Semi-structured online one-on-one interviews with 16 Dutch adolescents (mean age 14.5 years) were conducted, in which SMFM instances from Instagram, Snapchat, TikTok and Youtube were extensively discussed. Interview transcripts were coded and thematically analysed.
The results showed that participants used specific criteria for recognising social media content as food advertising. Specifically, when food content was posted by a food brand account, they considered it food advertisement, but when it was posted by friends they did not. When food content was posted by a famous social media influencer, recognition of the advertisement differed. Participants’ recognition of food advertising was variable for food content disclosing commercial intent. With regard to appreciation, participants had different perspectives on the reliability of the source (brand, celebrity or friend) and based their preference on this. Participants generally preferred the marketing of non-core foods.
This study contributes to a relatively unexplored research area. Adolescents’ awareness and appreciation of SMFM is impacted by the level of integration of SMFM into social media content, with the source of food content and the use of disclosures as major influential factors. Since adolescents mostly prefer non-core food content on social media, this may have significant implications for their food consumption and health. Hence, there is an urgent need for strategies to help adolescents become more resilient to SMFM content. Moreover, it is recommended that future research complements the current findings by exploring more objective measures of adolescents’ awareness or recognition of SMFM, i.e. through experimental study designs.