Effects of early intervention on dietary intake and its mediating role on cognitive functioning: a randomised controlled trial

Can Early Intervention have a Sustained Effect on Human Capital?

Many early intervention studies experience a dissolution of treatment effects in the aftermath of the intervention. Using a randomized trial, this paper examines the impact of Preparing for Life, a pregnancy to age five home visiting and parenting program, on outcomes in middle childhood. I find significant treatment effects on cognitive skills (0.55SD) and school achievement tests (0.30-0.54SD) at age nine. There is no impact on socio-emotional skills and there is little evidence of treatment heterogeneity by gender, birth order, or distribution of ability. The effects are mainly driven by improvements in early parental beliefs.

The effectiveness of interventions during the first 1,000 days to improve energy balance-related behaviors or prevent overweight/obesity in children from socio-economically disadvantaged families of high-income countries: a systematic review

This narrative systematic review examined effectiveness of interventions during pregnancy and up to 2 years of age in improving energy balance-related behaviors or prevent overweight/obesity in children from families experiencing socio-economic disadvantage. We identified 24 interventions, from 33 articles, since 1990. Overall, despite their heterogeneity and variability in internal and external validity, there was some evidence of beneficial impact of interventions on obesity risk (4/15), and associated behaviors, e.g.: breastfeeding (9/18), responsive feeding (11/16), diet (7/8), sedentary (1/3) and movement (4/7) behaviors, and sleep (1/2). The most effective interventions aimed at promoting breastfeeding commenced antenatally; this was similar for the prevention of obesity, provided the intervention continued for at least 2 years postnatally and was multi-behavioral. Effective interventions were more likely to target first-time mothers and involve professional delivery agents, multidisciplinary teams and peer groups. Among ethnic/racial minorities, interventions delivered by lay agents had some impact on dietary behavior but not weight outcomes. Co-creation with stakeholders, including parents, and adherence to theoretical frameworks were additional ingredients for more pragmatic, inclusive, non-judgmental, and effective programs. The growing body of evidence on obesity prevention interventions targeting families experiencing socio-economic disadvantage is promising for reducing early inequalities in obesity risk.

Cognitive interventions in children and adolescents from low socioeconomic status backgrounds: a systematic review protocol of randomized controlled trials

BACKGROUND

Many studies have evaluated the effects that a lack of resources has in children's physical and cognitive development. Although there are reviews that have focused on applied interventions from different perspectives, there is still a need for a comprehensive review of what has been attempted with these children from the cognitive intervention field. The aim of this paper is to present a protocol for a systematic review collecting randomized controlled trials (RCTs) studies whose purpose was to enhance cognitive development through the implementation of cognitive interventions in children and adolescents (< 18 years old) from low socioeconomic Status (SES) settings.

METHODS

The following databases will be searched: Web of Science (WoS core collection), PsycINFO, Cochrane Central Register of Controlled Trial, ERIC, PubMed, ICTRP and Opengrey Register (System for Information of Grey Literature in Europe). Searches will be adapted for each database. Additionally, the reference list of articles included in the review will also be searched. As part of this process, two reviewers will determine, independently, the suitability of each article taking into account predefined inclusion/exclusion criteria. Pertinent data will then be extracted, including sample characteristics, specifics of the intervention, and outcomes, as well as follow-up measures. Internal validity will be assessed using the Cochrane Risk of Bias Tool. A quantitative synthesis of results will be conducted using a meta-analysis. However, if a meta-analysis is difficult to implement due to the diversity of the studies (for example, in terms of measures used to estimate the effect size, intervention types, outcomes, etc.), the technique synthesis without meta-analysis (SWiM) will be used. A description of outcome measures will be provided, as measured by validated neuropsychological instruments of any cognitive function.

DISCUSSION

The systematic review will offer a framework based on evidence to organisations, institutions, and experts who want to implement or promote interventions aimed at enhancing cognitive domains in children and adolescents who live in disadvantaged contexts.

SYSTEMATIC REVIEW REGISTRATION

This protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 16 March 2020 (registration number: CDR42020150238).

Association of Protein Intake during the Second Year of Life with Weight Gain-Related Outcomes in Childhood: A Systematic Review

There is accumulating evidence that early protein intake is related with weight gain in childhood. However, the evidence is mostly limited to the first year of life, whereas the high-weight-gain-velocity period extends up to about 2 years of age. We aimed to investigate whether protein intake during the second year of life is associated with higher weight gain and obesity risk later in childhood. We conducted a systematic review with searches in both PubMed®/MEDLINE® and the Cochrane Central Register of Controlled Trials. Ten studies that assessed a total of 46,170 children were identified. We found moderate-quality evidence of an association of protein intake during the second year of life with fat mass at 2 years and at 7 years. Effects on other outcomes such as body mass index (BMI), obesity risk, or adiposity rebound onset were inconclusive due to both heterogeneity and low evidence. We conclude that higher protein intakes during the second year of life are likely to increase fatness in childhood, but there is limited evidence regarding the association with other outcomes such as body mass index or change in adiposity rebound onset. Further well-designed and adequately powered clinical trials are needed since this issue has considerable public health relevance.

The measurement of the mediator and its influence on statistical mediation conclusions

In psychology, the causal process between 2 variables can be studied with statistical mediation analysis. To make a causal interpretation about the relation between variables, researchers who use the statistical mediation model make many assumptions about the variables in the model, among which are measurement assumptions about the mediator. For example, researchers often assume that the measure of the mediator yields scores that are reliable and that have a valid interpretation. In this article, we address how several measurement challenges affect the conclusions of statistical mediation analysis, and how researchers can use different psychometric models to study theoretically different causal processes. We use simulated data sets to illustrate how 10 well-fitting and theoretically sound statistical mediation models could significantly detect the indirect effect or miss it entirely depending on how the mediator is represented in the model. In the example, power to detect the indirect effect varied by the amount of true mediator variance that the psychometric model of the mediator was able to isolate. Different strategies to incorporate psychometric methods into mediation research are discussed and future directions are considered. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Interventions for increasing fruit and vegetable consumption in children aged five years and under

BACKGROUND

Insufficient consumption of fruits and vegetables in childhood increases the risk of future non-communicable diseases, including cardiovascular disease. Testing the effects of interventions to increase consumption of fruit and vegetables, including those focused on specific child-feeding strategies or broader multicomponent interventions targeting the home or childcare environment is required to assess the potential to reduce this disease burden.

OBJECTIVES

To assess the effectiveness, cost effectiveness and associated adverse events of interventions designed to increase the consumption of fruit, vegetables or both amongst children aged five years and under.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and two clinical trials registries to identify eligible trials on 25 January 2020. We searched Proquest Dissertations and Theses in November 2019. We reviewed reference lists of included trials and handsearched three international nutrition journals. We contacted authors of included trials to identify further potentially relevant trials.

SELECTION CRITERIA

We included randomised controlled trials, including cluster-randomised controlled trials and cross-over trials, of any intervention primarily targeting consumption of fruit, vegetables or both among children aged five years and under, and incorporating a dietary or biochemical assessment of fruit or vegetable consumption. Two review authors independently screened titles and abstracts of identified papers; a third review author resolved disagreements.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risks of bias of included trials; a third review author resolved disagreements. Due to unexplained heterogeneity, we used random-effects models in meta-analyses for the primary review outcomes where we identified sufficient trials. We calculated standardised mean differences (SMDs) to account for the heterogeneity of fruit and vegetable consumption measures. We conducted assessments of risks of bias and evaluated the quality of evidence (GRADE approach) using Cochrane procedures.

MAIN RESULTS

We included 80 trials with 218 trial arms and 12,965 participants. Fifty trials examined the impact of child-feeding practices (e.g. repeated food exposure) in increasing child vegetable intake. Fifteen trials examined the impact of parent nutrition education only in increasing child fruit and vegetable intake. Fourteen trials examined the impact of multicomponent interventions (e.g. parent nutrition education and preschool policy changes) in increasing child fruit and vegetable intake. Two trials examined the effect of a nutrition education intervention delivered to children in increasing child fruit and vegetable intake. One trial examined the impact of a child-focused mindfulness intervention in increasing vegetable intake. We judged 23 of the 80 included trials as free from high risks of bias across all domains. Performance, detection and attrition bias were the most common domains judged at high risk of bias for the remaining trials. There is low-quality evidence that child-feeding practices versus no intervention may have a small positive effect on child vegetable consumption, equivalent to an increase of 5.30 grams as-desired consumption of vegetables (SMD 0.50, 95% CI 0.29 to 0.71; 19 trials, 2140 participants; mean post-intervention follow-up = 8.3 weeks). Multicomponent interventions versus no intervention has a small effect on child consumption of fruit and vegetables (SMD 0.32, 95% CI 0.09 to 0.55; 9 trials, 2961 participants; moderate-quality evidence; mean post-intervention follow-up = 5.4 weeks), equivalent to an increase of 0.34 cups of fruit and vegetables a day. It is uncertain whether there are any short-term differences in child consumption of fruit and vegetables in meta-analyses of trials examining parent nutrition education versus no intervention (SMD 0.13, 95% CI -0.02 to 0.28; 11 trials, 3050 participants; very low-quality evidence; mean post-intervention follow-up = 13.2 weeks). We were unable to pool child nutrition education interventions in meta-analysis; both trials reported a positive intervention effect on child consumption of fruit and vegetables (low-quality evidence). Very few trials reported long-term effectiveness (6 trials), cost effectiveness (1 trial) or unintended adverse consequences of interventions (2 trials), limiting our ability to assess these outcomes. Trials reported receiving governmental or charitable funds, except for four trials reporting industry funding.

AUTHORS' CONCLUSIONS

Despite identifying 80 eligible trials of various intervention approaches, the evidence for how to increase children's fruit and vegetable consumption remains limited in terms of quality of evidence and magnitude of effect. Of the types of interventions identified, there was moderate-quality evidence that multicomponent interventions probably lead to, and low-quality evidence that child-feeding practice may lead to, only small increases in fruit and vegetable consumption in children aged five years and under. It is uncertain whether parent nutrition education or child nutrition education interventions alone are effective in increasing fruit and vegetable consumption in children aged five years and under. Our confidence in effect estimates for all intervention approaches, with the exception of multicomponent interventions, is limited on the basis of the very low to low-quality evidence. Long-term follow-up of at least 12 months is required and future research should adopt more rigorous methods to advance the field. This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Higher maternal plasma β-cryptoxanthin concentration is associated with better cognitive and motor development in offspring at 2 years of age

PURPOSE

Current literature on the roles of α-, β-carotene and β-cryptoxanthin in neurocognitive function has largely focused on preventing cognitive decline in older people, and less on neuro-development in children. We examined the relations of maternal plasma carotenoids concentrations with offspring cognitive development up to age 4.5 years in the Growing Up in Singapore Towards healthy Outcomes mother-offspring cohort study.

METHODS

Maternal plasma α-, β-carotene and β-cryptoxanthin concentrations at delivery were determined by ultra-performance liquid chromatography. Children's cognition was assessed at ages 2 (Bayley Scales of Infant and Toddler Development) and 4.5 (Kaufman Brief Intelligence Test) years. Associations were examined in 419 mother-offspring pairs using linear regressions adjusting for key confounders.

RESULTS

Median and interquartile range of maternal plasma concentrations (mg/L) were: α-carotene 0.052 (0.032, 0.081), β-carotene 0.189 (0.134, 0.286), and β-cryptoxanthin 0.199 (0.123, 0.304). In 2 years old children, higher maternal carotenoids [per standard deviation (SD) log-concentration] were positively associated with neurocognitive functions: β-cryptoxanthin with higher scores in cognitive [β = 0.18, (0.08, 0.28) SD], receptive language [β = 0.17 (0.07, 0.27) SD], fine motor [β = 0.16 (0.05, 0.26) SD], and gross motor [β = 0.16 (0.06, 0.27) SD] scales; β-carotene with higher cognitive score [β = 0.17 (0.05, 0.29) SD]. No significant associations were observed with neurocognitive functions at age 4.5 years.

CONCLUSION

Our study provides novel data suggesting a potential role of prenatal carotenoids, particularly β-cryptoxanthin, on early offspring cognitive and motor development. Whether the prenatal influences sustain beyond early childhood requires further investigation in longer term studies.

Interventions for increasing fruit and vegetable consumption in children aged five years and under

BACKGROUND

Insufficient consumption of fruits and vegetables in childhood increases the risk of future non-communicable diseases, including cardiovascular disease. Interventions to increase consumption of fruit and vegetables, such as those focused on specific child-feeding strategies and parent nutrition education interventions in early childhood may therefore be an effective strategy in reducing this disease burden.

OBJECTIVES

To assess the effectiveness, cost effectiveness and associated adverse events of interventions designed to increase the consumption of fruit, vegetables or both amongst children aged five years and under.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and two clinical trials registries to identify eligible trials on 25 August 2019. We searched Proquest Dissertations and Theses in May 2019. We reviewed reference lists of included trials and handsearched three international nutrition journals. We contacted authors of included trials to identify further potentially relevant trials.

SELECTION CRITERIA

We included randomised controlled trials, including cluster-randomised controlled trials and cross-over trials, of any intervention primarily targeting consumption of fruit, vegetables or both among children aged five years and under, and incorporating a dietary or biochemical assessment of fruit or vegetable consumption. Two review authors independently screened titles and abstracts of identified papers; a third review author resolved disagreements.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risks of bias of included trials; a third review author resolved disagreements. Due to unexplained heterogeneity, we used random-effects models in meta-analyses for the primary review outcomes where we identified sufficient trials. We calculated standardised mean differences (SMDs) to account for the heterogeneity of fruit and vegetable consumption measures. We conducted assessments of risks of bias and evaluated the quality of evidence (GRADE approach) using Cochrane procedures.

MAIN RESULTS

We included 78 trials with 214 trial arms and 13,746 participants. Forty-eight trials examined the impact of child-feeding practices (e.g. repeated food exposure) in increasing child vegetable intake. Fifteen trials examined the impact of parent nutrition education in increasing child fruit and vegetable intake. Fourteen trials examined the impact of multicomponent interventions (e.g. parent nutrition education and preschool policy changes) in increasing child fruit and vegetable intake. Two trials examined the effect of a nutrition education intervention delivered to children in increasing child fruit and vegetable intake. One trial examined the impact of a child-focused mindfulness intervention in increasing vegetable intake. We judged 20 of the 78 included trials as free from high risks of bias across all domains. Performance, detection and attrition bias were the most common domains judged at high risk of bias for the remaining trials. There is very low-quality evidence that child-feeding practices versus no intervention may have a small positive effect on child vegetable consumption equivalent to an increase of 4.45 g as-desired consumption of vegetables (SMD 0.42, 95% CI 0.23 to 0.60; 18 trials, 2004 participants; mean post-intervention follow-up = 8.2 weeks). Multicomponent interventions versus no intervention has a small effect on child consumption of fruit and vegetables (SMD 0.34, 95% CI 0.10 to 0.57; 9 trials, 3022 participants; moderate-quality evidence; mean post-intervention follow-up = 5.4 weeks), equivalent to an increase of 0.36 cups of fruit and vegetables per day. It is uncertain whether there are any short-term differences in child consumption of fruit and vegetables in meta-analyses of trials examining parent nutrition education versus no intervention (SMD 0.12, 95% CI -0.03 to 0.28; 11 trials, 3078 participants; very low-quality evidence; mean post-intervention follow-up = 13.2 weeks). We were unable to pool child nutrition education interventions in meta-analysis; both trials reported a positive intervention effect on child consumption of fruit and vegetables (low-quality evidence). Very few trials reported long-term effectiveness (6 trials), cost effectiveness (1 trial) and unintended adverse consequences of interventions (2 trials), limiting their assessment. Trials reported receiving governmental or charitable funds, except for four trials reporting industry funding.

AUTHORS' CONCLUSIONS

Despite identifying 78 eligible trials of various intervention approaches, the evidence for how to increase children's fruit and vegetable consumption remains limited. There was very low-quality evidence that child-feeding practice may lead to, and moderate-quality evidence that multicomponent interventions probably lead to small increases in fruit and vegetable consumption in children aged five years and younger. It is uncertain whether parent nutrition education interventions are effective in increasing fruit and vegetable consumption in children aged five years and younger. Given that the quality of the evidence is very low or low, future research will likely change estimates and conclusions. Long-term follow-up of at least 12 months is required and future research should adopt more rigorous methods to advance the field. This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Impact of an early childhood intervention on the home environment, and subsequent effects on child cognitive and emotional development: A secondary analysis

The objective of this study was to use secondary data from the Preparing for Life (PFL) trial to test (1) the impact of a prenatal-to-age-five intervention targeting women from a disadvantaged Irish community on the quality of the home environment; (2) whether any identified changes in the home environment explain the positive effects of the PFL program on children’s cognitive and emotional development at school entry which have been identified in previous reports of the PFL trial (ES = .72 and .50, respectively). Pregnant women were randomized into a treatment (home visits, baby massage, and parenting program, n = 115) or control (n = 118) group (trial registration: ISRCTN04631728). The home environment was assessed at 6 months, 1½, and 3 years using the Home Observation for Measurement of the Environment (responsiveness, acceptance, organization, learning material, involvement, variety). Cognitive skills were assessed at 5 years using the British Ability Scales. Emotional problems were teacher-reported at 5 years using the Short Early Development Inventory. Latent growth modeling was used to model changes in the home environment, and mediation analyses to test whether those changes explained children outcomes. Compared to controls, treatment children were exposed to more stimulating environments in terms of learning material (B = -1.62, p = 0.036) and environmental variety (B = -1.58, p = 0.009) at 6 months, but these differences faded at 3 years. Treatment families were also more likely to accept suboptimal child behaviors without using punishment (acceptance score, B = 1.49, p = 0.048) and were more organized at 3 years (B = 1.08, p = 0.033). None of the changes mediated children’s outcomes. In conclusion, we found that the program positively impacted different home environment dimensions, but these changes did not account for improvements in children’s outcomes. Exploratory analyses suggest that the impact of improvements in the home environment on child outcomes may be limited to specific groups of children. Limitations of the study include the potential lack of generalizability to other populations, the inability to assess the individual treatment components, and sample size restrictions which precluded a moderated mediation analysis.

Interventions Aimed at Increasing Dairy and/or Calcium Consumption of Preschool-Aged Children: A Systematic Literature Review

Dairy product consumption is important during childhood, as dairy products provide nutrients to support growth and development. However, a high proportion of children globally are not meeting recommended daily intakes, which may have long-term health implications. Accumulating evidence suggests that interventions aimed at instilling healthy lifestyle habits are most effective when initiated during the preschool years. Therefore, the purpose of the review was to identify the characteristics of effective dairy and/or calcium interventions targeting preschool-aged children. A systematic literature review identified 14 intervention studies published between 1998⁻2018 addressing dairy/calcium intakes in the preschool population (1.5 to 5 years). Intervention reporting was assessed using intervention intensity, behavior change techniques and Workgroup for Intervention Development and Evaluation Research (WIDER), with the quality of studies evaluated using risk of bias and Grades of Recommendation, Assessment, Development and Evaluation (GRADE). Five of the 14 studies included in the review reported significant improvements in children's dairy (4/5) or calcium (1/5) intake. Characteristics that may enable intervention effectiveness include the delivery of interventions in one setting (preschool facility), using specific behavior change techniques (environmental restructuring and teach to use prompts/cues), and targeting both parent and child. Overall, the interventions assessed demonstrated variable success and highlighted the need for developing effective interventions designed to increase dairy and/or calcium intakes in preschool-aged children.

Interventions for increasing fruit and vegetable consumption in children aged five years and under

BACKGROUND

Insufficient consumption of fruits and vegetables in childhood increases the risk of future non-communicable diseases, including cardiovascular disease. Interventions to increase consumption of fruit and vegetables, such as those focused on specific child-feeding strategies and parent nutrition education interventions in early childhood may therefore be an effective strategy in reducing this disease burden.

OBJECTIVES

To assess the effectiveness, cost effectiveness and associated adverse events of interventions designed to increase the consumption of fruit, vegetables or both amongst children aged five years and under.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and two clinical trials registries to identify eligible trials on 25 January 2018. We searched Proquest Dissertations and Theses in November 2017. We reviewed reference lists of included trials and handsearched three international nutrition journals. We contacted authors of included studies to identify further potentially relevant trials.

SELECTION CRITERIA

We included randomised controlled trials, including cluster-randomised controlled trials and cross-over trials, of any intervention primarily targeting consumption of fruit, vegetables or both among children aged five years and under, and incorporating a dietary or biochemical assessment of fruit or vegetable consumption. Two review authors independently screened titles and abstracts of identified papers; a third review author resolved disagreements.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risks of bias of included studies; a third review author resolved disagreements. Due to unexplained heterogeneity, we used random-effects models in meta-analyses for the primary review outcomes where we identified sufficient trials. We calculated standardised mean differences (SMDs) to account for the heterogeneity of fruit and vegetable consumption measures. We conducted assessments of risks of bias and evaluated the quality of evidence (GRADE approach) using Cochrane procedures.

MAIN RESULTS

We included 63 trials with 178 trial arms and 11,698 participants. Thirty-nine trials examined the impact of child-feeding practices (e.g. repeated food exposure) in increasing child vegetable intake. Fourteen trials examined the impact of parent nutrition education in increasing child fruit and vegetable intake. Nine studies examined the impact of multicomponent interventions (e.g. parent nutrition education and preschool policy changes) in increasing child fruit and vegetable intake. One study examined the effect of a nutrition education intervention delivered to children in increasing child fruit and vegetable intake.We judged 14 of the 63 included trials as free from high risks of bias across all domains; performance, detection and attrition bias were the most common domains judged at high risk of bias for the remaining studies.There is very low quality evidence that child-feeding practices versus no intervention may have a small positive effect on child vegetable consumption equivalent to an increase of 3.50 g as-desired consumption of vegetables (SMD 0.33, 95% CI 0.13 to 0.54; participants = 1741; studies = 13). Multicomponent interventions versus no intervention may have a very small effect on child consumption of fruit and vegetables (SMD 0.35, 95% CI 0.04 to 0.66; participants = 2009; studies = 5; low-quality evidence), equivalent to an increase of 0.37 cups of fruit and vegetables per day. It is uncertain whether there are any short-term differences in child consumption of fruit and vegetables in meta-analyses of trials examining parent nutrition education versus no intervention (SMD 0.12, 95% CI -0.03 to 0.28; participants = 3078; studies = 11; very low-quality evidence).Insufficient data were available to assess long-term effectiveness, cost effectiveness and unintended adverse consequences of interventions. Studies reported receiving governmental or charitable funds, except for four studies reporting industry funding.

AUTHORS' CONCLUSIONS

Despite identifying 63 eligible trials of various intervention approaches, the evidence for how to increase children's fruit and vegetable consumption remains limited. There was very low- and low-quality evidence respectively that child-feeding practice and multicomponent interventions may lead to very small increases in fruit and vegetable consumption in children aged five years and younger. It is uncertain whether parent nutrition education interventions are effective in increasing fruit and vegetable consumption in children aged five years and younger. Given that the quality of the evidence is very low or low, future research will likely change estimates and conclusions. Long-term follow-up is required and future research should adopt more rigorous methods to advance the field.This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

A Multicomponent Early Intervention Program and Trajectories of Behavior, Cognition, and Health

OBJECTIVES

To investigate the developmental impact of a prenatal-to-age-5 multicomponent early intervention program targeting families living in low socioeconomic conditions.

METHODS

Pregnant women from a disadvantaged Irish community were randomly assigned into a treatment group (home visits, baby massage, and parenting program; n = 115) or control group (n = 118). Children's behavioral problems (externalizing, internalizing), cognitive skills (general, vocabulary), and health service use (number of health clinic visits), were regularly assessed (6 months to 4 years of age). Children's developmental trajectories were modeled by using latent class growth analyses to test whether certain subgroups benefited more than others.

RESULTS

High and low developmental trajectories were identified for each outcome. Treated children were more likely to follow the high-level trajectory for cognition (odds ratio = 2.89; 95% confidence interval = 1.55-5.50) and vocabulary skills (odds ratio = 2.02; 95% confidence interval = 1.08-3.82). There were no differences by treatment condition in the risk of belonging to a high externalizing or high health clinic visit trajectory. However, within the high externalizing trajectory, treated children had lower scores than controls (Hedges' g range (2-4 years) = 0.45-0.58; P < .05) and, within the high health clinic visit trajectory, only children in the control group experienced an increasing number of visits.

CONCLUSIONS

This program revealed moderate positive impacts on trajectories of cognitive development and number of health clinic visits for all children, whereas positive impacts on externalizing behavior problems were restricted to children with the most severe problems.

Interventions for increasing fruit and vegetable consumption in children aged five years and under

BACKGROUND

Insufficient consumption of fruits and vegetables in childhood increases the risk of future chronic diseases, including cardiovascular disease.

OBJECTIVES

To assess the effectiveness, cost effectiveness and associated adverse events of interventions designed to increase the consumption of fruit, vegetables or both amongst children aged five years and under.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE and Embase to identify eligible trials on 25 September 2017. We searched Proquest Dissertations and Theses and two clinical trial registers in November 2017. We reviewed reference lists of included trials and handsearched three international nutrition journals. We contacted authors of included studies to identify further potentially relevant trials.

SELECTION CRITERIA

We included randomised controlled trials, including cluster-randomised controlled trials and cross-over trials, of any intervention primarily targeting consumption of fruit, vegetables or both among children aged five years and under, and incorporating a dietary or biochemical assessment of fruit or vegetable consumption. Two review authors independently screened titles and abstracts of identified papers; a third review author resolved disagreements.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risks of bias of included studies; a third review author resolved disagreements. Due to unexplained heterogeneity, we used random-effects models in meta-analyses for the primary review outcomes where we identified sufficient trials. We calculated standardised mean differences (SMDs) to account for the heterogeneity of fruit and vegetable consumption measures. We conducted assessments of risks of bias and evaluated the quality of evidence (GRADE approach) using Cochrane procedures.

MAIN RESULTS

We included 55 trials with 154 trial arms and 11,108 participants. Thirty-three trials examined the impact of child-feeding practices (e.g. repeated food exposure) in increasing child vegetable intake. Thirteen trials examined the impact of parent nutrition education in increasing child fruit and vegetable intake. Eight studies examined the impact of multicomponent interventions (e.g. parent nutrition education and preschool policy changes) in increasing child fruit and vegetable intake. One study examined the effect of a nutrition intervention delivered to children in increasing child fruit and vegetable intake.We judged 14 of the 55 included trials as free from high risks of bias across all domains; performance, detection and attrition bias were the most common domains judged at high risk of bias for the remaining studies.Meta-analysis of trials examining child-feeding practices versus no intervention revealed a positive effect on child vegetable consumption (SMD 0.38, 95% confidence interval (CI) 0.15 to 0.61; n = 1509; 11 studies; very low-quality evidence), equivalent to a mean difference of 4.03 g of vegetables. There were no short-term differences in child consumption of fruit and vegetables in meta-analyses of trials examining parent nutrition education versus no intervention (SMD 0.11, 95% CI -0.05 to 0.28; n = 3023; 10 studies; very low-quality evidence) or multicomponent interventions versus no intervention (SMD 0.28, 95% CI -0.06 to 0.63; n = 1861; 4 studies; very low-quality evidence).Insufficient data were available to assess long-term effectiveness, cost effectiveness and unintended adverse consequences of interventions. Studies reported receiving governmental or charitable funds, except for three studies reporting industry funding.

AUTHORS' CONCLUSIONS

Despite identifying 55 eligible trials of various intervention approaches, the evidence for how to increase children's fruit and vegetable consumption remains sparse. There was very low-quality evidence that child-feeding practice interventions are effective in increasing vegetable consumption in children aged five years and younger, however the effect size was very small and long-term follow-up is required. There was very low-quality evidence that parent nutrition education and multicomponent interventions are not effective in increasing fruit and vegetable consumption in children aged five years and younger. All findings should be considered with caution, given most included trials could not be combined in meta-analyses. Given the very low-quality evidence, future research will very likely change estimates and conclusions. Such research should adopt more rigorous methods to advance the field.This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.