Consumption of a mid-morning snack improves memory but not attention in school children

Impacts of school feeding on educational and health outcomes of school-age children and adolescents in low- and middle-income countries: A systematic review and meta-analysis

Background

School feeding programs are ubiquitous in low- and middle-income countries (LMICs) and may have critical implications for the health and education of school-age children and adolescents. This systematic review aimed to assess the impacts of school feeding on educational and health outcomes of children and adolescents in LMICs.

Methods

Interventional studies on the effects of school feeding on nutritional and health outcomes of children and adolescents receiving primary or secondary education in LMICs were included. MEDLINE, EMBASE, CINAHL, the Cochrane Library, and grey literature were searched (through December 2019) to identify eligible studies. We included randomized controlled trials and controlled before-after studies on school feeding conducted in LMICs among children and adolescents aged 6 to 19 who received primary or secondary education. Two reviewers independently conducted study selection, data extraction, and risk of bias assessment. Meta-analyses were performed for outcomes available in three or more independent studies. Subgroup analyses were conducted by study design and school feeding modality whenever possible.

Results

Fifty-seven articles met the inclusion criteria for the review, including 44 randomized controlled trials and 13 controlled before-after studies; 19 articles were included in the meta-analysis. School feeding resulted in a significant increase in height (mean difference = 0.32 cm; confidence interval (CI) = 0.03, 0.61; P = 0.032) and weight (mean difference: 0.58 kg; 95% 95% CI = 0.22, 0.93; P = 0.001) over 12 months, compared to those in the control groups. School feeding also resulted in a significant increase in the percentage of school days attended (2.6%; 95% CI = 1.2%, 3.9%; P < 0.001).

Conclusions

School feeding is an important approach to improving the health and education outcomes of children and adolescents living in LMICs. More well-designed research is needed to establish further the effectiveness of school feeding for nutritional outcomes and academic achievement.

Registration

PROSPERO ID: CRD42020159003.

The Effects of Magnesium Supplementation on Subjective Anxiety and Stress-A Systematic Review

BACKGROUND

Anxiety related conditions are the most common affective disorders present in the general population with a lifetime prevalence of over 15%. Magnesium (Mg) status is associated with subjective anxiety, leading to the proposition that Mg supplementation may attenuate anxiety symptoms. This systematic review examines the available evidence for the efficacy of Mg supplementation in the alleviation of subjective measures of anxiety and stress.

METHODS

A systematic search of interventions with Mg alone or in combination (up to 5 additional ingredients) was performed in May 2016. Ovid Medline, PsychInfo, Embase, CINAHL and Cochrane databases were searched using equivalent search terms. A grey literature review of relevant sources was also undertaken.

RESULTS

18 studies were included in the review. All reviewed studies recruited samples based upon an existing vulnerability to anxiety: mildly anxious, premenstrual syndrome (PMS), postpartum status, and hypertension. Four/eight studies in anxious samples, four/seven studies in PMS samples, and one/two studies in hypertensive samples reported positive effects of Mg on subjective anxiety outcomes. Mg had no effect on postpartum anxiety. No study administered a validated measure of subjective stress as an outcome.

CONCLUSIONS

Existing evidence is suggestive of a beneficial effect of Mg on subjective anxiety in anxiety vulnerable samples. However, the quality of the existing evidence is poor. Well-designed randomised controlled trials are required to further confirm the efficacy of Mg supplementation.

Methodological Challenges in Studies Examining the Effects of Breakfast on Cognitive Performance and Appetite in Children and Adolescents

Breakfast is purported to confer a number of benefits on diet quality, health, appetite regulation, and cognitive performance. However, new evidence has challenged the long-held belief that breakfast is the most important meal of the day. This review aims to provide a comprehensive discussion of the key methodological challenges and considerations in studies assessing the effect of breakfast on cognitive performance and appetite control, along with recommendations for future research. This review focuses on the myriad challenges involved in studying children and adolescents specifically. Key methodological challenges and considerations include study design and location, sampling and sample section, choice of objective cognitive tests, choice of objective and subjective appetite measures, merits of providing a fixed breakfast compared with ad libitum, assessment and definition of habitual breakfast consumption, transparency of treatment condition, difficulty of isolating the direct effects of breakfast consumption, untangling acute and chronic effects, and influence of confounding variables. These methodological challenges have hampered a clear substantiation of the potential positive effects of breakfast on cognition and appetite control and contributed to the debate questioning the notion that breakfast is the most important meal of the day.

The Effects of Breakfast and Breakfast Composition on Cognition in Children and Adolescents: A Systematic Review

Breakfast is thought to be beneficial for cognitive and academic performance in school children. However, breakfast is the most frequently skipped meal, especially among adolescents. The aim of the current article was to systematically review the evidence from intervention studies for the effects of breakfast on cognitive performance in children and adolescents. The effects of breakfast were evaluated by cognitive domain and breakfast manipulation. A total of 45 studies reported in 43 articles were included in the review. Most studies considered the acute effect of a single breakfast (n = 34). The acute studies looked at breakfast compared with no breakfast (n = 24) and/or comparisons of breakfast type (n = 15). The effects of chronic school breakfast program interventions were evaluated in 11 studies. The findings suggest that breakfast consumption relative to fasting has a short-term (same morning) positive domain-specific effect on cognition. Tasks requiring attention, executive function, and memory were facilitated more reliably by breakfast consumption relative to fasting, with effects more apparent in undernourished children. Firm conclusions cannot be made about the acute effects of breakfast composition and the effects of chronic breakfast interventions because there are too few studies and these largely report inconsistent findings. This review also highlights methodologic limitations of the existing research. These include a lack of research on adolescents, few naturalistic breakfast manipulations or testing environments, small samples, and insensitive cognitive tests.

The effects of a mid-morning snack and moderate-intensity exercise on acute appetite and energy intake in 12-14-year-old adolescents

Energy intake (EI) and energy expenditure (EE) should not be considered independent entities, but more an inter-connected system. With increased physical activity and reduced snacking initiatives as prevalent Public Health measures, any changes to subsequent EI from these recommendations should be monitored. The aim of this study was to investigate changes in acute EI and appetite over four conditions: (1) a control condition with no snack and no exercise (CON); (2) a snack condition (+1 MJ; SK); (3) a moderate-intensity cycling exercise condition (-1 MJ; EX); and finally (4) both snack and exercise condition (+1 MJ, -1 MJ; EXSK). Acute changes in appetite (visual analogue scale) and lunchtime EI (ad libitum pizza meal) were recorded in twenty boys and eighteen girls (12-13 years). Lunch EI was not significantly different between conditions or sexes (P>0·05). Relative EI was calculated, where the energy manipulation (+1 MJ from the snack or -1 MJ from the exercise) was added to lunchtime EI. Relative EI indicated no significant differences between the sexes (P>0·05); however, in the EX condition, relative EI was significantly lower (P<0·001) compared with all other conditions. Appetite increased significantly over time (P<0·001) and was significantly higher in the CON and EX conditions compared with the SK and EXSK conditions. No significant sex differences were found between conditions. When aiming to evoke an acute energy deficit, increasing EE created a significantly larger relative energy deficit than the removal of the mid-morning snack. Sex was not a confounder to influence EI or appetite between any of the conditions.

Early-stage primary school children attending a school in the Malawian School Feeding Program (SFP) have better reversal learning and lean muscle mass growth than those attending a non-SFP school

In developing countries, schoolchildren encounter a number of challenges, including failure to complete school, poor health and nutrition, and poor academic performance. Implementation of school feeding programs (SFPs) in less developed countries is increasing and yet there is mixed evidence regarding their positive effects on nutrition, education, and cognition at the population level. This study evaluated cognitive and anthropometric outcomes in entry-level primary school children in Malawi with the aim of generating evidence for the ongoing debate about SFPs in Malawi and other developing countries. A total of 226 schoolchildren aged 6-8 y in 2 rural Malawian public primary schools were followed for one school year. Children attending one school (SFP school) received a daily ration of corn-soy blend porridge, while those attending the other (non-SFP school) did not. Baseline and post-baseline outcomes included the Cambridge Neurological Test Automated Battery cognitive tests of paired associate learning, rapid visual information processing and intra-extra dimensional shift, and anthropometric measurements of weight, height, and mid-upper arm circumference (MUAC). At follow-up, the SFP subcohort had a greater reduction than the non-SFP subcohort in the number of intra-extra predimensional shift errors made (mean 18.5 and 24.9, respectively; P-interaction = 0.02) and also showed an increase in MUAC (from 16.3 to 17.0; P-interaction <0.0001). The results indicate that the SFP in Malawi is associated with an improvement in reversal learning and catch-up growth in lean muscle mass in children in the SFP school compared with children in the non-SFP school. These findings suggest that the Malawian SFP, if well managed and ration sizes are sustained, may have the potential to improve nutritional and cognitive indicators of the most disadvantaged children.

Multiple micronutrient-fortified rice affects physical performance and plasma vitamin B-12 and homocysteine concentrations of Indian school children

Fortifying rice with multiple micronutrients could be a promising strategy for combat micronutrient deficiencies in developing countries. We determined the efficacy of extruded rice grains fortified with multiple micronutrients on the prevalence of anemia, micronutrient status, and physical and cognitive performance in 6- to 12-y-old, low-income school children in Bangalore, India. In a randomized, double-blind, controlled trial, 258 children were assigned to 1 of 3 intervention groups to receive rice-based lunch meals fortified with multiple micronutrients with either low-iron (6.25 mg) or high-iron (12.5 mg) concentrations or identical meals with unfortified rice. The meals were provided 6 d/wk for 6 mo. Anthropometric, biochemical, physical performance, and cognitive assessments were taken at baseline and endpoint. At baseline, study groups were comparable, with 61% of the children being anemic. However, only <10% were deficient in iron, vitamin A, and zinc. After 6 mo, plasma vitamin B-12 and homocysteine concentrations (both P < 0.001) as well as physical performance (P < 0.05) significantly improved in the intervention arms. No between-group differences were observed in hemoglobin concentration, anemia, and deficiencies of other micronutrients or cognitive function after 6 mo, but paired analyses revealed a small reduction in anemia prevalence in children in the low-iron group. The fortified rice was efficacious in improving vitamin B-12 status and physical performance in Indian school children.

A systematic review of the effect of breakfast on the cognitive performance of children and adolescents

Breakfast is recommended as part of a healthy diet because it is associated with healthier macro- and micronutrient intakes, BMI and lifestyle. Breakfast is also widely promoted to improve cognitive function and academic performance, leading to the provision of breakfast initiatives by public health bodies. Despite this positive and intuitive perception of cognitive benefits, there has been no systematic review of the evidence. Systematic review methodology was employed to evaluate the effects of breakfast on cognitive performance in well-nourished children and nutritionally at-risk or stunted children. Acute experimental studies, school feeding programmes and studies of habitual breakfast intake are reviewed. Comparisons of breakfast v. no breakfast and breakfasts differing in energy and macronutrient composition are discussed. Included are forty-five studies described in forty-one papers published between 1950 and 2008. The evidence indicates that breakfast consumption is more beneficial than skipping breakfast, but this effect is more apparent in children whose nutritional status is compromised. There is a lack of research comparing breakfast type, precluding recommendations for the size and composition of an optimal breakfast for children's cognitive function. Few studies examined adolescents. Studies of school breakfast programmes suggest that such interventions can have positive effects on academic performance, but this may be in part explained by the increased school attendance that programmes encourage. The present systematic review considers methodological issues in this field and makes recommendations for future research design and policy priorities.

Breakfast: a good habit, not a repetitive custom

In developed countries, obesity is the most frequent nutritional disorder, and overweight and obesity prevalences have increased whilst physical activity and breakfast consumption have declined. There is growing scientific interest in the possible role of breakfast in weight control and in factors such as appetite control, dietary quality and reduced risk for chronic diseases. The current article reviews the literature and discusses how the breakfast 'environment' and the composition of breakfast meals might be improved, particularly in children, so as to maintain the breakfast eating habit throughout life. Recommendations are proposed to encourage children to keep eating breakfast and the nutritional composition of the 'American breakfast' and two types of Mediterranean 'cereal breakfasts' are compared. We also propose a new breakfast type for children and adolescents that is based on chocolate hazelnut spread within a mixed breakfast type in order to reinforce positive experiences.