Breakfast glycaemic index and cognitive function in adolescent school children

Modifiable factors influencing attention performance in healthy children: insights from a comprehensive school nutrition study

BACKGROUND

There is inconclusive evidence for the effects of various leisure activities on attention performance in children. The literature reports inconsistent associations between activities such as physical activities or media use. To date, no study has thoroughly examined the various factors influencing attentional performance in a larger cohort of healthy children. This study aims to close this research gap.

METHODS

From 2018 to 2019, the Leipzig School Nutrition Study collected data from 1215 children and their families. The children report their dietary behavior (using CoCu- Questionnaire), especially their participation in school lunch and their breakfast habits, through a paper questionnaire. Furthermore, attention performance was assessed using a validated test (FAIR-2) at school. Data on physical activity, media consumption, family eating habits and socio-economic status (SES) were collected from parents using questionnaires. Associations between attention and influencing factors were estimated using hierarchical linear regression. Analyses were adjusted for age, SES, and school type.

RESULTS

Attending upper secondary schools (ßadj= 23.6, p < 0.001) and having a higher SES (ß= 1.28, p < 0.001) was associated with higher attention performance. Children doing leisure-time sports (ßadj= 4.18, p = 0.046) or reading books for at least one hour/weekday showed better attention performance (ßadj= 3.8, p = 0.040). Attention performance was also better in children having no electronic devices in the bedroom (ßadj= 13.0, p = 0.005) and in children whose parents limited their children's Internet access (ßadj= 5.2, p = 0.012). We did not find any association between nutritional habits and attention performance.

CONCLUSIONS

We found that fostering modifiable habits such as reading and physical activity could enhance attention performance. These findings have substantial implications for the development of prevention and intervention programs that aim to improve attention in schoolchildren. It is important to note, however, that social status as a hardly modifiable factor also impacts attention performance. Therefore, interventions should address personal habits in a systemic approach considering the child's social status.

TRIAL REGISTRATION

The study is retrospectively registered with the German Clinical Trials Register (DRKS00017317, registration: 05-29-2019).

A healthy breakfast each and every day is important for students' motivation and achievement

Breakfast is often cited as the most important meal of the day and vital for students' academic functioning at school. Although much research has linked students' breakfast consumption to better achievement, there has been debate about why and how breakfast has academic benefits. The present study of 648 Australian high school students investigated (a) the role of breakfast consumption and breakfast quality in students' self-reported motivation and their achievement in a science test, (b) the role of motivation in mediating the link between breakfast consumption and quality and students' achievement, and (c) the extent to which breakfast consumption effects are moderated by the quality of breakfast (e.g., more vegetables, fruit, dairy/protein, wholegrains, cereals, water; less sugary drinks, processed meat, fast take-away, unhealthy snack foods). Findings indicated that beyond the effects of personal, home, and classroom factors, breakfast consumption predicted higher adaptive motivation (p < .05), breakfast quality predicted lower maladaptive motivation (p < .05), and in turn, students' adaptive (positively, p < .01) and maladaptive (negatively, p < .01) motivation predicted their achievement. Moreover, adaptive motivation significantly mediated the relationship between breakfast consumption and achievement (p < .05). The effect of breakfast consumption was moderated by the quality of breakfast such that consuming a high-quality breakfast in the morning was associated with the highest levels of adaptive motivation (p < .01) and achievement (p < .05) later in the day. Findings have implications for educational practice and policy seeking to promote a healthy start to the school day to optimize students' motivation and achievement.

Executive function during exercise is diminished by prolonged cognitive effort in men

The speed and accuracy of decision-making (i.e., executive function (EF) domains) is an integral factor in many sports. At rest, prolonged cognitive load (pCL) impairs reaction time (RT). In contrast, exercise improves RT and EF. We hypothesized that RT and EF during exercise would be diminished by prolonged 'dual tasking' as a consequence of pCL. To test the hypothesis, twenty healthy male participants performed four conditions [resting control (Rest), pCL only (pCL_Rest), exercise only (EX), and pCL + exercise (pCL_EX)] in a randomized-crossover design. Both exercise conditions utilized a 50-min cycling exercise protocol (60% VO₂ peak) and the pCL was achieved via a 50-min colour-word Stroop task (CWST). Compared with Rest, pCL_Rest caused a slowed CWST RT (P < 0.05) and a large SD (i.e., intraindividual variability) of CWST RT (P < 0.01). Similarly, compared with EX, the slowed CWST RT (P < 0.05) and large SD of CWST RT (P < 0.01) were also observed in pCL_EX. Whereas the reverse-Stroop interference was not affected in pCL_Rest (P = 0.46), it was larger (i.e., declined EF) in pCL_EX than EX condition (P < 0.05). These observations provide evidence that the effort of pCL impairs RT and EF even during exercise.

The impact of glycaemic load on cognitive performance: A meta-analysis and guiding principles for future research

The effect of breakfast glycaemic load (GL) on cognition was systematically examined. Randomised and non-randomised controlled trials were identified using PubMed, Scopus, and Cochrane Library (up to May 2022). 15 studies involving adults (aged 20 - 80 years) were included. Studies had a low risk, or some concerns, of bias. A random-effects meta-analysis model revealed no effect of GL on cognition up to 119 min post-consumption. However, after 120 min, immediate episodic memory scores were better following a low-GL compared to a high-GL (SMD = 0.16, 95% confidence interval [CI] = -0.00 to 0.32, p = 0.05, I2 = 5%). Subgroup analyses indicated that the benefit was greater in younger adults (<35 years) and those with better GT. A qualitative synthesis of 16 studies involving children and adolescents (aged 5 - 17 years) suggested that a low-GL breakfast may also benefit episodic memory and attention after 120 min. Methodological practises were identified which could explain a failure to detect benefits in some studies. Consequently, guiding principles were developed to optimise future study design.

A Study on Legume-Based Noodles as Staple Food for Office Workers

This study aims to verify the effects of “legume-based noodles” as a staple food for lunch, specifically: blood glucose, cognitive function tests, Kansei value, work questionnaires, typing, and body weight. The experiment is divided into two groups: the intervention group (legumes-based noodle) and the control group (regular lunch). Both groups have similar menu except the staple food. The intervention group resulted in a statistically significant lower blood glucose area under the curve (AUC) and lower maximum blood glucose levels during the afternoon work hours on weekdays. In addition, the Kansei value “concentration” decreased at the end of the workday in the control group compared to before and after lunch but did not decrease in the intervention group. Furthermore, the number of typing accuracy was higher in the intervention group than in the control group, and the questionnaire responses for “work efficiency” and “motivation” were more positive. These results suggest that eating legume-based noodles may lead to improved performance of office workers.

Physical fitness, physical activity and adiposity: associations with risk factors for cardiometabolic disease and cognitive function across adolescence

BACKGROUND

The cross-sectional associations between physical activity, physical fitness and adiposity with risk factors for cardiometabolic disease (particularly novel ones such as inflammatory cytokines) and cognitive function across the period of adolescence are not well understood. Additionally, novel physical activity metrics that summarise activity volume and intensity in a continuous manner have not been investigated in this context. Therefore, this study investigated the cross-sectional associations between physical activity, physical fitness and adiposity with risk factors for cardiometabolic disease and cognitive function. These associations were compared between younger and older adolescents.

METHODS

Seventy younger (11-12y, 35 girls) and 43 older (14-15y, 27 girls) adolescents volunteered to take part in the study. Physical fitness (multi-stage fitness test, MSFT) and adiposity (waist circumference) were determined, followed 7d later by resting blood pressure, a fasted blood sample (glucose, plasma insulin, IL6, IL10, IL15 and IL-1β concentrations) and a cognitive function test battery. Habitual physical activity was monitored via hip-worn accelerometers over this 7-d period and the average acceleration (activity volume), and intensity gradient (intensity distribution of activity) were determined.

RESULTS

Average acceleration and intensity gradient were negatively associated with mean arterial blood pressure (β = -0.75 mmHg, p = 0.021; β = -10 mmHg, p = 0.006, respectively), and waist circumference was positively associated with IL-6 concentration (β = 0.03%, p = 0.026), with stronger associations observed in older adolescents. Higher physical fitness (MSFT distance) was positively associated with anti-inflammatory IL-15 concentration (β = 0.03%, p = 0.038) and faster response times on the incongruent Stroop task (β = -1.43 ms, p = 0.025), the one-item level of the Sternberg paradigm (β = -0.66 ms, p = 0.026) and the simple (β = 0.43 ms, p = 0.032) and complex (β = -2.43 ms, p = 0.020) levels of the visual search test, but these were not moderated by age group.

CONCLUSIONS

The present study highlights the important role of physical activity (both the volume and intensity distribution) and physical fitness for cardio-metabolic health. Furthermore, the present study highlights the importance of physical fitness for a variety of cognitive function domains in adolescents, irrespective of age.

Nutritional Impact on Metabolic Homeostasis and Brain Health

Aging in modern societies is often associated with various diseases including metabolic and neurodegenerative disorders. In recent years, researchers have shown that both dysfunctions are related to each other. Although the relationship is not fully understood, recent evidence indicate that metabolic control plays a determinant role in neural defects onset. Indeed, energy balance dysregulation affects neuroenergetics by altering energy supply and thus neuronal activity. Consistently, different diets to help control body weight, blood glucose or insulin sensitivity are also effective in improving neurodegenerative disorders, dampening symptoms, or decreasing the risk of disease onset. Moreover, adapted nutritional recommendations improve learning, memory, and mood in healthy subjects as well. Interestingly, adjusted carbohydrate content of meals is the most efficient for both brain function and metabolic regulation improvement. Notably, documented neurological disorders impacted by specific diets suggest that the processes involved are inflammation, mitochondrial function and redox balance as well as ATP production. Interestingly, processes involving inflammation, mitochondrial function and redox balance as well as ATP production are also described in brain regulation of energy homeostasis. Therefore, it is likely that changes in brain function induced by diets can affect brain control of energy homeostasis and other brain functions such as memory, anxiety, social behavior, or motor skills. Moreover, a defect in energy supply could participate to the development of neurodegenerative disorders. Among the possible processes involved, the role of ketone bodies metabolism, neurogenesis and synaptic plasticity, oxidative stress and inflammation or epigenetic regulations as well as gut-brain axis and SCFA have been proposed in the literature. Therefore, the goal of this review is to provide hints about how nutritional studies could help to better understand the tight relationship between metabolic balance, brain activity and aging. Altogether, diets that help maintaining a metabolic balance could be key to both maintain energy homeostasis and prevent neurological disorders, thus contributing to promote healthy aging.

Impact of lunch with carbohydrates differing in glycemic index on children's cognitive functioning in the late postprandial phase: a randomized crossover study

Purpose

Studies about effects of lunch dietary Glycemic Index (GI) on cognition of schoolchildren are scarce. Our previous CogniDo GI study found no changes of cognition in the early postprandial phase after consumption of two rice types with medium vs. high dietary GI for lunch (i.e., 45 min after starting lunch). This study investigated whether the dietary GI of lunch has an impact on cognition of schoolchildren in the late postprandial phase, 90 min after lunch.

Methods

A randomized, 2 × 2 crossover intervention study was conducted at a comprehensive school with 5th and 6th grade students. Participants (n = 212) were randomly assigned to either sequence 1 or 2. In the first period, participants of sequence 1 received a dish with high GI rice (GI: 79), those of sequence 2 with medium GI rice (GI: 64)—in the second period, 1 week later, vice versa. Computer-based cognitive testing was performed 90 min after lunch examining tonic alertness, visual search and task switching, and working memory. Treatment effects and treatment effects adjusted for estimated lunch glycemic load (GL) were analyzed using a linear mixed model.

Results

The selected cognitive parameters were not affected by the GI of lunch 90 min after lunch, neither after intention-to-treat nor in the per-protocol analysis. Adjustment for GL also did not change results.

Conclusion

The present study revealed no notable differences after the consumption of two rice types with medium vs. high dietary GI for lunch in children’s cognitive function in the late postprandial phase, 90 min after lunch.

Clinical trial registration

German Clinical Trials Register (DRKS00013597); date of registration: 16/04/2018, retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02766-y.

Effect of Differing Durations of High-Intensity Intermittent Activity on Cognitive Function in Adolescents

Exercise duration may influence the acute effects on cognition. However, only one study to date has explored the dose-response relationship between exercise duration and cognition in adolescents. Thus, the purpose of this study was to investigate the effect of differing durations of high-intensity intermittent running on cognition in adolescents. Thirty-eight adolescents (23 girls) completed three trials separated by 7 d: 30 min exercise, 60 min exercise, and rest; in a randomised crossover design. The exercise was a modified version of the Loughborough Intermittent Shuttle Test (LIST), which elicited high-intensity intermittent exercise. Cognitive function tests (Stroop test, Sternberg paradigm, Flanker task) were completed 30 min pre, immediately post, and 45 min post exercise. Response times on the incongruent level of the Flanker task improved to a greater extent 45 min following the 30 min LIST, compared to rest (p = 0.009). Moreover, response times improved to a greater extent on the three-item level of Sternberg paradigm 45 min following the 30 min LIST, compared to the 60 min LIST (p = 0.002) and rest (p = 0.013), as well as on the five-item level 45 min following the 30 min LIST, compared to the 60 min LIST (p = 0.002). In conclusion, acute exercise enhanced subsequent cognition in adolescents, but overall, 30 min of high-intensity intermittent running is more favourable to adolescents' cognition, compared to 60 min.

Changes in Learning Outcomes after Dietary Intervention in Preschoolers: A Pilot Study

The executive functioning skill set, which includes working memory, cognitive flexibility, and inhibitory control, begins developing in early life and continues into adulthood. Preschoolers' abilities to perform those skills may be influenced by diet. The purpose of this study was to explore the acute effects of consuming a low-GI diet compared to the usual childcare diet on preschoolers' self-reported feelings of hunger and fullness and their performance on learning-associated tasks. This study was a prospective feeding trial in n = 20 children 3-4 years of age, completed in a laboratory setting where children attended "day camps" and consumed two days of usual diet (CON) and two days of low-GI (INT) diet. Learning outcomes were evaluated using select learning assessments including the Kansas Reflection-Impulsivity Scale for Preschoolers (KRISP), Track-it, Peg Tapping, and Happy/Sad. Repeated measures, full-factorial analysis of covariance revealed that diet was significantly related to impulsivity (p > 0.05), and univariate analysis of variance indicated that feelings of hunger and fullness differentially affected cognitive constructs in that feeling full improved impulsivity and attention, while feeling hungry improved inhibitory control. These findings highlight that the connection between diet and learning-related skills of children are independently mediated by both diet composition and feelings of hunger and fullness.

Breakfast and Exercise Improve Academic and Cognitive Performance in Adolescents

This study examined the combined effects of breakfast and exercise on short-term academic and cognitive performance in adolescents. Eighty-two adolescents (64 female), aged 14–19 years, were randomized to four groups over a 4-hour morning: (i) a group who fasted and were sedentary (F-S); (ii) a group who ate breakfast but were sedentary (B-S); (iii) a group who fasted but completed a 30-min exercise bout (F-E); and (iv) a group who ate breakfast and completed a 30-min exercise bout (B-E). Individuals completed academic and cognitive tests over the morning. Adolescents in B-E significantly improved their mathematics score (B-E: 15.2% improvement on correct answers, vs. F-S: 6.7% improvement on correct answers; p = 0.014) and computation time for correct answers (B-E: 16.7% improvement, vs. F-S: 7.4% improvement; p = 0.004) over the morning compared with the F-S group. The B-E group had faster reaction times for congruent, incongruent and control trials of the Stroop Color-Word Task compared with F-S mid-morning (all p < 0.05). Morning breakfast and exercise combine to improve short-term mathematical task performance and speed in adolescents.

Plasma brain-derived neurotrophic factor and dynamic cerebral autoregulation in acute response to glycemic control following breakfast in young men

We examined the acute impact of both low- and high-glycemic index (GI) breakfasts on plasma brain-derived neurotrophic factor (BDNF) and dynamic cerebral autoregulation (dCA) compared with breakfast omission. Ten healthy men (age 24 ± 1 yr) performed three trials in a randomized crossover order; omission and Low-GI (GI = 40) and High-GI (GI = 71) breakfast conditions. Middle cerebral artery velocity (transcranial Doppler ultrasonography) and arterial pressure (finger photoplethysmography) were continuously measured for 5 min before and 120 min following breakfast consumption to determine dCA using transfer function analysis. After these measurements of dCA, venous blood samples for the assessment of plasma BDNF were obtained. Moreover, blood glucose was measured before breakfast and every 30 min thereafter. The area under the curve of 2 h postprandial blood glucose in the High-GI trial was higher than the Low-GI trial (P < 0.01). The GI of the breakfast did not affect BDNF. In addition, both very-low (VLF) and low-frequency (LF) transfer function phase or gains were not changed during the omission trial. In contrast, LF gain (High-GI P < 0.05) and normalized gain (Low-GI P < 0.05) were decreased by both GI trials, while a decrease in VLF phase was observed in only the High-GI trial (P < 0.05). These findings indicate that breakfast consumption augmented dCA in the LF range but High-GI breakfast attenuated cerebral blood flow regulation against slow change (i.e., the VLF range) in arterial pressure. Thus we propose that breakfast and glycemic control may be an important strategy to optimize cerebrovascular health.

Mens Sana in Corpore Sano: Does the Glycemic Index Have a Role to Play?

Although diet interventions are mostly related to metabolic disorders, nowadays they are used in a wide variety of pathologies. From diabetes and obesity to cardiovascular diseases, to cancer or neurological disorders and stroke, nutritional recommendations are applied to almost all diseases. Among such disorders, metabolic disturbances and brain function and/or diseases have recently been shown to be linked. Indeed, numerous neurological functions are often associated with perturbations of whole-body energy homeostasis. In this regard, specific diets are used in various neurological conditions, such as epilepsy, stroke, or seizure recovery. In addition, Alzheimer’s disease and Autism Spectrum Disorders are also considered to be putatively improved by diet interventions. Glycemic index diets are a novel developed indicator expected to anticipate the changes in blood glucose induced by specific foods and how they can affect various physiological functions. Several results have provided indications of the efficiency of low-glycemic index diets in weight management and insulin sensitivity, but also cognitive function, epilepsy treatment, stroke, and neurodegenerative diseases. Overall, studies involving the glycemic index can provide new insights into the relationship between energy homeostasis regulation and brain function or related disorders. Therefore, in this review, we will summarize the main evidence on glycemic index involvement in brain mechanisms of energy homeostasis regulation.

Cognitive performance, mood and satiety following ingestion of beverages imparting different glycaemic responses: a randomised double-blind crossover trial

BACKGROUND/OBJECTIVE

The relationship between postprandial glycaemic responses and cognitive performance, mood and satiety are inconsistent. The objective of this study is to compare the effects of different glycaemic responses, induced by beverages with different glycaemic index (GI) (sucrose and isomaltulose), and a non-glycaemic control (sucralose), on cognition, mood and satiety.

SUBJECTS/METHODS

In this double-blinded, randomised crossover trial, healthy adults (n = 55) received sucrose (GI 65), isomaltulose (GI 32) and sucralose (non-caloric negative control) drinks on separate occasions. The Complex Figure test, the Word Recall test, Trail Making Test Part B and the Stroop test were administered 60 min after beverages ingestion. Mood and satiety were tested along with cognitive performance.

RESULTS

Comparing between isomaltulose and sucrose, there were no significant differences in the mean (95% CI) for the following: Complex Figure: immediate recall -0.6 (-1.7, 0.5), delayed recall -0.8 (-1.9, 0.3); Word recall: immediate recall 0.2 (-0.7, 1.1), delayed recall 0.5 (-0.4, 1.4); Trail Making: completing time -2.4 (-7.5, 2.7) s; Stroop: time used for correct congruent responses -9 (-31, 14) ms and correct incongruent responses -18 (-42, 6) ms. No differences among beverages were found in the mood and satiety scores with exception that participants felt more energetic 60 min after isomaltulose ingestion (p = 0.028 for difference with sucrose) and hungrier 30 min after isomaltulose ingestion (p = 0.036 for difference with sucrose; p = 0.022 for difference with sucralose).

CONCLUSION

Under these study conditions there is no convincing evidence for an effect of glycaemic response on cognitive performance, mood or satiety.

Effect of football activity and physical fitness on information processing, inhibitory control and working memory in adolescents

Background

Whilst an acute bout of exercise has been shown to enhance subsequent cognition, including in adolescents, the effects of team games (of which Football is the most popular) has received little attention. Therefore, this study examined: the effect of an acute bout of outdoor Football activity on information processing, inhibitory control, working memory and circulating brain-derived neurotrophic factor (BDNF) in adolescents; the effect of physical fitness on cognition and; the moderating effect of physical fitness on the acute exercise responses.

Methods

Following familiarisation, 36 adolescents (16 girls) took part in two trials (60-min Football and 60-min seated rest) separated by 7-d in a counterbalanced, crossover design. Information processing and inhibitory control (Stroop Test), and working memory (Sternberg Paradigm) were assessed 30-min before exercise/rest and immediately, 45- and 90-min post-exercise/rest. Capillary blood samples were obtained before exercise/rest and up to 120-min post-exercise/rest. The median split of distance covered on the MSFT was used to divide the group into high- and low-fit groups.

Results

Performance on the cognitive function tasks was similar between Football and seated rest (trial*time interactions; all p > .05). However, the high-fit group had overall quicker response times on both levels of the Stroop Task and all three levels of the Sternberg Paradigm (main effect of fitness; all p < .001). Furthermore, the exercise-cognition relationship was moderated by physical fitness, with improvements in working memory response times seen post-exercise, only in the high-fit group (trial*time*fitness interaction, p < .05). Circulating BDNF was unaffected by the Football activity and physical fitness (p > .05).

Conclusion

The present study shows that higher levels of physical fitness are beneficial for cognitive function and provides novel evidence that an ecologically valid, and popular, form of exercise is beneficial for working memory following exercise, in high-fit participants only.

The prevalence and comorbidity rates of specific learning disorder among primary school children in Turkey

Purpose: The aim of the present study was to investigate the prevalence of specific learning disorder (SLD), comorbid disorders, and risk factors in primary school children for the first time in two-stage design in Turkey.Materials and methods: Participants were 1041 pupils in 28 primary schools and aged from 7 to 11. The Mathematics, Reading, Writing Assessment Scale (MOYA) teacher and parent forms were used in the screening stage and parents and teachers of each child completed MOYA. Ninety-five children were screen positive and eighty-three of these children participated in the interview. SLD diagnoses were based on DSM V criteria. Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL) was used for the comorbid psychiatric disorders.Results and conclusions: The prevalence rate of the SLD was 6.6%, impairment in reading was 4%, in mathematics was 3.6%, and in written expression was 1.8%. About 62.75% of children with SLD had one or more comorbid diagnoses. ADHD was the most common comorbid mental disorder in SLD (54.9%). SLD prevalence was higher among males. The prevalence of SLD in primary school children in Turkey is consistent with previous studies.

Short-term effects of carbohydrates differing in glycemic index (GI) consumed at lunch on children's cognitive function in a randomized crossover study

Background

Intervention studies suggest an influence of breakfast dietary glycemic index (GI) on children’s cognition. The Cognition Intervention Study Dortmund-GI-I study examined whether lunch dietary GI might have short-term effects on selected cognitive parameters.

Methods

A randomized crossover study was performed at a comprehensive school on 2 test days. One hundred and eighty-nine participants (5th and 6th grade) were randomly assigned to one of the two sequences, medium-high GI (m-hGI) or high-medium GI (h-mGI), following block randomization. In the first period, one group received a dish containing hGI rice (GI: 86) ad libitum, the other mGI rice (GI: 62)—1 week later, in the second period, vice versa. Tonic alertness, task switching, and working memory updating were tested with a computerized test battery 45 min after beginning of lunch break. Treatment effects were estimated using the t test for normally distributed data or the Wilcoxon rank-sum test for non-normally distributed data.

Results

The crossover approach revealed no effects of lunch dietary GI on the tested cognitive parameters in the early afternoon. However, we determined carryover effects for two parameters, and therefore analyzed only data of the first period. The reaction time of the two-back task (working memory updating) was faster (p = 0.001) and the count of commission errors in the alertness task was lower (p = 0.04) in the hGI group.

Conclusion

No evidence of short-term effects of lunch dietary GI on cognition of schoolchildren was found. Potential positive effects on single parameters of working memory updating and tonic alertness favoring hGI rice need to be verified.

Effect of Exercise Duration on Postprandial Glycaemic and Insulinaemic Responses in Adolescents

High-intensity intermittent exercise (HIIE) is a potential intervention to manage hyperglycaemia and insulin resistance in adolescents. The aim of this study was to determine the optimum duration of HIIE to reduce postprandial glycaemic and insulinaemic responses in adolescents and the longevity of the response. Thirty-nine participants (12.4 ± 0.4 year) completed a 30- and 60-min exercise trial (Loughborough Intermittent Shuttle Test) and a rested control trial in a randomised crossover design. Capillary blood samples were taken at baseline, immediately and 1-h post-exercise; and 30, 60 and 120 min following a standardised lunch (day one) and a standardised breakfast 24-h post-exercise. Plasma insulin total area under the curve (tAUC) following lunch was lower following 60-min HIIE (21754 ± 16861 pmol·L^-1 × 120 min, p = 0.032) and tended to be lower following 30-min HIIE (24273 ± 16131 pmol·L^-1 × 120 min, p = 0.080), when compared with the resting condition (26931 ± 21634 pmol·L^-1 × 120 min). Blood glucose concentration was lower 1-h post-exercise following 30-min HIIE (3.6 ± 0.6 mmol·L^-1) when compared to resting (4.1 ± 0.9 mmol·L^-1, p = 0.001). Blood glucose and plasma insulin concentration did not differ across trials on day two. Shorter bouts of HIIE (30-min), as well as a 60-min bout, reduced the postprandial insulinaemic response to lunch, an ecologically valid marker of insulin sensitivity. As the beneficial effects of HIIE were limited to 3 h post-exercise, adolescents are recommended to engage daily HIIE to enhance metabolic health.

Associations of dietary carbohydrate and fatty acid intakes with cognition among children

OBJECTIVE

To investigate the cross-sectional associations of dietary carbohydrate and fatty acid intakes with cognition in mid-childhood.

DESIGN

Dietary carbohydrate and fatty acid intakes were assessed using 4-d food records, and cognition was evaluated using the Raven's Coloured Progressive Matrices (RCPM) score. The cross-sectional associations of dietary carbohydrate and fatty acid intakes with cognition were investigated using linear regression analyses adjusted for age, sex, body fat percentage, household income, parental education and daily energy intake.

SETTING

The baseline examinations of the Physical Activity and Nutrition in Children study.

PARTICIPANTS

A population-based sample of 487 children (250 boys, 237 girls) aged 6-8 years living in the city of Kuopio, Finland.

RESULTS

A higher dietary intake of fructose (standardised regression coefficient, β = 0·24, P < 0·001), total fibre (β = 0·16, P = 0·02) and soluble fibre (β = 0·15, P = 0·02) was associated with a higher RCPM score in boys. Other dietary carbohydrates and fatty acids, including total carbohydrates, glucose, sucrose, starch, insoluble fibre, total fat, SFAs, MUFAs, PUFAs, palmitic acid (C16), stearic acid (C18), linoleic acid (C18:2), α-linoleic acid (C18:3), arachidonic acid (C20:4), EPA (C20:5n-3) and DHA (C22:6n-6), were not associated with the RCPM score in boys. Dietary carbohydrates or fatty acids were not associated with the RCPM score in girls.

CONCLUSIONS

Higher dietary fructose and fibre intakes were associated with better cognition in boys, but not in girls. Dietary fatty acids were not related to cognition in boys or in girls.

How Lifestyle Factors Affect Cognitive and Executive Function and the Ability to Learn in Children

In today's research environment, children's diet, physical activity, and other lifestyle factors are commonly studied in the context of health, independent of their effect on cognition and learning. Moreover, there is little overlap between the two literatures, although it is reasonable to expect that the lifestyle factors explored in the health-focused research are intertwined with cognition and learning processes. This thematic review provides an overview of knowledge connecting the selected lifestyle factors of diet, physical activity, and sleep hygiene to children's cognition and learning. Research from studies of diet and nutrition, physical activity and fitness, sleep, and broader influences of cultural and socioeconomic factors related to health and learning, were summarized to offer examples of research that integrate lifestyle factors and cognition with learning. The literature review demonstrates that the associations and causal relationships between these factors are vastly understudied. As a result, current knowledge on predictors of optimal cognition and learning is incomplete, and likely lacks understanding of many critical facts and relationships, their interactions, and the nature of their relationships, such as there being mediating or confounding factors that could provide important knowledge to increase the efficacy of learning-focused interventions. This review provides information focused on studies in children. Although basic research in cells or animal studies are available and indicate a number of possible physiological pathways, inclusion of those data would distract from the fact that there is a significant gap in knowledge on lifestyle factors and optimal learning in children. In a climate where childcare and school feeding policies are continuously discussed, this thematic review aims to provide an impulse for discussion and a call for more holistic approaches to support child development.

Comparative Effect of Low-Glycemic Index versus High-Glycemic Index Breakfasts on Cognitive Function: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aims to compare the effect of High-Glycemic Index (GI) versus Low-GI breakfasts on cognitive functions, including memory and attention, of children and adolescents. We systematically searched the MEDLINE (via PubMed), EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Web of Science databases, from their inception until June 2019. Articles comparing the effect of Low-GI versus High-GI breakfasts on the cognitive function (i.e., immediate memory, delayed memory, and attention) of children and adolescents were included. The DerSimonian and Laird method was used to compute the pooled effect sizes (ESs) and their respective 95% confidence intervals (CIs). The pooled ESs were 0.13 (95% CI: −0.11, 0.37) for immediate memory and 0.07 (95% CI: −0.15, 0.28) for delayed memory. For attention, the pooled ES was −0.01 (95% CI: −0.27, 0.26). In summary, GI breakfasts do not affect cognitive domains in children and adolescents.

Effect of potatoes and other carbohydrate-containing foods on cognitive performance, glycemic response, and satiety in children

Dietary carbohydrates have been shown to influence cognitive performance and satiety in children. However, it remains unclear whether the carbohydrate source is a primary determinant of cognitive performance and satiety. The objective was to compare the effects of white potatoes and other carbohydrate-containing foods on cognitive performance, glycemic response, and satiety in children. On 6 separate mornings, in random order, children (n = 22) consumed 50 g of available carbohydrates from microwaved mashed potatoes (prepared from fresh potatoes then frozen), deep-fried potato strips (French fries), hash browns, white rice, white beans, or skipped a meal. Cognitive performance, glycemic response, and satiety were measured over 180 min. Cognitive performance was measured using a battery of tests assessing verbal declarative memory, spatial memory, short-term memory, working memory, and information processing speed. Although cognitive performance after the treatment meals did not differ from meal skipping, children recalled more words after French fries (9.1 ± 0.4 words) compared with mashed potatoes (8.2 ± 0.3 words; p = 0.001) and white rice (8.4 ± 0.3 words; p = 0.04) on the verbal declarative memory test. Blood glucose concentrations were higher after white rice compared with white beans, mashed potatoes, and hash browns (p < 0.05). Change from baseline subjective average appetite (mm/kcal) was lower after mashed potatoes compared with all other treatment meals (p < 0.05). In conclusion, verbal declarative memory was higher after French fries and subjective average appetite was lower after mashed potatoes. Future longitudinal studies are needed to confirm these short-term findings and to elucidate the mechanism of action.

Cytokine, glycemic, and insulinemic responses to an acute bout of games-based activity in adolescents

An acute bout of endurance exercise in adults stimulates a same‐day anti‐inflammatory response which may affect low‐grade chronic inflammation and insulin resistance and benefit cardio‐metabolic health. The anti‐inflammatory responses to intermittent games‐based exercise and to exercise in young people beyond 2 hours post‐exercise are unknown. Thus, the purpose of the present study is to examine the anti‐inflammatory, glycemic and insulinemic response to games‐based activity in adolescents. Following ethical approval and familiarization, 39 adolescents (12.3 ± 0.7 years) completed an exercise (E) and rested (R) trial in a counterbalanced, randomized crossover design. Following a standardized breakfast, participants completed 1‐hour games‐based activity. Capillary blood samples were taken at baseline, immediately and 1 hour post‐exercise, and 30, 60 and 120 minutes following a standardized lunch. A final blood sample was taken the next morning. Data were analyzed using repeated measures ANOVA. IL‐6 concentration was higher on day one of the exercise trial (E:3.4 ± 0.4, R:2.7 ± 0.4 pg/mL; P = 0.006), as was the anti‐inflammatory IL‐6:TNF‐α ratio (E:5.53 ± 0.93, R:3.75 ± 0.45; P = 0.027). Levels of the anti‐inflammatory cytokine IL‐10 increased on day two of the exercise trial (E:2.11 ± 0.23, R:1.66 ± 0.16 pg/mL; P = 0.032). Insulin sensitivity was enhanced on the exercise trial with a reduction in iAUC following the standardized lunch (E:2310 ± 834, R:3122 ± 1443 mU/L × 120 minutes; P < 0.001). Games‐based activity stimulated an anti‐inflammatory response up to 24 hours post‐exercise and improved insulin sensitivity in response to a standardized meal in healthy adolescents. These novel findings suggest that games‐based activity is an ecologically valid mode of exercise to elicit beneficial effects on cardio‐metabolic risk factors in young people.

Memory and potential correlates among children in Jordan

BACKGROUND

Cognitive functioning hugely affects the performance of tasks of different complexity. Memory, one of the most important cognitive skills, allows children to practice and acquire necessary skills and knowledge and interact with the surrounding environment. Therefore, it is crucial to study the factors that influence the memory of children. The main purpose of his study was to investigate different variables related to memory in school aged children (5-9 years, N = 434).

METHODS

Parents of the participants provided information about child's daily behavior, child's school academic achievement, work and family income data and demographics. Memory skills in children were assessed by using the Leiter International Performance Scale -Revised.

RESULTS

The score of memory increased 2.53 points with upsurge in maternal occupation level, 3.08 points when the child ate breakfast and 4.51 points when the child daily slept nine hours and more. By contrast, increased family income and smoking by father resulted in decreased scores in memory.

CONCLUSION

Screening for and understanding of memory and relevant factors are vital for broad understanding of children's capabilities and weaknesses as well as for developing appropriate interventions.

Obesity and unhealthy lifestyle associated with poor executive function among Malaysian adolescents

The understanding on the roles of obesity and lifestyle behaviors in predicting executive function of adolescents has been limited. Low executive function proficiency may have adverse effects on adolescents’ school academic performance. This cross-sectional study aimed to examine the relationship between BMI-for-age and multiple lifestyle behaviors (operationalized as meal consumption, physical activity, and sleep quality) with executive function (operationalized as inhibition, working memory, and cognitive flexibility) on a sample of Malaysian adolescents aged between 12 and 16 years (N = 513). Participants were recruited from two randomly selected schools in the state of Selangor in Malaysia. Using a self-administered questionnaire, parent participants provided information concerning their sociodemographic data, whereas adolescent participants provided information regarding their meal consumptions, physical activity, and sleep quality. The modified Harvard step test was used to assess adolescents’ aerobic fitness, while Stroop color-word, digit span, and trail-making tests were used to assess adolescents’ inhibition, working memory, and cognitive flexibility, respectively. Three separate hierarchical regression analyses were conducted for each outcome namely, inhibition, working memory, and cognitive flexibility. After adjusted for sociodemographic factors and BMI-for-age, differential predictors of inhibition and working memory were found. Habitual sleep efficiency significantly and positively predicted inhibition. Regular dinner intakes, physical activity levels, and sleep quality significantly and positively predicted working memory. Household income emerged as a consistent predictor for all executive function domains. In conclusion, an increased trend of obesity and unhealthy lifestyles among adolescents were found to be associated with poorer executive function. Regular dinner intakes, higher physical activity levels and better sleep quality predicted better executive function despite the inverse relationship between obesity and executive function. Future studies may explore how lifestyle modifications can optimize the development of executive function in adolescents as well as relieve the burden of obesity.

Acute Post-Prandial Cognitive Effects of Brown Seaweed Extract in Humans

(Poly)phenols and, specifically, phlorotannins present in brown seaweeds have previously been shown to inhibit α-amylase and α-glucosidase, key enzymes involved in the breakdown and intestinal absorption of carbohydrates. Related to this are observations of modulation of post-prandial glycemic response in mice and increased insulin sensitivity in humans when supplemented with seaweed extract. However, no studies to date have explored the effect of seaweed extract on cognition. The current randomized, placebo-controlled, double-blind, parallel groups study examined the impact of a brown seaweed extract on cognitive function post-prandially in 60 healthy adults (N = 30 per group). Computerized measures of episodic memory, attention and subjective state were completed at baseline and 5 times at 40 min intervals over a 3 h period following lunch, with either seaweed or placebo consumed 30 min prior to lunch. Analysis was conducted with linear mixed models controlling for baseline. Seaweed led to significant improvements to accuracy on digit vigilance (p = 0.035) and choice reaction time (p = 0.043) tasks. These findings provide the first evidence for modulation of cognition with seaweed extract. In order to explore the mechanism underlying these effects, future research should examine effects on cognition in parallel with blood glucose and insulin responses.

Breakfast and behavior in morning tasks: Facts or fads?

BACKGROUND

Most of the studies investigating the effects of breakfast on cognitive performance have compared performance in subjects who have or have not consumed this meal. However, characteristics of breakfast itself may influence mental abilities. Moreover, as far as the positive effects of having breakfast is more evident, research may focus on the specific characteristics of an adequate breakfast.

METHODS

To update an existing systematic review, published at the beginning of 2014, on the role of nutrient composition and/or energy intake at breakfast on the accomplishment of school-related tasks and cognition, we carried out a systematic review of the literature through PUBMED database.

RESULTS

From the literature search, we identified 39 papers, of which 2 were eligible according to our inclusion criteria. Both the selected papers concerned randomized crossover studies on the acute effect of breakfast carried out in a school setting in the United Kingdom. Both studies compared 2 iso-energetic breakfasts with a similar macronutrient composition; however, the alternative breakfasts were meant to differ in terms of glycemic index or glycemic load. The effects of breakfast composition were investigated on memory, attention, and information processing in both studies. However, different tests and subdomains were considered.

LIMITATIONS

Studies on these issues are still inconsistent and quantitatively insufficient to draw firm conclusions.

CONCLUSIONS

While the hypothesis of a better mental performance with breakfast>20% daily energy intake still needs confirmation, there does appear to be extra evidence that a lower postprandial glycemic response is beneficial to mental performance.

Energy Balance–Related Behavior and Anthropometric Measures Among Adolescents Across Three Educational Levels: A Cross-Sectional Study in Dutch Schools

Energy balance–related behavior on schooldays and beliefs about school-based interventions may differ between students in different educational levels, sexes, and BMI (body mass index) categories. In Zwolle (the Netherlands), 1,084 adolescents (13-15 years) at 9 secondary schools completed a questionnaire. Overweight prevalence (boys 18.1%, girls 19.3%) increased with decreasing educational level, especially in boys. Girls reported healthier behavior than boys regarding daily consumption of fruit (35% vs. 29%), vegetables (58% vs. 48%), ≤1 snack/candy (36% vs. 26%), ≤3 glasses of sugared drinks (80% vs. 73%; all p < .05). Unhealthier dietary behaviors were associated with lower educational level, except for eating sugary and savory snacks. Snacks and sugared drinks consumed at school were mostly brought from home (61.6% and 68.5%, respectively). Overweight students reported less frequent consumption of daily breakfast, snacks, and sugared drinks than nonoverweight students. Of all students, 40% spent ≥1 hour per day cycling to school. Lower educational level students reported less organized sports activities than higher level students, but more outside play and other activities. Overweight was associated with cycling to school (boys) and participating in organized sports (girls). More girls than boys were interested in lessons about healthy nutrition (44.4% vs. 31.7%). To stimulate physical activity, boys suggested more physical education classes (63%), girls advised more variation (47%) and choice (43%). A healthy school canteen (57%) and offering free fruit (67%) were suggested as promising interventions to stimulate healthy behavior. Educational and environmental interventions to tackle unhealthy dietary and physical activity behavior should be developed in collaboration with parents and tailored to educational level and gender.

The impact of diet-based glycaemic response and glucose regulation on cognition: evidence across the lifespan

The brain has a high metabolic rate and its metabolism is almost entirely restricted to oxidative utilisation of glucose. These factors emphasise the extreme dependence of neural tissue on a stable and adequate supply of glucose. Whereas initially it was thought that only glucose deprivation (i.e. under hypoglycaemic conditions) can affect brain function, it has become apparent that low-level fluctuations in central availability can affect neural and consequently, cognitive performance. In the present paper the impact of diet-based glycaemic response and glucose regulation on cognitive processes across the lifespan will be reviewed. The data suggest that although an acute rise in blood glucose levels has some short-term improvements of cognitive function, a more stable blood glucose profile, which avoids greater peaks and troughs in circulating glucose is associated with better cognitive function and a lower risk of cognitive impairments in the longer term. Therefore, a habitual diet that secures optimal glucose delivery to the brain in the fed and fasting states should be most advantageous for the maintenance of cognitive function. Although the evidence to date is promising, it is insufficient to allow firm and evidence-based nutritional recommendations. The rise in obesity, diabetes and metabolic syndrome in recent years highlights the need for targeted dietary and lifestyle strategies to promote healthy lifestyle and brain function across the lifespan and for future generations. Consequently, there is an urgent need for hypothesis-driven, randomised controlled trials that evaluate the role of different glycaemic manipulations on cognition.

Sex differences in adolescents’ glycaemic and insulinaemic responses to high and low glycaemic index breakfasts: a randomised control trial

During puberty young people undergo significant hormonal changes which affect metabolism and, subsequently, health. Evidence suggests there is a period of transient pubertal insulin resistance, with this effect greater in girls than boys. However, the response to everyday high and low glycaemic index (GI) meals remains unknown. Following ethical approval, forty adolescents consumed a high GI or low GI breakfast, in a randomised cross-over design. Capillary blood samples were taken during a 2-h postprandial period, examining the glycaemic and insulinaemic responses. Maturity offset and homoeostatic model assessment (HOMA) were also calculated. The glycaemic response to the breakfasts was similar between boys and girls, as shown by similar peak blood glucose concentrations and incremental AUC (IAUC) following both high and low GI breakfasts (all P>0·05). Girls exhibited a higher peak plasma insulin concentration 30 min post-breakfast following both high GI (P=0·043, g=0·69) and low GI (P=0·010, g=0·84) breakfasts, as well as a greater IAUC following high GI (P=0·041, g=0·66) and low GI (P=0·041, g=0·66) breakfasts. HOMA was positively correlated with the insulinaemic responses (all P<0·0005) and maturity offset (P=0·037). The findings of the present study suggest that pubertal insulin resistance affects the postprandial insulinaemic responses to both high and low GI meals. Specifically, girls exhibit a greater insulinaemic response than boys to both meals, despite similar glycaemic responses. This study is the first to report the glycaemic and insulinaemic responses to everyday meals in boys and girls, supporting the recommendation for young people to base their diet on low GI carbohydrates.

Satiety and memory enhancing effects of a high-protein meal depend on the source of protein

OBJECTIVE

High- protein diets have become increasingly popular with various touted benefits. However, the extent to which protein quantity and source affects cognitive functioning through altering postprandial amino acid profiles has not been investigated. Further, whether all protein sources are similarly anorexigenic is uncertain. The objective of this study was to determine the influence of protein level and source on Barnes maze performance, satiety and plasma amino acid levels in male Sprague-Dawley rats.

METHODS

Rats were entrained to a meal-feeding schedule consisting of a 30 minutes meal, equivalent to 20% of average daily intake, one hour into the dark phase then ad libitum access to food for 5 h. On test days, rats received one of three isocaloric diets as their first meal, hereafter referred to as Egg White (EW), Wheat Gluten (WG), or Basal, and then were measured for cognitive performance, feeding behavior, or plasma amino acid levels via jugular catheter. Percentage energy from protein was 35% for both EW and WG and 20% for Basal with equal amounts provided by EW and WG proteins.

RESULTS

Rats provided EW performed similarly to Basal on the Barnes maze, whereas WG performed worse. EW increased satiety, whereas WG reduced satiety relative to Basal. Both EW and WG increased postprandial concentrations of large neutral and branched chain amino acids relative to Basal, but in EW, concentrations were slower to peak, and peaked to a higher level than WG.

DISCUSSION

Results demonstrate the importance of protein source for cognition and satiety enhancing effects of a high-protein meal.

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.

Breakfast consumption has no effect on neuropsychological functioning in children: a repeated-measures clinical trial

BACKGROUND

Although many studies have investigated the relation between breakfast consumption and various domains of cognitive functioning within children, some of the reported findings are inconsistent.

OBJECTIVE

We sought to determine the short-term effects of a breakfast meal on the neuropsychological functioning of healthy school-aged children after an overnight fast.

DESIGN

The study was conducted in a clinical research center with the use of a counterbalanced repeated-measures design among children who either consumed breakfast or were fasting. The administered neuropsychological tests included measures of attention, impulsivity, short-term memory, cognitive processing speed, and verbal learning. The sample consisted of children aged 8-10 y (n = 128), of whom 52% were female, 38% were African American, 31% were Hispanic, 28% were white, and 3% were of another race/ethnicity.

RESULTS

There were no significant (P ≥ 0.004) differences between breakfast meal consumption and fasting for any of the neuropsychological measures administered.

CONCLUSION

Breakfast consumption had no short-term effect on neuropsychological functioning in healthy school-aged children. This trial was registered at clinicaltrials.gov as NCT01943604.

The effect of healthy dietary consumption on executive cognitive functioning in children and adolescents: a systematic review

A systematic review was conducted to evaluate whether healthier dietary consumption among children and adolescents impacts executive functioning. PubMed, Education Resources Information Center, PsychINFO and Thomson Reuters’ Web of Science databases were searched, and studies of executive functioning among children or adolescents aged 6–18 years, which examined food quality, macronutrients and/or foods, were included. Study quality was also assessed. In all, twenty-one studies met inclusion criteria. Among the twelve studies examining food quality (n 9) or macronutrient intakes (n 4), studies examining longer-term diet (n 6) showed positive associations between healthier overall diet quality and executive functioning, whereas the studies examining the acute impact of diet (n 6) were inconsistent but suggestive of improvements in executive functioning with better food quality. Among the ten studies examining foods, overall, there was a positive association between healthier foods (e.g. whole grains, fish, fruits and/or vegetables) and executive function, whereas less-healthy snack foods, sugar-sweetened beverages and red/processed meats were inversely associated with executive functioning. Taken together, evidence suggests a positive association between healthy dietary consumption and executive functioning. Additional studies examining the effects of healthier food consumption, as well as macronutrients, on executive functioning are warranted. These studies should ideally be conducted in controlled environments and use validated cognitive tests.

Sprint-based exercise and cognitive function in adolescents

Moderate intensity exercise has been shown to enhance cognition in an adolescent population, yet the effect of high-intensity sprint-based exercise remains unknown and was therefore examined in the present study. Following ethical approval and familiarisation, 44 adolescents (12.6 ± 0.6 y) completed an exercise (E) and resting (R) trial in a counter-balanced, randomised crossover design. The exercise trial comprised of 10 × 10 s running sprints, interspersed by 50 s active recovery (walking). A battery of cognitive function tests (Stroop, Digit Symbol Substitution (DSST) and Corsi blocks tests) were completed 30 min pre-exercise, immediately post-exercise and 45 min post-exercise. Data were analysed using mixed effect models with repeated measures. Response times on the simple level of the Stroop test were significantly quicker 45 min following sprint-based exercise (R: 818 ± 33 ms, E: 772 ± 26 ms; p = 0.027) and response times on the complex level of the Stroop test were quicker immediately following the sprint-based exercise (R: 1095 ± 36 ms, E: 1043 ± 37 ms; p = 0.038), while accuracy was maintained. Sprint-based exercise had no immediate or delayed effects on the number of items recalled on the Corsi blocks test (p = 0.289) or substitutions made during the DSST (p = 0.689). The effect of high intensity sprint-based exercise on adolescents' cognitive function was dependant on the component of cognitive function examined. Executive function was enhanced following exercise, demonstrated by improved response times on the Stroop test, whilst visuo-spatial memory and general psycho-motor speed were unaffected. These data support the inclusion of high-intensity sprint-based exercise for adolescents during the school day to enhance cognition.

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.

Trends from 2002 to 2010 in Daily Breakfast Consumption and its Socio-Demographic Correlates in Adolescents across 31 Countries Participating in the HBSC Study

Breakfast is often considered the most important meal of the day and children and adolescents can benefit from breakfast consumption in several ways. The purpose of the present study was to describe trends in daily breakfast consumption (DBC) among adolescents across 31 countries participating in the HBSC survey between 2002 to 2010 and to identify socio-demographic (gender, family affluence and family structure) correlates of DBC. Cross-sectional surveys including nationally representative samples of 11–15 year olds (n = 455,391). Multilevel logistic regression analyses modeled DBC over time after adjusting for family affluence, family structure and year of survey. In all countries, children in two-parent families were more likely to report DBC compared to single parent families. In most countries (n = 19), DBC was associated with family affluence. Six countries showed an increase in DBC (Canada, Netherland, Macedonia, Scotland, Wales, England) from 2002. A significant decrease in DBC from 2002 was found in 11 countries (Belgium Fr, France, Germany, Croatia, Spain, Poland, Russian Federation, Ukraine, Latvia, Lithuania and Norway), while in 5 countries (Portugal, Denmark, Finland, Ireland, Sweden) no significant changes were seen. Frequency of DBC among adolescents in European countries and North America showed a more uniform pattern in 2010 as compared to patterns in 2002. DBC increased significantly in only six out of 19 countries from 2002 to 2010. There is need for continued education and campaigns to motivate adolescents to consume DBC. Comparing patterns across HBSC countries can make an important contribution to understanding regional /global trends and to monitoring strategies and development of health promotion programs.

Cognitive function at rest and during exercise following breakfast omission

It has been suggested that breakfast omission, as opposed to breakfast consumption, has the detrimental effects on cognitive function. However, the effects of acute exercise following breakfast omission on cognitive function are poorly understood, particularly during exercise. The purpose of this study was to examine the interactive effects of breakfast and exercise on cognitive function. Ten participants completed cognitive tasks at rest and during exercise in the breakfast consumption or omission conditions. Blood glucose concentration was measured immediately after each cognitive task. We used cognitive tasks to assess working memory [Spatial Delayed Response (DR) task] and executive function [Go/No-Go (GNG) task]. The participants cycled ergometer for 30 min while keeping their heart rate at 140 beats·min(-1). Accuracy of the GNG task was lower at rest in the breakfast omission condition than that in the breakfast consumption condition (Go trial: P=0.012; No-Go trial: P=0.028). However, exercise improved accuracy of the Go trial in the breakfast omission condition (P=0.013). Reaction time in the Go trial decreased during exercise relative to rest in both conditions (P=0.002), and the degree of decreases in reaction time was not different between conditions (P=0.448). Exercise and breakfast did not affect the accuracy of the Spatial DR task. The present results indicate that breakfast omission impairs executive function, but acute exercise improved executive function even after breakfast omission. It appears that beneficial effects of acute exercise on cognitive function are intact following breakfast omission.

Breakfast Intake and Composition Is Associated with Superior Academic Achievement in Elementary Schoolchildren

OBJECTIVE

To determine whether breakfast consumption or content affects academic achievement measured by standardized tests.

METHODS

Baseline data were collected in fall of 2011 from 698 students (50.5% female, age = 7.5 ± 0.6 years) living in the state of Kansas. Academic achievement was assessed using 3 components from the Wechsler Individual Achievement Test (WIAT-III). Prior to taking the WIAT-III, participants completed a breakfast recall of all foods and drinks consumed that morning, which was analyzed using Nutrition Data System for Research (NDS-R). WIAT-III scores were compared between breakfast and non-breakfast consumers in a sample (n = 162) matched for age, sex, race, education level of both parents, household income, body mass index (BMI), and cardiovascular fitness, and Pearson correlations were calculated from all breakfast eaters (n = 617) between test performance and components of the breakfast.

RESULTS

When compared to non-breakfast consumers, the breakfast consumers had significantly higher scores in all 3 WIAT-III components (all p < 0.05). In breakfast consumers, servings of fruit juice were negatively correlated with reading comprehension and fluency standard score and mathematics standard score (both p < 0.0001), and greater servings of whole grains were significantly related to higher scores in reading comprehension and fluency and mathematics (both p < 0.05).

CONCLUSION

Both breakfast consumption and the content may be associated with improved standardized test performance in elementary school students.

IV. The cognitive implications of obesity and nutrition in childhood

The prevalence of childhood obesity in the United States has tripled since the 1980s and is strongly linked to the early onset of several metabolic diseases. Recent studies indicate that lower cognitive function may be another complication of childhood obesity. This review considers the research to date on the role of obesity and nutrition on childhood cognition and brain health. Although a handful of studies point to a maladaptive relationship between obesity and aspects of cognitive control, remarkably little is known regarding the impact of fat mass on brain development and cognitive function. Further, missing from the literature is the role of nutrition in the obesity-cognition interaction. Nutrition may directly or indirectly influence cognitive performance via several pathways including provision of key substrates for optimal brain health, modulation of gut microbiota, and alterations in systemic energy balance. However, in the absence of malnutrition, the functional benefits of specific nutrient intake on particular cognitive domains are not well characterized. Here, we examine the literature linking childhood obesity and cognition while considering the effects of nutritional intake. Possible mechanisms for these relationships are discussed and suggestions are made for future study topics. Although childhood obesity prevalence rates in some developed countries have recently stabilized, significant disparities remain among groups based on sex and socioeconomic status. Given that the elevated prevalence of pediatric overweight and obesity may persist for the foreseeable future, it is crucial to develop a comprehensive understanding of the influence of obesity and nutrition on cognition and brain health in the pediatric population.

The effect of breakfast versus no breakfast on brain activity in adolescents when performing cognitive tasks, as assessed by fMRI

OBJECTIVES

The study examined the feasibility of utilizing functional magnetic resonance imaging (fMRI) with a group of adolescent boys and girls to assess modifications in cognitive function, dependent upon the nutritional state of the participants.

METHODS

Twenty children aged 12-14 years completed two cognitive trials, in a randomized counterbalanced order, one under fasting condition, one after consuming breakfast, during which continuous fMRI data were acquired.

RESULTS

Although no statistically significant (P > 0.05) improvement in task performance was determined, significantly higher activation was recorded in the frontal, premotor, and primary visual cortex areas in the breakfast trial relative to the fasting condition.

DISCUSSION

Such a finding may have important implications in the examination of the role of diet, and specifically breakfast, in determining children's performance within the school environment.

Effects of beta-alanine supplementation on brain homocarnosine/carnosine signal and cognitive function: an exploratory study

Objectives

Two independent studies were conducted to examine the effects of 28 d of beta-alanine supplementation at 6.4 g d^-1 on brain homocarnosine/carnosine signal in omnivores and vegetarians (Study 1) and on cognitive function before and after exercise in trained cyclists (Study 2).

Methods

In Study 1, seven healthy vegetarians (3 women and 4 men) and seven age- and sex-matched omnivores undertook a brain 1H-MRS exam at baseline and after beta-alanine supplementation. In study 2, nineteen trained male cyclists completed four 20-Km cycling time trials (two pre supplementation and two post supplementation), with a battery of cognitive function tests (Stroop test, Sternberg paradigm, Rapid Visual Information Processing task) being performed before and after exercise on each occasion.

Results

In Study 1, there were no within-group effects of beta-alanine supplementation on brain homocarnosine/carnosine signal in either vegetarians (p = 0.99) or omnivores (p = 0.27); nor was there any effect when data from both groups were pooled (p = 0.19). Similarly, there was no group by time interaction for brain homocarnosine/carnosine signal (p = 0.27). In study 2, exercise improved cognitive function across all tests (P<0.05), although there was no effect (P>0.05) of beta-alanine supplementation on response times or accuracy for the Stroop test, Sternberg paradigm or RVIP task at rest or after exercise.

Conclusion

28 d of beta-alanine supplementation at 6.4g d^-1 appeared not to influence brain homocarnosine/carnosine signal in either omnivores or vegetarians; nor did it influence cognitive function before or after exercise in trained cyclists.

Breakfast glycaemic index and exercise: combined effects on adolescents' cognition

The aim of the present study was to examine the combined effects of breakfast glycaemic index (GI) and a mid-morning bout of exercise on adolescents' cognitive function. Participants were randomly allocated to a high or low GI breakfast group in a mixed research design, where each participant completed two experimental trials (exercise and resting). Forty-two adolescents (12.4±0.5 years old), undertook a bout of exercise (ten repeats of level one of the multi-stage fitness test; exercise trial) or continued to rest (resting trial) following consumption of either a high or low GI breakfast. A battery of cognitive function tests (visual search test, Stroop test and Sternberg paradigm) was completed 30 min before and 45 min following the exercise. Average heart rate during exercise was 170±15 beats·min(-1). On the complex level of the Stroop test, response times improved across the morning following the low GI breakfast on both the exercise and resting trials, though the improvement was greatest on the exercise trial. However, response times only improved on the resting trial following the high GI breakfast (p=0.012). On the 5 letter level of the Sternberg paradigm, response times improved across the morning following the low GI breakfast (regardless of exercise) and only on the exercise trial following the high GI breakfast (p=0.019). The findings of the present study suggest that the combined effects of breakfast GI and exercise in adolescents depend upon the component of cognitive function examined. A low GI breakfast and mid-morning bout of exercise were individually beneficial for response times on the Sternberg paradigm, whereas they conferred additional benefits for response times on the Stroop test.

The effect of using isomaltulose (Palatinose™) to modulate the glycaemic properties of breakfast on the cognitive performance of children

Purpose

Although previous research has associated the glycaemic load (GL) of a meal with cognitive functioning, typically the macro-nutrient composition of the meals has differed, raising a question as to whether the response was to GL or to the energy, nutrients or particular foods consumed. Therefore, the present study contrasted two breakfasts that offered identical levels of energy and macro-nutrients, although they differed in GL.

Methods

Using a repeated-measures, double-blind design, 75 children aged 5–11 years, from socially deprived backgrounds, attended a school breakfast club and on two occasions, at least a week apart, they consumed a meal sweetened with either isomaltulose (Palatinose™) (GL 31.6) or glucose (GL 59.8). Immediate and delayed verbal memory, spatial memory, sustained attention, reaction times, speed of information processing and mood were assessed 1 and 3 h after eating.

Results

The nature of the meals did not influence any measure of cognition or mood after an hour; however, after 3 h, children’s memory and mood improved after the lower-GL breakfast. If children had eaten the lower-GL meal on the second day of testing, they were able to process information faster and had better spatial memory later in the morning.

Conclusions

Towards the end of a morning in school, having consumed a lower-GL breakfast resulted in better mood and aspects of cognitive functioning.

A low glycaemic load breakfast can attenuate cognitive impairments observed in middle aged obese females with impaired glucose tolerance

BACKGROUND AND AIMS

There has been no systematic investigation of the individual and combined effects of impaired glucose tolerance (IGT) and obesity on cognitive function in the absence of ageing. The aims were to examine the effects of IGT and increased waist circumference on cognitive function in ostensibly healthy adults, and to investigate whether a low glycaemic load (GL) breakfast can attenuate cognitive impairments in these populations.

METHODS AND RESULTS

Sixty five females aged 30-50 years were classified into one of four groups following waist circumference (WC) measurements and an oral glucose tolerance test: NGT/low WC (n = 25), NGT/high WC (n = 22), IGT/low WC (n = 9), IGT/high WC (n = 9). Memory, psychomotor and executive functions were examined 30 and 120 min after consuming low GL, high GL and water breakfasts according to a randomised, crossover, counterbalanced design. IGT was associated with impairment of verbal and spatial memory, and psychomotor function relative to females with NGT, independent of waist circumference. Increased waist circumference was associated with impairment of verbal memory and executive function relative to females with low WC, independent of IGT. Consumption of the LGL breakfast attenuated verbal memory impairment in the IGT/high WC group relative to the HGL breakfast and no energy control.

CONCLUSION

Increased central adiposity and abnormalities in glucose tolerance preceding type 2 diabetes can have demonstrable negative effects on cognitive function, even in ostensibly healthy, middle-aged females. The potential for GL manipulations to modulate glycaemic response and cognitive function in type 2 diabetes and obesity merits further investigation.