Diet and performance

This study (2019) assessing the association between dietary intake and academic achievement among Australian university students conducted online surveys to determine diet quality (through the validated Australian Eating Survey Food Frequency Questionnaire) and academic achievement (as self-reported grade point average[GPA]) and explored their relationship using linear regression while adjusting for socio-demographic and student characteristics. Among the sample population (278 students from University of Newcastle, Australia; mean age 26.9; 70.9% female) a positive correlation was found between GPA and diet quality [in terms of Australian Recommended Food Score (ARFS)], in addition to statistically significant associations between higher subscale scores for vegetables and fruits with lower percentage energy daily from energy-dense nutrient-poor (EDNP) foods overall and also from sweetened drinks. Whatnall et. al note that although the associations between a healthier dietary consumption with greater academic accomplishment, and the vice-versa, are small it can provide students with more motivation to better their dietary habits.

To study the relationship between test anxiety, scholastic performance and dietary intake in rural and urban adolescents, multiple choice tests, anthropometry, test anxiety (TA) demographic questionnaires, and 24 hour diet recall and scholastic performance (SP) from school records were utilised and analysed statistically (2019). The findings included significantly higher MCQ scores seen in favour of those adolescents living in urban areas (69% for boys; 80% for girls) compared to rural boys and girls (41%, 29% respectively) (p>0.05), although the mean TA scores for both sets of adolescents were similar. The data identified a significant negative association between TA levels in urban children with scholastic performance (for both final year marks and for the MCQs), as well as a positive association between TA levels in urban adolescents with junk food consumption (statistically insignificant). Interestingly, junk food consumption was linked with lower SP in the same set of adolescents (p=0.012). When looking at regression analysis results, both TA and junk food intake were negatively correlated to SP (statistically significant again, p=0.04) albeit only in urban children; no such association was determined in the rural subgroup. This study highlights the interrelationships that exist between test anxiety, scholar performance, and junk food intake, raising further awareness of the need for nutritional health programs among these young populations.

Although evidence associates scholastic performance with quality of eating habits, information on this topic is limited in Turkey, which is why Kristo and her group (2020) conducted this study involving students aged 14-17 from 29 different cities in Turkey to evaluate the impact of eating habits quality of high-school students in Turkey on the Scholastic Aptitude Standardised Examination (TEOG) scores. A dietary habits survey was developed, validated and distributed online, Eating Habits Score (EHS) was calculated using a validated scoring system, and Family Affluence Score (FAS) was used to categorise the students by financial standing (low, medium, high). Based on the data of 298 participants, a significant positive correlation was identified between EHS, FAS, and success rate of the students (as indicated by TEOG scores). The researchers state the need for more research in this subject, especially observational studies, to determine appropriate strategies and policies aimed at improving nutritional habit, scholastic performance and general health.

This study (2019) examined the relationships between intake of healthy (fruits, vegetables, unsweetened beverages) and less healthy (sweet and salty snacks, sugar-sweetened beverages) food groups, cognitive performance and academic achievement in a diverse sample of schoolchildren (n=868, 8-10 years old; 56.7% girls; 33.2% non-Hispanic white, 26.2% Hispanic, 17.1% multiracial/other, 8.3% non-Hispanic black; 40.5% overweight/obese). The study used a food frequency questionnaire to report consumption of healthy and unhealthy food groups, Digit Span and Stroop test scores to assess cognitive performance, and finally academic achievement was determined by standardised test scores. Potential confounders (age, sex, body mass index (BMI) z-score, race/ethnicity, English language learner status, individualized education plan enrollment, physical activity, and parent education level) were tested for inclusion in all models. Although there were no statistically significant associations between diet and cognitive test scores, there were strong links between consumption of certain food groups and academic scores - intake of sweet and salty snacks, sweetened beverages was negatively associated with math (OR=0.91; p<0.014) and English standardised test scores (OR=0.87;p=0.001). Sweet snacks and fruit were also negatively associated with English scores (OR=0.72; p=0.003). These associations between unhealthy food group consumption with poorer academic achievement prove that if policies were to be put in place to target these dietary components, this may have a beneficial effect on child academic achievement and development.

Although there is evidence that a healthy diet and being regularly physically active are related with multiple health benefits, there is limited information on the academic and cognitive implications of these behaviors within adolescents, which is the reason Chacon-Cuberos et. al (2018) conducted this cross-sectional study involving 1059 adolescents from Spain. The main instruments employed were the Adherence to Mediterranean Diet Test (KIDMED), the Physical Activity Questionnaire for Adolescents (PAQ-A) and the Motivation and Learning Strategies Short Form (MSLQ-SF). There was a correlation between practising physical activity for >3 hours a week with better dietary habits (p<0.001) such as higher consumption of fish, vegetables, cereals, and nuts. Practising physical activity every week was related to improvements in several of the measured variables and to lower levels of anxiety within the academic environment (p<0.05). The team also discovered adherence to the Mediterranean diet (MD) was positively associated with elaboration and organisational strategies, critical thinking, self-regulation, time and study habits, self-regulation of effort, and intrinsically oriented goals (all p-values <0.01). Given the benefits of eating habits and the practice of PA in the cognitive processes involved in adolescent learning as shown by this study, intervention programs aimed at enhancing healthy habits are recommended.

This 2020 review provides an overview of the associations between health behaviors, cognition and academic achievement in children and adolescents under 18 years of age with a special focus on diet quality. Naveed et. al (2020) state that low consumptions of fish, fruits, vegetables and high intake of fast foods, sausages and soft drinks have been linked to poor cognition and academic accomplishment. There are limited studies on the association between high intake of saturated fat and red meat and low consumption of fiber and higher-fibre grain products with cognition, while the available evidence suggests that diet may have direct, indirect and synergistic effects on the brain and cognition with physical activity, sedentary behaviors, cardiometabolic health, and sleep (although associations have been modest). It can be deduced that a healthy diet, physically active lifestyle, and adequate sleep may provide optimal conditions for brain development and learning. The conclusion drawn by this review is that most of the existing literature is in the form of cross-sectional studies, highlighting the sparsity and need for longitudinal and intervention studies on the impacts of diet, physical activity, sedentary behavior and sleep on cognition and academic achievement.

Burrows and colleagues (2017) combed through seven databases to provide a systematic review of the current literature on the effects of dietary intake and behaviors on the academic achievement of school-aged children. Of the forty studies included, 33 were of cross-sectional design and involved children over the age of 10, with very few reports of younger age groups. In addition, 30 different dietary assessments were used across the studies, with only 40% using a validated or standardised assessment method. With regards to outcomes of academic achievement, half was collected objectively from a recognised educational authority, whereas 10 studies used self-reported measures. The dietary outcomes most commonly reported to have positive associations with academic achievement were: breakfast consumption (n = 12) and global diet quality/meal patterns (n = 7), whereas negative associations reported with junk/fast food (n = 9). Looking at the current literature, the reviewers conclude that moderate associations exist for dietary intakes characterised by regular breakfast consumption, lower intake of energy-dense, nutrient-poor foods and overall diet quality with respect to outcomes of academic achievement, and that utilisation of validated dietary assessment methods and standardised reporting of academic achievement should be considered by future studies.

Four big online scientific databases were searched in this review to provide an evaluation of the impact of healthy dietary consumption on executive functioning among children and adolescents (aged 6-18). Among the studies examining food quality (n=9) or macronutrients (n=4), studies looking at longer-term diet (n=6) demonstrated positive associations between healthier overall diet quality and executive functioning, whereas when the acute effects of diet (n=6) were analysed there was an inconsistency although beneficial impact of higher food quality on executive functioning was suggested. Among the studies examining foods, a positive association could be identified between healthier foods (whole grains, fish, fruit and/or vegetables) and executive functioning, whereas less-healthy snack foods, sugar-sweetened beverages and red or processed meats were inversely associated with executive functioning. Cohen et. al (2016) concludes that evidence suggests healthy dietary intake can be positively associated with executive function, although further studies examining the effects of healthier food consumptions and macronutrients are encouraged yet while they should be ideally conducted in controlled environments and use validated cognitive tests.

Since adherence to the Mediterranean Diet (MD) may enhance academic performance, quality of life as well as mental and physical health in university students, this 2020 review aimed to critically analyse the current evidence with respect to epidemiology (study of distribution and determinants) of MD adherence in university students by comprehensively searching through the PubMed database. Students’ dietary habits are moving away from MD guidelines and more towards unhealthy eating patterns especially in those who live away from home and even those students with a Mediterranean country origin. There are many studies that have documented the association between lower MD adherence and poorer health status, and beneficial effects of higher adherence to MD, which correlates with lower depression risk. The majority of students, even from medical and nutritional university departments, showed a lack of knowledge on healthy eating habits, plus even when students had access to information and knowledge provided by courses and lectures compliance to MD did not increase. Antonopoulou and co. (2020) point out the importance of redirecting research focus on this topic, in order to contribute to improvements in diet, quality of life, mental and physical health of students.

A cross-sectional observational study investigating forty U.S. colleges and universities on the associations between academic performance with moderate-vigorous physical activity, strength training, fruit and vegetable intake, and sleep. The 16,095 undergraduate students (18-24 years; 70.3% female) that took part in the study self-reported lifestyle variables from the NCHA-II questions, which were then deemed to have either met or not met public health recommendations. The following public health recommendations were met in order of incidence: moderate - vigorous physical activity (41.9%); strength training (32.4%); sleep (23.6%); and fruit and vegetable intake (4.6%). Grade average (ranging from 1-4 points) was higher in students meeting moderate-vigorous physical activity (by 0.03 points), fruit and vegetable consumption (by 0.15 points), and sleep recommendations (by 0.06 points). With the exception of strength training recommendations, which did not significantly affect grade average, it can be concluded that college students who adhere to public health recommendations for lifestyle behaviors have modestly greater grade averages in the U.S.

This 2019 thematic review aimed to provide an overview of the current knowledge of the connection between the lifestyle factors diet, physical activity and sleep hygiene with cognition and learning in children. There are cells or animal research available which suggest a number of possible physiological pathways, however, there was a significant gap in knowledge on lifestyle factors and optimal learning in children. Jirout et. al (2019) highlight that 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. While there is focus on childcare and school feeding policies, this review aims to call attention to how child development could be supported using a more holistic approach.

Nutritional quality of diet and academic performance in Chilean students

The Influence of adherence to the Mediterranean diet on academic performance is mediated by sleep quality in adolescents

Dietary changes and its psychosocial moderators during the university examination period

Dietary quality linkage to overall competence at school and emotional disturbance in representative Taiwanese young adolescents: dependence on gender, parental characteristics and personal behaviors

Dietary habits are associated with school performance in adolescents

Associations between selected dietary behaviours and Academic achievement: a study of Australian school aged children

Dietary patterns and school performance: evidence from a sample of adolescents in Sicily, Italy

The relationship between unhealthy snacking at school and academic outcomes: a population study in Chilean school children

The apples of academic performance: associations between dietary patterns and academic performance in Australian children

Is academic achievement related to Mediterranean Diet, substance use and social-cognitive factors: Findings from Lebanese adolescents

The influence of adherence to the Mediterranean diet on academic performance is mediated by sleep quality in adolescents

Relationships between dietary habits and the prevalence of fatigue in medical students