Table 2.

Studies on diet and cognitive development.

Reference	Study design/country	Characteristics of study	Diet measure	Outcome measure	Main results
Feinstein et al. (2008)	Longitudinal cohort study: ALSPACa. England.	•N = 5741 •51% female •94% white	•Dietary patterns created from FFQb data at 38 months, 54 months and 81 months using factor analysis	•Measured between age 10 & 11 •School Attainment, measured using Key Stages standards •Used KS2c for English, Math and Science	•Junk food dietary pattern at age 3 associated with lower results on KS2. •Health conscious pattern at age 3 associated with higher results on KS2. •Only the effect of the junk food pattern remained significant after adjusting for confounding variables.
Gale et al. (2009)	Longitudinal cohort study, the Southampton Women's Survey. England.	•N = 241 •46% female •No race or ethnicity information	•Dietary patterns created from FFQ data at 6 and 12 months using PCAd	•Measured at age 4 •Wechsler Pre-School and Primary Scale of Intelligence test •Measure of FSIQe, VIQf, and PIQg •Developmental Neuropsychological Assessment •Measure of attention, sensorimotor ability, memory, and language •Test of Visual-Perceptual Skills •Measure of visual perception	•Infant guidelines pattern, described as a pattern that “conforms to feeding guidelines as recommended in infant feeding manuals”, at 6 months associated with increases in FSIQ and VIQ. •Borderline significant positive association between the infant guidelines pattern at 6 months and sentence repetition scores. •All other associations were not significant.
Golley et al. (2013)	Longitudinal cohort study: ALSPAC. England.	•N = 4429 •Subsample with maternal IQ N = 1776 •50% female •No race or ethnicity information	•Dietary intake at 6 months via caregiver completed questionnaire •Created CFUIh as a measure of diet quality	•Measured at age 8 •WISCi Version III •Measure of FSIQ, VIQ, and PIQ	•CFUI score was positively associated with FSIQ, VIQ, and PIQ. •Upon adjusting for maternal IQ, relationship between CFUI and FSIQ and VIQ remained significant. •All other associations were not significant.
Northstone et al. (2012)	Longitudinal cohort study: ALSPAC. England.	•Overall cohort N = 6944 •47% female •No race or ethnicity information •Complete data available for N = 3966	•Dietary patterns created from FFQ data at 3, 4, 7, and 8.5 years using PCA	•Measured at age 8.5 •IQj assessed using WISC Version III •Tested picture completion, information, arithmetic, vocabulary, comprehension, and picture arrangement	•Processed food pattern at age 3 associated with a decrease in IQ. •Health-conscious pattern at age 8.5 years associated with increase in IQ. •Snack pattern at age 3 associated with an increase in IQ.
Nyaradi et al. (2013)	Longitudinal cohort study: Raine cohort. Australia.	•N = 1346 for PPVT IIIk measure •49% female •N = 1455 for Raven's Colored Matrices •48% female •No race or ethnicity information	•EATl diet score developed using 24-h recall data at ages 1,2, and 3 •EAT score based on Dietary Guidelines for Children and Adolescents in Australia •Includes 7 food categories: whole grains, vegetables, fruits, meat ratio, dairy, snack foods, sweetened beverages	•Measured at age 10 •PPVT III •Measure of receptive vocabulary and verbal ability •Raven's Colored Progressive Matrices •Measure of nonverbal reasoning ability	•EAT score at age 1 associated with higher PPVT III and nonverbal cognitive ability. Dairy consumption at ages 2 and 3 positively associated with verbal cognitive outcomes. •Higher intake of sugar-sweetened beverages negatively associated with nonverbal reasoning ability.
Smithers, et al. (2012)	Longitudinal cohort study: ALSPAC. England.	•N = 1366 •49% female •97% white	•Dietary patterns created from FFQ data at 6, 15, and 24 months using PCA	•Measured at age 8 •WISC Version III •Measure of FSIQ, VIQ, and PIQ	•Nutrient-dense dietary patterns associated with increases in FSIQ and VIQ and discretionary patterns associated with decreases in FSIQ and VIQ. •At 6 and 15 months, ready-prepared baby foods associated with decreases in FSIQ and VIQ. •At 24 months, ready-to-eat dietary pattern associated with increases in FSIQ and VIQ. •All other associations were not significant.
Smithers et al. (2013)	Longitudinal cohort study: ALSPAC. England.	•N = 7652 •50% female •96% white	•Dietary pattern trajectories created from FFQ data at 6, 15, and 24 months using PCA	•Measured at age 8 and 15 •WISC Version III at age 8 •Measure of FSIQ, VIQ, and PIQ •Abbreviated version of the Weschler Abbreviated Scale of Intelligence at age 15 •Tested vocabulary and matrix reasoning •Measure of IQ	•Healthy dietary pattern trajectory was weakly associated with higher IQ at age 8 but not age 15. •Discretionary and Traditional trajectories were associated with lower IQ at age 15 but not age 8. •The Ready-to-eat trajectory had no association with IQ at either age.
von Stumm et al. (2012)	Longitudinal birth cohort study: The Growing Up in Scotland study. Scotland.	•At baseline, N = 5217 •49% female •At age 3, N = 4193 •At age 5, N = 3833 •No race or ethnicity information	•Frequency of type of children's main meal type per week, defined as fast or slow food. •Fast food: frozen/ready prepared, take away meal, fast-food meal •Slow food: sit down restaurant, or meal with fresh ingredients •Obtained through parent interviews	•Measured at age 3 and 5 •British Ability Scales II which includes Naming Vocabulary and Picture Similarities tests •Measure of expressive language ability and non-verbal reasoning	•Meal types at age 3 positively associated with vocabulary and picture test performance at age 3 and with vocabulary test performance at age 5. •Meal types at age 5 positively associated with cognitive performance at age 5. •Type of meals partially mediated the effects of socioeconomic status on cognitive performance at age 3 and 5. •Having more slow meals was positively associated with changes in vocabulary at ages 3 and 5.

^aAvon Longitudinal Study of Parents and Children.

^bFood Frequency Questionnaire.

^cKey Stage 2.

^dPrincipal Component Analysis.

^eFull Scale Intelligence Quotient.

^fVerbal Intelligence Quotient.

^gPerformance Intelligence Quotient.

^hComplementary Feeding Utility Index.

ⁱWechsler Intelligence Scale for Children.

^jIntelligence Quotient.

^kPeabody Picture Vocabulary Test.

^lEating Assessment in Toddlers.