Associations between obesity and cognition in the pre-school years

The objective was to test the hypothesis that obesity is associated with impaired cognitive outcomes in the pre-school years. Associations were examined between weight status at age 3-5 years and cognitive performance at age 5 years. Cognitive outcome measures were tests of Pattern Construction (visuo-spatial skills), Naming Vocabulary (expressive language skills), and Picture Similarity (reasoning skills). The sample was the UK Millennium Cohort Study (MCS; n 12,349 participants). Boys with obesity at 3 years had significantly lower performance in Pattern Construction at age 5 years compared to those of a healthy weight, even after controlling for confounders (β= -0.029, p=0.03). Controlling for confounders, boys who developed obesity between the age of 3 and 5 years had lower scores in Pattern Construction (β=-0.03, p=0.03). ’Growing out’ of obesity had a beneficial impact on Picture Similarity performance in girls (β=0.03, p=0.04). Obesity in the pre-school years was associated with poorer outcomes for some cognitive measures in this study. Stronger relationships between obesity and cognition or educational attainment may emerge later in childhood.