Childhood diet and behavioural problems: results from the ALSPAC cohort.

Objective: To investigate whether a 'junk food' diet at 81 months of age is associated with the development of behavioural problems over the following 16 months.

Subjects/methods: The study used data from the Avon Longitudinal Study of Parents and Children (ALSPAC) and 12,942 children were included. The main outcome measure was behavioural problems, measured using the Strengths and Difficulties Questionnaire (SDQ). SDQ scores were available at 81 and 97 months of age. Child-based dietary data were collected at 81 months by food frequency questionnaire; from this a 'junk food' score was derived, and mean weekly non-milk extrinsic sugar (NMES) intake estimated. Statistical analyses examined the associations between dietary exposures at 81 months and SDQ outcomes at 97 months. Children with SDQ scores suggesting behavioural problems at baseline were excluded in order to identify new cases. Adjustments were made for potential confounders such as socioeconomic status.

Results: Unadjusted analyses suggested associations between the 'junk food' score at 81 months and both total difficulties and pro-social behaviour at 97 months. However, adjustment for baseline SDQ scores attenuated these associations, with confidence intervals including the null for both total difficulties (OR (95% CI): 1.05 (0.92, 1.21); P=0.45) and pro-social behaviour (1.13 (1.00, 1.26); P=0.04). Adjustment for other potential confounders further attenuated the effects. Adjustment for confounders similarly attenuated modest associations between NMES intake and behavioural problems.

Conclusions: There was no evidence to support an association between a 'junk food' diet at 81 months of age and behavioural problems after 16 months.