Impact of Early‐Life Weight on Cognitive Abilities in Children
A developing child’s mind is highly sensitive to environmental factors and it is now well known that overweight and obesity has a significant impact on the metabolic and endocrine profile of an individual. This new study, published in Obesity, sets sets out to try and determine if childhood obesity has any effect on cognitive ability, guided by the hypothesis that the production of adipocytokines and inflammatory molecules may adversely affect neurodevelopment.
The study included 233 children, who underwent measurements of weight and height to formulate a WHZ score, in the first two years of life. Then through ages 5 to 8 years, the children underwent a comprehensive assessment of cognitive abilities, including attention, impulsivity, working memory and reference memory.
Their findings suggest that early high WHZ, may be inversely associated with full scale IQ, perceptual reasoning index and working memory index, after adjusting for potential confounders. It also found slower reaction time and lower continuous performance test scores. The other cognitive tests conducted did not find an association with early-life WHZ.
The strength of this study is that it used prospective data which enabled them to investigate weight status in the first 2 years of life, which are critical to brain development. This allowed for better understanding of the direction of the association. Furthermore the cognitive tests were repeatedly administered by professionals, and encompassed a comprehensive array of cognitive abilities, which previous studies had not done. FInally they also accounted for covariates, such as socioeconomic status, perinatal factors and maternal IQ.
From this they are able to conclude that early-life obesity seems to affect full scale IQ, perceptual reasoning and working memory scores (boys only), as well as increasing reaction times among school aged children. More research needs to be conducted to confirm these findings, and the authors suggest also measuring school performance, ADHD diagnosis, learning disabilities or special education service use.