Children with attention-deficit/hyperactivity disorder (ADHD) weighed less at birth but were significantly more likely to have obesity after age five compared with those without ADHD, according to a study issued by the Journal of the American Academy of Child & Adolescent Psychiatry. However, elevated ADHD symptoms were not predictive of increased obesity risk until age 7 in females and age 11 in males.
“The relationship between ADHD and body weight, despite being largely investigated, is still unclear,” wrote Claire Reed, M.Sc., of the University of Southampton, and colleagues. “Children with increased ADHD symptoms are typically lighter at birth than their peers but are later more likely to have obesity. Research into the ‘when and why’ regarding this turning point is scarce.”
Reed and colleagues used data from the Millennium Cohort Study, which included 7,908 children born between 2000 and 2002. Families provided data when children were 9 months old and again at ages 3, 5, 7, 11, 14, and 17. The 442 children with ADHD were identified either when they received a diagnosis or by the results of the Strengths and Difficulties Questionnaire (SDQ) hyperactivity/inattention subscale. Parents completed the SDQ during each data collection wave between the ages of 3 and 17. Children who scored high or very high on the subscale during at least five of the six waves were considered to have ADHD. The control group included 5,398 children without an ADHD diagnosis who never scored high on the hyperactivity/inattention subscale.
All children were weighed during each wave of data collection, and parents reported birth weights at the first wave.
Though children in the ADHD group weighed less on average at birth compared with the control group, the difference in weight between the two groups was not significant at 9 months or 3 years. However, those in the ADHD group were significantly more likely to have obesity from age 5 onwards, after excluding children taking stimulants. Further, higher ADHD symptoms as measured on the SDQ scale at ages 7, 11, and 14 were significantly associated with higher body mass index (BMI) scores at the next data wave among girls. This association was only seen in boys at ages 11 and 14.
The findings suggest that there may be a sensitive period between the ages of 3 and 5 during which higher ADHD symptoms become associated with obesity, the authors wrote. Additionally, the later association between higher ADHD symptoms and higher BMI scores may relate to increasing independence regarding food choices as children age, the authors posited. “Those with higher levels of impulsivity may be less likely to make healthier choices,” they wrote.
(Image: Getty Images/iStock/XiXinXing)
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