OBJECTIVE: There have been numerous reports on association between attention-deficit/hyperactivity disorder (ADHD) and overweight/obesity in children and adolescents; however, most studies adjusted only for a limited number of possible confounders. METHODS: We analyzed the data of 11 159 six through seventeen-year-old participants in the German Health Interview and Examination Survey for Children and Adolescents. We determined weight status based on measured anthropometry and national reference data by International Obesity Task Force criteria. The parent-rated hyperactivity/inattention subscale of the Strengths and Difficulties Questionnaire (SDQ-HI) was used as a continuous measure of ADHD symptoms. We examined whether the putative confounders socioeconomic status, migrant status, parental body mass index (BMI) and parental smoking were associated with both SDQ-HI and overweight/obesity. Associations between SDQ-HI and overweight/obesity vs normal weight were analyzed by binary logistic regression analyses. In the first model, we adjusted for age and sex only and in the second model also for the parental confounders. RESULTS: SDQ-HI was associated with an increased risk for overweight/obesity in both sexes adjusting for age and sex. However, after adjusting for all confounders SDQ-HI was associated with an increased risk for overweight/obesity only in adolescent females. Socioeconomic status, parental BMI and parental smoking each were relevant confounders. Migrant status was also significantly associated with both SDQ-HI and overweight/obesity, thus qualifying as a confounder but contributed only weakly to the association. CONCLUSIONS: The association between ADHD symptoms and overweight/obesity is due to confounding by family background variables in all but adolescent girls. Possible reasons for the increased risk for overweight/obesity in this subgroup are discussed. We also propose possible mechanisms for confounding by parental socioeconomic status, BMI and smoking.

IntroductionThe aim of the study was to assess the association between attention deficit/hyperactivity disorder (ADHD) symptoms and potentially obesogenic behaviors.MethodsData of 11,676 German children and adolescents (6–17 years) were analyzed. Television/video exposure, physical activity, food frequency and portion size were assessed using questionnaires. A dietary quality index, energy density and volumes of consumed food, and total energy intake were calculated. The parent-rated hyperactivity/inattention subscale of the Strengths and Difficulties Questionnaire (SDQ-HI) was used as a continuous measure of ADHD symptoms. Associations were analyzed with general linear models adjusting for sex, age, socioeconomic status, migrant status, parental BMI, and parental smoking.ResultsSDQ-HI scores correlated positively with physical activity, average energy density of food, volume of beverages, total energy intake, and television exposure and negatively with the nutritional quality score (HuSKY) even after adjustment for parental variables (BMI, smoking, socioeconomic status, migrant status), age, sex, as well as the other SDQ subscales. The adjusted association of the SDQ-HI scores with the nutritional quality score was stronger in girls and the associations with food volume, food energy, and total energy intake was significant only in girls.ConclusionsPoor nutritional quality, high energy intake and television exposure appear to be independently associated with ADHD symptoms. The relationship between food energy intake and ADHD symptoms was especially pronounced in girls and this may help to explain the reported association of ADHD symptoms with overweight in adolescent girls.