Obesity in children is an important health problem in Europe. It has been linked to adverse psychological, social and health consequences in childhood and later in life. Prevention is an important way to combat the childhood obesity epidemic. Even though literature seems clear on some factors that are related to childhood obesity, results regarding other factors including dietary factors are still inconsistent. (1,2) The WHO European Childhood Obesity Surveillance Initiative (COSI) was established in 2008 to measure systematically childhood obesity in the European region. Ireland is one of the countries that contribute to COSI. (3) In the Irish study, data of 1885 (894 boys, 991 girls) Irish primary school children attending first class in 2010 or 2012, who underwent anthropometric assessment and whose parents filled out a family survey were included (response rate: 62·1% of all children whose parents gave consent to fill out a questionnaire). The aim was to determine contributing factors, including several dietary factors, of childhood obesity.Body mass index (BMI) and waist circumference (WC) were standardised by age and sex. For BMI, overweight (including obesity) was classified using the International Obesity Taskforce cut-off points. For WC, British 1990 data was used to compute z-scores and overweight was defined as a z-score≥1·33 (91 st centile). Parents filled out a questionnaire on several factors including the child's dietary intake frequency of several food items, physical activity/inactivity pattern of the child, and family's socioeconomic characteristics. Backward stepwise elimination in the logistic regression was used to identify factors related to childhood obesity, using BMI in one model and WC in a second model as the outcome variable. These variables were dichotomised as normal versus overweight and obese combined. The STATA survey commands were used to adjust for sampling design.Overweight and obesity combined using BMI as the outcome, were more likely in girls (OR 1·47, 95%CI 1·07-2·03), children who were heavier at birth (kg: OR 1·56, 95% CI 1·09-2·24), not breastfed (OR 1·66, 95%CI 1·14-2·42), not living in detached houses/ bungalows (semi-detached house/ bungalow: OR 1·74, 95%CI 1·30-2·32; apartment/shared/other: OR 3·53, 95%CI 1·67-7·45). When using WC as the outcome, results were similar with overweight and obesity combined being more likely in girls, children who were heavier at birth and not living in detached houses/bungalows. Child's frequency of intake of dietary factors such as fruits, vegetables, soft drink (both sugary and diet), sweet snacks, salted snacks and fast food items as reported by the parent, were not associated with the outcomes. These findings might, however, be explained by other factors such as the possibility of self-report bias.In the current study, early life factors and socio-economic status were associated with overweight and obesity, whereas dietary factors were not predictive in 6-7-year-old Irish children.

Obesity in children is an important health problem in Europe (1) . It has been linked to adverse psychological, social and health consequences in childhood and later in life (2) . The World Health Organisation (WHO) Childhood Obesity Surveillance Initiative was established in 2008 to measure systematically childhood obesity in the European region. The present study provides an assessment of the prevalence of obesity from three sweeps of 7 year old Irish children measured in 2008, 2010 and 2012. The core objective was to measure weight, height and waist circumference in primary school children according to the WHO protocol (3) . A nationally representative sample of schools was chosen on a probability proportional to size basis. In large schools, the average class size was estimated to be 20, small schools having less than 20 pupils per class.Body mass index was standardised by age and sex and overweight and obesity were classified using the International Obesity Taskforce (IOTF) cut-off points (4) . Pearson's chi-squared tests were used to determine differences and to assess a linear trend in the prevalence of overweight across different sweeps.In total, 4,349 children had their measurements recorded (2,153 boys and 2,196 girls). Overall response rate for first class in schools was 73.8% for 2008, 64.6 % for 2010 and 54.6 % in 2012. When categorised by IOTF standards, the percentages of overweight children were 22.7%, 20.7 % and 17.8% for sweeps 2008, 2010 and 2012, respectively. For obesity, these percentages were 6.2%, 4.2% and 3.8%, respectively. There was a significant difference between different sweeps for prevalence of overweight (c 2 = 10.1, p = 0.006) and of obesity (c 2 = 10.7, p = 0.005) for all children. Also, a significant inverse linear trend was observed for both overweight (p for trend = 0.002) and obesity (p for trend = 0.002). When analyses were done separately for boys and girls, no significant differences were observed for overweight and obesity among boys, although a significant inverse trend was observed for obesity (p for trend = 0.02). For girls, a significant difference and a significant inverse trend was observed for both overweight and obesity (c 2 = 6.1, p = 0.046, p for trend = 0.02) and for obesity (c 2 = 6.1, p = 0.049, p for trend = 0.05). We investigated whether the drop in prevalence rates could have been attributed to the drop in response rates for first class over the years. However, there was no significant difference in prevalence of overweight and obese children among high response rate schools (P60 % children in first class examined in a school) and low response rate schools ( < 60 %) within each sweep. Also, there was no significant difference in prevalence among schools that did participate in 2008, but did not participate in the other sweeps.In conclusion, it seems that the prevalence of overweight and obesity in Irish children aged 7 years has stabilized and maybe even dropped over the years.