This Key Finding reports on data from the second wave of interviews with Growing Up in Ireland’s Child Cohort. The 8,568 children and their families were first interviewed when the children were 9 years old, and then at age 13 years, when 7,400 were reinterviewed between August 2011 and February 2012.

The findings show that boys and young people from more socially advantaged backgrounds were more likely to exercise, and that 13-year-olds who took more exercise (whether hard or light exercise) were less likely to be overweight or obese.

While most of the young people in Growing Up in Ireland maintained a healthy weight over time, one in four was either overweight or obese, a finding similar to that at 9 years. Girls were also more likely to be classified as overweight or obese than boys. The majority of 13-year-olds were quite positive about their physical appearance, although a quarter rated themselves as below average in this respect, and girls tended to be less positive about their body image than boys. Dieting behaviours had also become evident at 13.

To understand more fully the origins and course of overweight and obesity, the descriptive data in this Key Finding can be used in more complex analyses drawing on the rich data available on the child, family and other important contextual variables.