*2.2. Samples*

Participants in the first sub-study were 10 children 9–11 years old, 10 adolescents 14–16 years old and 10 adults 23–44 years old. They were recruited among staff and students and their children by written and verbal information at the Department of Food and Nutrition, and Sport Science in Sweden and among their friends and children [17]. All participants provided informed consent and the protocol was approved by the ethical committee at the University of Gothenburg.

The second sub-study used Swedish data collected in the European I.Family study (EC: FP7, No. 266044) [20], which is an extension of the IDEFICS study (EC: FP6, No. 016181) investigating children's health, as well as data collected in the LIV2013 study of adult's health in Sweden [21]. The I.Family sample consisted of 417 Swedish children and adolescents (50% female) with a mean (SD) age of 10.9 (2.4) years, the range being 4–16 years. The LIV2013 study consisted of 735 Swedish adults (24% female) with a mean (SD) age of 48.4 years (11.6), the range being 21–67 years. The participants in these studies have provided informed consents and the studies have been approved by the ethical committees.
