[1] Wu, XY, Han, LH, Zhang, JH, et al. The influence of physical activity, sedentary behavior on health-related quality of life among the general population of children and adolescents: A systematic review. PLoS One 2017;12:e0187668.
Google Scholar | Crossref | Medline[2] Wang, Y, Lim, H. The global childhood obesity epidemic and the association between socio-economic status and childhood obesity. Int Rev Psychiatry 2012;24:176–88.
Google Scholar | Crossref[3] World Health Organization . Obesity and overweight, https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight (2021, accessed 10 March 2021).
Google Scholar[4] World Health Organization . Adolescent health, https://www.who.int/health-topics/adolescent-health#tab=tab_1 (2021, accessed 10 March 2021).
Google Scholar[5] World Health Assembly . (2016). Report of the Commission on Ending Childhood Obesity: report by the Director-General. World Health Organization, https://apps.who.int/gb/ebwha/pdf_files/WHA69/A69_8-en.pdf (2016, accessed 28 April 2020).
Google Scholar[6] Moore, SC, Patel, AV, Matthews, CE, et al. Leisure time physical activity of moderate to vigorous intensity and mortality: a large pooled cohort analysis. PLoS Med 2012;9:e1001335.
Google Scholar | Crossref | Medline[7] World Health Organization . Physical activity, https://www.who.int/news-room/fact-sheets/detail/physical-activity (2020, accessed 10 March 2021).
Google Scholar[8] Bakken, A . Idrettens posisjon i ungdomstida. Hvem deltar og hvem slutter i ungdomsidretten? [The position of sport in youth. Who participates and who quits in youth sports?]. Report no. 9788278946909, 8278946906, 2019. NOVA, OsloMet.
Google Scholar[9] Steene-Johannessen, J, Alfred Anderssen, S, Bratteteig, M, et al. Kartlegging av fysisk aktivitet, sedat tid og fysisk form blant barn og unge 2018 (ungKan3) [Physical Activity among Norwegian Children Study]. 2019. Norges Idrettshøyskole: Norges Idrettshøyskole, Folkehelseinstituttet.
Google Scholar[10] Guthold, R, Stevens, GA, Riley, LM, et al. Global trends in insufficient physical activity among adolescents: a pooled analysis of 298 population-based surveys with 1·6 million participants. Lancet Child Adolesc Health 2020;4:23–35.
Google Scholar | Crossref | Medline[11] World Health Organization . Adolescent obesity and related behaviours: trends and inequalities in the WHO European Region, 2002–2014 . WHO, 2017.
Google Scholar[12] Stalsberg, R, Pedersen, AV. Effects of socioeconomic status on the physical activity in adolescents: a systematic review of the evidence. Scand J Med Sci Sports 2010;20:368–83.
Google Scholar | Crossref | Medline[13] Heradstveit, O, Haugland, S, Hysing, M, et al. Physical inactivity, non-participation in sports and socioeconomic status: a large population-based study among Norwegian adolescents. BMC Public Health 2020;20:1010.
Google Scholar | Crossref | Medline[14] Norwegian Directorate of Health and Social Affairs . Gradientutfordringen. Sosial- og helsedirektoratets handlingsplan mot sosiale ulikheter i helse [The challenge of the gradient. The Directorate of Health and Social Affairs action plan against social inequalities in health]. Report no. 8280810609, 2005. Oslo.
Google Scholar[15] Dahl, E, Bergli, H, Wel, KAvd. Sosial ulikhet i helse : en norsk kunnskapsoversikt [Review of Social Inequalites in Health in Norway]. 2014. Oslo: Høgskolen i Oslo og Akershus.
Google Scholar[16] Norwegian Institute of Public Health . Folkehelserapporten - Helsetilstanden i Norge [The Public Health Report - Health Status in Norway 2018], https://fhi.no/nettpub/hin/ (2018, accessed 5 October 2020).
Google Scholar[17] Public Health Act . Lov om folkehelsearbeid (Folkehelseloven) [Law on public health (Public Health Act)]. 2012.
Google Scholar[18] Mackenbach, JP, Kunst, AE, Cavelaars, AEJM, et al. Socioeconomic inequalities in morbidity and mortality in western Europe. Lancet 1997;349:1655–59.
Google Scholar | Crossref[19] Mackenbach, JP, Stirbu, I, Roskam, AJ, et al. Socioeconomic inequalities in health in 22 European countries. N Engl J Med 2008;358:2468–81.
Google Scholar | Crossref | Medline[20] Berntsen, KN. Forventet levealder i Oslos bydeler. Fortsatt store forskjeller i levealder i Oslo. Samfunnsspeilet, 2013; 4/2013.
Google Scholar[21] Ljunggren, J. Oslo og sosial ulikhet. In: Ljunggren, J (ed) Oslo : ulikhetenes by. Oslo: Cappelen Damm akademisk, 2017, pp.13–30.
Google Scholar[22] Andersen, PL, Bakken, A. Social class differences in youths’ participation in organized sports: What are the mechanisms? Int Rev Soc Sport 2019;54:921–37.
Google Scholar[23] Bakken, A, Osnes, SM. Ung i Oslo 2021 - 5. til 7. trinn [Young in Oslo 2021 - 5th to 7th grade]. 2021. Oslo: NOVA, OsloMet.
Google Scholar[24] Mehtälä, A, Villberg, J, Blomqvist, M, et al. Individual- and environmental-related correlates of moderate-to-vigorous physical activity in 11-, 13-, and 15-year-old Finnish children. PLoS One 2020;15:e0234686.
Google Scholar | Crossref | Medline[25] de Vet, E, de Ridder, DT, de Wit, JB. Environmental correlates of physical activity and dietary behaviours among young people: a systematic review of reviews. Obes Rev 2011;12:e130–42.
Google Scholar | Crossref | Medline[26] Sallis, JF, Cervero, RB, Ascher, W, et al. An ecological approach to creating active living communities. Annu Rev Public Health 2006;27:297–322.
Google Scholar | Crossref | Medline | ISI[27] Sallis, JF, Owen, N, Fisher, EB. Ecological models of health behavior. In: Glanz, K, Rimer, BK, Viswanath, K (eds) Health behavior and health education: theory, research, and practice. 4th ed. ed. San Francisco, Calif: Jossey-Bass, 2008, pp.465–85.
Google Scholar[28] McLeroy, KR, Bibeau, D, Steckler, A, et al. An ecological perspective on health promotion programs. Health Educ Q 1988;15:351–77.
Google Scholar | SAGE Journals[29] Brattbakk, I, Andersen, B. Oppvekststedets betydning for barn og unge : nabolaget som ressurs og utfordring [The importance of the neighbourhood for children and adolescents growing up: the neighbourhood as a resource and a challenge] Oslo: Arbeidsforskningsinstituttet, 2017.
Google Scholar[30] Berkman, LF, Kawachi, I. A historical framework for social epidemiology: social determinants of population health. In: Berkman, LF, Kawachi, I, Glymour, MM (eds) Social epidemiology. 2nd ed. New York: Oxford University Press, 2014, pp.1–16.
Google Scholar[31] Draper, CE, Grobler, L, Micklesfield, LK, et al. Impact of social norms and social support on diet, physical activity and sedentary behaviour of adolescents: a scoping review. Child Care Health Dev 2015;41:654–67.
Google Scholar | Crossref | Medline[32] Jonsson, L, Larsson, C, Berg, C, et al. What undermines healthy habits with regard to physical activity and food? Voices of adolescents in a disadvantaged community. Int J Qual Stud Health Well-being 2017;12:1333901.
Google Scholar | Crossref | Medline[33] Smith, M, Hosking, J, Woodward, A, et al. Systematic literature review of built environment effects on physical activity and active transport - an update and new findings on health equity. Int J Behav Nutr Phys Act 2017;14:158.
Google Scholar | Crossref | Medline[34] Martins, J, Costa, J, Sarmento, H, et al. Adolescents’ perspectives on the barriers and facilitators of physical activity: an updated systematic review of qualitative studies. Int J Environ Res Public Health 2021;18:4954.
Google Scholar | Crossref | Medline[35] Anselma, M, Chinapaw, MJM, Altenburg, TM. Determinants of child health behaviors in a disadvantaged area from a community perspective: a participatory needs assessment. Int J Environ Res Public Health 2018;15:644.
Google Scholar | Crossref[36] Jonsson, L, Berg, C, Larsson, C, et al. Facilitators of physical activity: voices of adolescents in a disadvantaged community. Int J Environ Res Public Health 2017;14:839.
Google Scholar | Crossref[37] Health Research Act . Lov om medisinsk og helsefaglig forskning (helseforskningsloven), [Act on Medical and health Research (Health Research Act)]. 2008.
Google Scholar[38] Malterud, K . Etiske utfordringer ved kvalitative studier In: Malterud, K (ed) Kvalitative metoder i medisinsk forskning : en innføring [Ethical challenges in qualitative studies In Malterud, K (Ed), Qualitative Methods in Medical Research : An Introduction] 2. utg. ed. Oslo: Universitetsforl., 2003, pp.93–207.
Google Scholar[39] Oslo Municipality . Oslo kommune statistikkbanken [Oslo municipality statistics bank], http://statistikkbanken.oslo.kommune.no/webview/ (2021, accessed 2 September 2021).
Google Scholar[40] Oslo Municipality . Skoler i Oslo [Schools in Oslo], https://www.oslo.kommune.no/skole-og-utdanning/skoleoversikt-og-skoletilhorighet/skoler-i-oslo/ (2019, accessed 26 February 2019).
Google Scholar[41] Skreden, M . Ungdom og kosthold, . In: Engeset, D, Torheim, LE, Øverby, NC (eds) Samfunnsernæring. Oslo: Universitetsforl., 2019, pp.74–77.
Google Scholar[42] Havdal, HH, Fosse, E, Gebremariam, MK, et al. Perceptions of the social and physical environment of adolescents’ dietary behaviour in neighbourhoods of different socioeconomic position. Appetite 2021; 159: 105070. DOI: 10.1016/j.appet.2020.105070.
Google Scholar | Crossref | Medline[43] Malterud, K . Analyse av kvalitative data. Kvalitative metoder i medisinsk forskning : en innføring [Analyses of qualitative data. In Malterud, K (Ed), Qualitative Methods in Medical Research: An Introduction] 2. utg. ed. Oslo: Universitetsforl., 2003, pp.93–113.
Google Scholar[44] Malterud, K . Systematic text condensation: a strategy for qualitative analysis. Scand J Public Health 2012;40:795–805.
Google Scholar | SAGE Journals | ISI[45] Pedersen Gurholt, K . Norwegian friluftsliv and ideals of becoming an ‘educated man’. J Adventure Educ Outdoor Learn 2008;8:55–70.
Google Scholar | Crossref[46] Sharma-Brymer, V, Brymer, E. Norwegian Friluftsliv: a way of living and learning in nature. Annette R. Hofmann, Carsten Gade Rolland, Kolbjørn Rafoss and Herbert Zoglowek, Münster, Germany, 2018, Waxmann Verlag GmbH. J Adventure Educ Outdoor Learning 2019;21:1–3.
Google Scholar[47] Gurholt, KP, Torp, IHD, Eriksen, JW. Studie av friluftsliv blant barn og unge i Oslo: Sosial ulikhet og sosial utjevning [Study of outdoor life among children and young people in Oslo: Social inequality and social equalization]. Report no. 978-82-502-0583-3, 2020. Norges idrettshøgskole.
Google Scholar[48] Bakken, A, Sletten, MA, Eriksen, IM. Generasjon prestasjon? [Generation achievement?]. Tidsskrift for ungdomsforskning 2019; 18.
Google Scholar[49] Uhls, YT, Ellison, NB, Subrahmanyam, K. Benefits and costs of social media in adolescence. Pediatrics 2017;140:S67.
Google Scholar | Crossref | Medline[50] Norwegian Olympic and Paralympic Committee and Confederation of Sports . Statistikk [Statistics], https://www.idrettsforbundet.no/idrettskrets/oslo/om-idrettskretsen/Statistikk/ (2018, accessed 27 August 2020).
Google Scholar[51] Norwegian Ministry of Culture . Kom igjen, jenter! : jenter med minoritetsbakgrunn og deltakelse i organisert idrett : rapport fra et statlig oppnevnt utvalg - avlevert 1. april 2014 til Kulturdepartementet [Come on, girls! : girls with minority backgrounds and participation in organized sports: report from a state-appointed committee - submitted 1 April 2014 to the Ministry of Culture]. Oslo: Kulturdepartementet, 2014.
Google Scholar[52] Strandbu, Å, Bakken, A, Sletten, MA. Exploring the minority–majority gap in sport participation: different patterns for boys and girls? Sport Soc 2019;22:606–24.
Google Scholar | Crossref[53] Stefansen, K, Smette, I, Strandbu, Å. Understanding the increase in parents’ involvement in organized youth sports. Sport Educ Soc 2018;23:162–72.
Google Scholar | Crossref[54] Strandbu, Å, Stefansen, K, Smette, I, et al. Young people’s experiences of parental involvement in youth sport. Sport Educ Soc 2019;24:66–77.
Google Scholar | Crossref[55] Strandbu, Å, Gulløy, E, Andersen, PL, et al. Ungdom, idrett og klasse: Fortid, samtid og framtid [Youth, sports and class: Past, present and future]. Norsk sosiologisk tidsskrift 2017;1:132–51.
Google Scholar | Crossref[56] BUA . BUA er en ideell organisasjon som vil gjøre det enklere å være fysisk aktiv [BUA is a non-profit organization that wants to make it easier to be physically active], https://www.bua.io/artikkel/om-oss (2020, accessed 25 November 2020).
Google Scholar[57] Horner, SD . Using focus group methods with middle school children. Res Nurs Health 2000;23:510–17.
Google Scholar | Crossref | Medline[58] Morgan, DL, Scannell, AU, Krueger, RA. Planning focus groups. Thousand Oaks, Calif: Sage Publications, 1998.
Google Scholar | Crossref