New thesis: Peer, sibling and social media influence on preadolescent children’s healthy eating behaviour

November the 17th, Tija Rageliene (ESR9) defended her thesis “Peer, sibling and social media influence on preadolescent children’s healthy eating behaviour” at Arhus University (School of Business and Social Sciences Department of Management).

Her research objective has been to explore the influence of peers, siblings, and social media on preadolescent children’s healthy eating behaviour. She has focused on the age group 9-13 year olds. Furthermore, to examine if influence can be used in an intervention designed to encourage preadolescents children’s healthy eating behaviour. Through her research she found that peers influence on healthy eating is more often positive than negative, i.e. that peers rather increase the consumption of unhealthy foods rather than increasing the consumption of healthy food. Sibling influences have little importance as the parents govern meal structure and availability of healthy food at home.

As a part of her research, Tija has also developed an app “Food Boss” were children can learn about healthy food and make food diaries with the aim of using this as an intervention. Her results indicate that this app could potentially serve as an attractive and low-cost intervention to reach a wide population of children for the promotion of healthy eating and prevention of childhood obesity.



  • Associate Professor Susanne Pedersen, MGMT, Aarhus University (chair)
  • Associate Professor Ellen van Kleef, Wageningen University, NL
  • Professor David Marshall, University of Edinburgh Business School, UK


  • Associate Professor Alice Grønhøj
  • Professor Jessica Aschemann-Witzel


Basel University Children’s Hospital research department (Switzerland), 2 months


Ragelienė, T. and A. Grønhøj (2020), The influence of peers′ and siblings′ on children’s and adolescents′ healthy eating behavior. A systematic literature review. Appetite, 148: p. 104592.

Ragelienė, T. and A. Grønhøj, (2020) Preadolescents’ healthy eating behavior: peeping through the social norms approach. BMC Public Health, 20(1): p. 1268. doi:10.1186/s12889-020-09366-1

Ragelienė, T. (2021). Do children favor snacks and dislike vegetables? Exploring children’s food preferences using drawing as a projective technique. A cross-cultural study. Appetite, 165, 105276. doi:

Ragelienė, T., & Grønhøj, A. (2021). The role of peers, siblings and social media for children’s healthy eating socialization: a mixed methods study. Food Quality and Preference, 93, 104255.

Ragelienė, T., Aschemann-Witzel, J., & Grønhøj, A. (2021). Efficacy of a smartphone application-based intervention for encouraging children’s healthy eating in Denmark. Health Promotion International. https://doi:10.1093/heapro/daab081


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