Dr George Thomas
Postdoctoral Research Fellow
School of Human Movement and Nutrition Sciences
Associate Member of Centre for Community Health and Wellbeing
Centre for Community Health and Wellbeing
Researcher biography
Dr George Thomas is a Research Fellow in the School of Human Movement and Nutrition Sciences at The University of Queensland and a member of the ARC Centre of Excellence for the Digital Child. His research focuses on children’s digital technology use, family digital routines, healthy screen use, and child health and wellbeing.
George leads an integrated program of research focused on understanding and improving how families manage children’s screen use. His work spans digital health, behavioural science, public health, and research translation through partnerships with government and industry.
His research has informed international policy and guidelines, including reports from UNESCO and the World Health Organization, and contributes to global initiatives such as the Active Healthy Kids Global Alliance.
George is also committed to education and mentorship, having supervised more than 40 student research projects across psychology, dietetics, and exercise science, and supporting students to work on real-world policy and community initiatives.
Publications
Book Chapter
Biddle, Stuart J.H., Andriyani, Fitria Dwi and Thomas, George (2026). Screens, health and sedentary lifestyles: the need to recognise complexity, function and context. Routledge handbook of digital technologies in sport, exercise and physical education. (pp. 36-51) edited by Victoria A. Goodyear and Andrea Bundon. Abingdon, Oxon, United Kingdom: Routledge. doi: 10.4324/9781003411758-4
Journal Articles
Thomas, George, Lau, Samara, Gomersall, Sjaan, Stylianou, Michalis, Bourke, Matthew, Duncombe, Stephanie L., Vergeer, Ineke, Morawska, Alina, Trost, Stewart, Cairney, John and Biddle, Stuart (2026). Parental knowledge, attitudes, and perceived usefulness of Australian screen time guidelines for toddlers and preschoolers. Health Promotion Journal of Australia, 37 (2) e70178, 1-11. doi: 10.1002/hpja.70178
Bourke, Matthew, Walker, Jacqueline L., Thomas, George, Fortnum, Kathryn and O'Flaherty, Martin (2026). Association between healthy lifestyle behaviors and mental health symptoms in children with autism and ADHD: a latent profile analysis. Autism Research e70238, e70238. doi: 10.1002/aur.70238
Bourke, Matthew, Maddren, Claudia I., Sippel, Franziska and Thomas, George (2026). Within-Person Association Between Daily Screen Use and Sleep in Youth. Jama Pediatrics. doi: 10.1001/jamapediatrics.2025.6490
Thomas, George and Campbell, Marilyn (2026). Healthy technology use in schools: implications for screen time, social media, and smartphone use. Journal of Psychologists and Counsellors in Schools, 36 (1), 3-6. doi: 10.1177/20556365261426201
Thomas, George, Bourke, Matthew, Duncombe, Stephanie L., Pattinson, Cassandra L., Vergeer, Ineke, Biddle, Stuart J.H., Gomersall, Sjaan and Stylianou, Michalis (2026). The digital home in early childhood: classifications of digital landscapes among young Australian children. Journal of Psychologists and Counsellors in Schools, 36 (1) 20556365261422013, 38-51. doi: 10.1177/20556365261422013
Bourke, Matthew, O'Flaherty, Martin, Fortnum, Kathryn, Thomas, George and Walker, Jacqueline L. (2026). Examining health behaviour profiles among children with autism and ADHD using latent profile analysis. Research in Autism, 130 202751, 202751. doi: 10.1016/j.reia.2025.202751
Farletti, Rebecca, Walker, Jacqueline L., Chai, Li Kheng, Campbell, Miranda, Munro, Joanna, Thomas, George, Cairney, John and Littlewood, Robyn (2026). Send in the squad—Podsquad! Using design thinking as a framework to develop a public health promotion programme. Health Promotion Journal of Australia, 37 (1) e70136, 1-11. doi: 10.1002/hpja.70136
Tweedy, Sean, Fortnum, Kathryn, Thomas, George, Cole, Damien, Demetriou, Bridget, Dutia, Iain, Hill, Jessica, Cairney, John and Beckman, Emma (2025). An analysis of people with disabilities in Australia by age, sex, disability type and severity – Implications for leveraging the 2032 Paralympic games to increase physical activity participation. JSAMS Plus, 6 100110, 1-9. doi: 10.1016/j.jsampl.2025.100110
Fortnum, Kathryn, Thomas, George, Too, Kiara, Tam, Athena, Tilley, Kate, Cairney, John, Healy, Genevieve N. and Gomersall, Sjaan (2025). The role of lifestyle factors in type 2 diabetes in children and adolescents: a systematic review. BMC Public Health, 25 (1) 3675, 1-11. doi: 10.1186/s12889-025-23767-0
Sim, Stephanie, Zabatiero, Juliana, Bear, Natasha, Beynon, Amber, Thomas, George, Srinivasjois, Ravisha, Jongeling, Brad, Silva, Desiree and Straker, Leon (2025). Longitudinal associations between maternal and child screen use at 1 year of age and child behavior and development at 3 years of age. BMC Pediatrics, 25 (1) 791, 1-14. doi: 10.1186/s12887-025-05701-w
Wang, Hiu Fei Wendy, Smith, Simon S., O’Flaherty, Martin, Trost, Stewart G., Thomas, George, Walker, Jacqueline L., Fortnum, Kathryn, McNaughton, Sarah, Cairney, John and Bourke, Matthew (2025). Associations between screen time, sleep quality, diet quality and food selectivity among school-aged autistic children. Journal of Autism and Developmental Disorders, 1-14. doi: 10.1007/s10803-025-07064-8
Bourke, Matthew, Wang, Hiu Fei Wendy, Fortnum, Kathryn, Thomas, George, O'Flaherty, Martin, Mulcahy, Samantha K., Gomersall, Sjaan R., Alsop, Tahlia, Trost, Stewart G., Bruijns, Brianne A., Phillips, Sophie M., Vanderloo, Leigh, Tucker, Patricia, Hesketh, Kylie D., Kwan, Matthew Y. W. and Cairney, John (2025). Association between 24-h movement behaviors and mental health in children and adolescents: a systematic review and compositional data meta-analysis. Scandinavian Journal of Medicine and Science in Sports, 35 (8) e70120, 1-18. doi: 10.1111/sms.70120
Andriyani, Fitria Dwi, Hastuti, Tri Ani, Ries, Francis, Sari, Indah Prasetyawati Tri Purnama, Andrianto, Sigit Dwi, Thomas, George and Biddle, Stuart J. H. (2025). Correlates of physical activity among 4,719 Indonesian adolescents: the role of sociodemographic, screen time, and sports participation. International Journal of Human Movement and Sports Sciences, 13 (4), 942-953. doi: 10.13189/saj.2025.130430
Healy, Genevieve N., Melendez-Calderon, Alejandro, Kaab, Sami, Bongers, Noah, Heseltine, Katherine A., Yue, Chan Hi, Thomas, George and Clark, Bronwyn K. (2025). Development, validation, acceptability and usability of a device-based system to measure sit-stand desk usage. Applied Ergonomics, 126 104490, 104490. doi: 10.1016/j.apergo.2025.104490
Bourke, Matthew, Wang, Hiu Fei Wendy, McNaughton, Sarah A., Thomas, George, Firth, Joseph, Trott, Mike and Cairney, John (2025). Clusters of healthy lifestyle behaviours are associated with symptoms of depression, anxiety, and psychological distress: a systematic review and meta-analysis of observational studies. Clinical Psychology Review, 118 102585, 102585. doi: 10.1016/j.cpr.2025.102585
Mavilidi, Myrto F., Vazou, Spyridoula, Lubans, David R., Robinson, Katie, Woods, Andrew J., Benzing, Valentin, Anzeneder, Sofia, Owen, Katherine B., Álvarez-Bueno, Celia, Wade, Levi, Burley, Jade, Thomas, George, Okely, Anthony D. and Pesce, Caterina (2025). How physical activity context relates to cognition across the lifespan: a systematic review and meta-analysis. Psychological Bulletin, 151 (5), 544-579. doi: 10.1037/bul0000478
Bourke, Matthew, Harrison, Zoe, Fortnum, Kathryn, Thomas, George, O'Flaherty, Martin, Mulcahy, Samantha K., Gomersall, Sjaan R., Alsop, Tahlia, Trost, Stewart G., Koplin, Jennifer J., Bruijns, Brianne A., Phillips, Sophie M., Vanderloo, Leigh M., Tucker, Patricia, Hesketh, Kylie D., Kwan, Matthew Y. W. and Cairney, John (2025). Association between 24-hour movement behaviors and adiposity in children and adolescents: A compositional data meta-analysis. Obesity Reviews, 26 (5) e13884, 1-15. doi: 10.1111/obr.13884
O'Flaherty, Martin, Hill, Jessica, Bourke, Matthew, Fortnum, Kathryn, Thomas, George, Gomersall, Sjaan R. and Cairney, John (2025). Unpacking the relationship between autism, sport participation, and adolescent health: a causal mediation analysis. Disability and Health Journal, 18 (3) 101832, 1-8. doi: 10.1016/j.dhjo.2025.101832
Barratt, Jaime, Dudley, Dean, Stylianou, Michalis, Thomas, George, Wheeler, Kai and Cairney, John (2025). Construct validity and reliability of the effective early childhood physical literacy pedagogue (ECE-PLP) self-report instrument. Measurement in Physical Education and Exercise Science, 29 (2), 145-159. doi: 10.1080/1091367x.2024.2422309
Lund Rasmussen, Charlotte, Hendry, Danica, Thomas, George, Beynon, Amber, Stearne, Sarah Michelle, Zabatiero, Juliana, Davey, Paul, Roslyng Larsen, Jon, Rohl, Andrew Lloyd, Straker, Leon and Campbell, Amity (2024). Evaluation of the ActiMotus software to accurately classify postures and movements in children aged 3–14. Sensors, 24 (20) 6705, 6705. doi: 10.3390/s24206705
Fortnum, Kathryn, Gomersall, Sjaan R., Ross, Megan H., Woodforde, James, Thomas, George, Wen, Yu-Shu, Perales, Francisco and Stylianou, Michalis (2024). 24-hour movement behaviors of LGBTQA+ young people: a systematic review. Journal of Physical Activity & Health, 21 (12), 1-17. doi: 10.1123/jpah.2024-0343
Lyons, Althea, Thomas, George, Octigan, Sean and Orme, Joe (2024). Developing best practice guidance for educational psychologists gaining consent across the 0-25 age range. Educational Psychology in Practice, 40 (4), 472-490. doi: 10.1080/02667363.2024.2403072
Bongers, Noah, Healy, Genevieve N., Thomas, George and Clark, Bronwyn K. (2024). Device-based measurement of office-based physical activity and sedentary time: a systematic review. Journal for the Measurement of Physical Behaviour, 7 (1), 10-22. doi: 10.1123/jmpb.2024-0011
Mallawaarachchi, Sumudu, Burley, Jade, Mavilidi, Myrto, Howard, Steven J., Straker, Leon, Kervin, Lisa, Staton, Sally, Hayes, Nicole, Machell, Amanda, Torjinski, Marina, Brady, Brodie, Thomas, George, Horwood, Sharon, White, Sonia L. J., Zabatiero, Juliana, Rivera, Clara and Cliff, Dylan (2024). Early childhood screen use contexts and cognitive and psychosocial outcomes : a systematic review and meta-analysis. JAMA Pediatrics, 178 (10), 1017-1026. doi: 10.1001/jamapediatrics.2024.2620
Khan, Asaduzzaman, Thomas, George, Karatela, Shamshad, Morawska, Alina and Werner-Seidler, Aliza (2024). Intense and problematic social media use and sleep difficulties of adolescents in 40 countries. Journal of Adolescence, 96 (5), 1116-1125. doi: 10.1002/jad.12321
Ayirebi, Katie and Thomas, George (2024). What could be considered as effective support for autistic females in high school? A systematic literature review. The Journal of Research in Special Educational Needs, 24 (3), 441-453. doi: 10.1111/1471-3802.12641
Beynon, Amber, Hendry, Danica, Lund Rasmussen, Charlotte, Rohl, Andrew L., Eynon, Rebecca, Thomas, George, Stearne, Sarah, Campbell, Amity, Harris, Courtenay, Zabatiero, Juliana and Straker, Leon (2024). Measurement method options to investigate digital screen technology use by children and adolescents: a narrative review. Children, 11 (7) 754, 754. doi: 10.3390/children11070754
Sanders, Taren, Noetel, Michael, Parker, Philip, Del Pozo Cruz, Borja, Biddle, Stuart, Ronto, Rimante, Hulteen, Ryan, Parker, Rhiannon, Thomas, George, De Cocker, Katrien, Salmon, Jo, Hesketh, Kylie, Weeks, Nicole, Arnott, Hugh, Devine, Emma, Vasconcellos, Roberta, Pagano, Rebecca, Sherson, Jamie, Conigrave, James and Lonsdale, Chris (2024). An umbrella review of the benefits and risks associated with youths’ interactions with electronic screens. Nature Human Behaviour, 8 (1), 82-99. doi: 10.1038/s41562-023-01712-8
Andriyani, Fitria Dwi, Biddle, Stuart J. H., Priambadha, Aprida Agung, Thomas, George and De Cocker, Katrien (2022). Physical activity and sedentary behaviour of female adolescents in Indonesia: a multi-method study on duration, pattern and context. Journal of Exercise Science & Fitness, 20 (2), 128-139. doi: 10.1016/j.jesf.2022.02.002
Thomas, George, Bennie, Jason A., De Cocker, Katrien, Dwi Andriyani, Fitria, Booker, Bridget and Biddle, Stuart J. H. (2022). Using wearable cameras to categorize the type and context of screen-based behaviors among adolescents: observational study. JMIR Pediatrics and Parenting, 5 (1) e28208, e28208. doi: 10.2196/28208
Thomas, George, Bennie, Jason A., De Cocker, Katrien, Ireland, Michael J. and Biddle, Stuart J. H. (2020). Screen-based behaviors in Australian adolescents: longitudinal trends from a 4-year follow-up study. Preventive Medicine, 141 106258, 106258. doi: 10.1016/j.ypmed.2020.106258
Thomas, George, Bennie, Jason A., De Cocker, Katrien and Biddle, Stuart J.H. (2020). Exploring contemporary screen time in Australian adolescents: a qualitative study. Health Promotion Journal of Australia, 32 (S2), 238-247. doi: 10.1002/hpja.440
Thomas, George, Bennie, Jason A., De Cocker, Katrien, Castro, Oscar and Biddle, Stuart J. H. (2020). A descriptive epidemiology of screen-based devices by children and adolescents: a scoping review of 130 surveillance studies since 2000. Child Indicators Research, 13 (3), 935-950. doi: 10.1007/s12187-019-09663-1
Biddle, Stuart J. H., Ciaccioni, Simone, Thomas, George and Vergeer, Ineke (2019). Physical activity and mental health in children and adolescents: an updated review of reviews and an analysis of causality. Psychology of Sport and Exercise, 42, 146-155. doi: 10.1016/j.psychsport.2018.08.011
Bennie, J. A., Thomas, G., Wiesner, G. H., van Uffelen, J. G.Z., Khan, A., Kolbe-Alexander, T., Vergeer, I. and Biddle, S. J.H. (2018). Australian fitness professionals’ level of interest in engaging with high health-risk population subgroups: findings from a national survey. Public Health, 160, 108-115. doi: 10.1016/j.puhe.2018.03.035
Conference Papers
Stylianou, Michalis, Woodforde, James, Duncombe, Stephanie, Thomas, George, Lee, Jessica, Hill, Jessica and Gomersall, Sjaan (2025). Physical activity environments and behaviours in Outside School Hours Care. Asia-Pacific Society for Physical Activity, Newcastle, NSW Australia, 25-27 November 2025.
Thomas, George, Gilson, Nick, Alley, Stephanie, Browne, Meighan, Duncan, Mitch and Vandelanotte, Corneel (2025). AI-assisted screening in large-scale reviews: a case example from a bibliometric study on physical activity technologies. Asia-Pacific Society for Physical Activity, Newcastle, NSW, Australia, 25-27 November 2025.
Gilson, Nick, Thomas, George, Alley, Stephanie, Browne, Meighan, Duncan, Mitch and Vandelanotte, Corneel (2025). Technology for physical activity promotion: A bibliometric analysis over four decades using an AI-human hybrid search and selection model. Asia-Pacific Society for Physical Activity, Newcastle, NSW, Australia, 25-27 November 2025.
Thomas, George, Mulchay, Samantha, Gomersall, Sjaan, Richards, Justin and Andrews, Lara (2025). Bridging the gap between research and practice through government and academic partnerships: opportunities, challenges and lessons learned from Australia and New Zealand. International Society of Behavioural Nutrition and Physical Activity, Auckland, New Zealand, 11-14 June 2025.
Thomas, George, Duncombe, Stephanie, Gomersall, Sjaan, Morawska, Alina, Vergeer, Ineke and Biddle, Stuart (2025). Do barriers, enablers, and support needs for screen use management differ by presence of siblings among Australian parents of young children?. International Society of Behavioural Nutrition and Physical Activity, Auckland, New Zealand, 11-14 June 2025.
Mallawaarachichi, Sumudu, Burley, Jade, Mavilidi, Myrto, Howard, Steven, Straker, Leon, Kervin, Lisa, Staton, Sally, Hayes, Nicola, Machell, Amanda, Torjinski, Marina, Brady, Brodie, Thomas, George, Horwood, Sharon, White, Sonia, Zabatiero, Julianna, Rivera, Clara and Cliff, Dylan (2024). Associations of early childhood screen use contexts with cognitive and psychosocial outcomes: A systematic review and meta-analysis. International Society for Physical Activity and Health, Paris, France, 28-31 October 2024.
Rasmussen, Charlotte, Hendry, Danica, Thomas, George, Beynon, Amber, Stearne, Sarah, Zabatiero, Julianna, Davey, Paul, Rohl, Andrew, Straker, Leon and Campbell, Amity (2024). Evaluation of the Motus wearable-sensor-based system to classify postures and movements in 3-14 aged children. International Society for Physical Activity and Health, Paris, France, 28-31 October 2024.
Beynon, Amber, Hendry, Danica, Rasmussen, Charlotte, Rohl, Andrew, Eynon, Rebecca, Thomas, George, Stearne, Sarah, Campbell, Amita, Harris, Courtney, Zabatiero, Julianna and Straker, Leon (2024). Better methods to provide stronger evidence on health implications of screen use by children. International Society for Physical Activity and Health, Paris, France, 28-31 October 2024.
Khan, Asad, Thomas, George and Cairney, John (2024). Does sports participation attenuate the relationship between screen time and quality of life of children?. International Society for Physical Activity and Health, Paris, France, 28-31 October 2024.
Bourke, Matthew, Thomas, George, Fortnum, Kathryn, O'Flaherty, Martin and Gomersall, Sjaan (2024). Meta-analysis of association between 24-hour movement behaviours and social-emotional and cognitive outcomes in youth. International Society for Physical Activity and Health, Paris, France, 28-31 October 2024.
Thomas, George, Vergeer, Ineke, Rowland, Deborah, Kolbe-Alexander, Tracy, Krishnamoorthy, Govind, March, Sonja, Gomersall, Sjaan and Biddle, Stuart (2024). Exploring Australian parents’ perceptions of young children’s screen use. International Society for Physical Activity and Health, Paris, France, 28-31 October 2024.
Pattinson, C. L., Thomas, G., Mann, D. L., MacKenzie, J., Rossa, K. R., Edmed, S. L., Westwood, E. and Smith, S. S. (2024). Everyday environmental light exposures in children. 10th International Society for Physical Activity and Health Congress, Paris, France, 28-31 October 2024.
Thomas, George, Clark, Bronwyn and Healy, Genevieve (2024). Accuracy and Acceptability of the Desk Positioning System (DPS): a new sit-stand desk measurement device. International Society for the Measurement of Physical Behaviour, Rennes, France, 17-21 June 2024.
Clark, Bronwyn, Thomas, George, Bongers, Noah and Healy, Genevieve (2024). Device-based measurement of office-based physical behaviour: a systematic review. International Society for the Measurement of Physical Behaviour, Rennes, France, 17-21 June 2024.
Khan, Asad and Thomas, George (2023). Associations between excessive and problematic social media use and psychosomatic complaints among adolescents: does physical activity moderate the associations?. Asia-Pacific Society for Physical Activity, Wellington, New Zealand, 27 - 29 November 2023.
Fortnum, Kathern, Thomas, George, Too, Kiara, Tam, Athena, Tilley, Kate, Cairney, John and Gomersall, Sjaan (2023). Lifestyle management of youth impacted by type 2 diabetes: A systematic review. Asia-Pacific Society for Physical Activity, Wellington, New Zealand, 27-29 November 2023.
Thomas, George, Bennie, Jason, De Cocker, Katrien and Biddle, Stuart (2023). Exploring contemporary screen time in Australian adolescents: A qualitative study. Asia-Pacific Society for Physical Activity, Wellington, New Zealand, 27-29 November.
Thomas, George, Bennie, Jason, De Cocker, Katrien, Andriyani, Fitria Dwi and Biddle, Stuart (2023). Using automated wearable cameras to categorise the type and context of screen-based behaviours among adolescents: an observational study. Asia-Pacific Society for Physical Activity, Wellington, New Zealand, 27-29 November 2023.
Richard, Veronique, Thomas, George, Gomersall, Sjaan and Cairney, John (2023). On the centrality of (movement) creativity to enrich the sustainability of physical literacy. International Physical Literacy Conference, New York, United States, 1-3 May 2023.
Thomas, G., Bennie, J., De Cocker, K., Sanders, T. and Biddle, S. J. H. (2020). Screen-based behaviors in Australian adolescents: longitudinal trends from 2010 to 2014. International Society for Behavioral Nutrition and Physical Activity, Online, 15-25 June 2020.
Biddle, S. J. H., Ciaccioni, S., Thomas, G. and Vergeer, I. (2019). Physical activity and self-esteem outcomes in young people: what can we conclude from research syntheses?. Australasian Society for Behavioural Health and Medicine , Christchurch, New Zealand, 15-17 February 2019.
Lonsdale, Chris, Biddle, Stuart, Parker, Phil, Salmon, Jo, Hesketh, Kylie, Thomas, George, Weeks, Nicole and Sanders, Taren (2018). Benefits and risks associated with children and adolescents' interactions with electronic screens: A synthesis of 474 systematic reviews. CHAMPAIGN: HUMAN KINETICS PUBL INC.
Thomas, G., Bennie, J., De Cocker, K. and Biddle, S. J. H. (2018). Screen time use among children and adolescents: methodology for a scoping review and preliminary findings. Exercise and Sports Science Australia: Research to Practice , Brisbane, Australia, 27-29 March 2018.
Thomas, G., Bennie, J., De Cocker, K. and Biddle, S. J. H. (2018). Time-use in screen-based devices among children and adolescents: a systematic scoping review of large population-based studies published since 2000. International Society for Physical Activity and Health, London, United Kingdom, 15-17 October 2018. CHAMPAIGN: HUMAN KINETICS PUBL INC.
Ciaccioni, S., Thomas, G., Vergeer, I. and Biddle, S. J. H. (2018). Physical activity and self-esteem in children and adolescents: update of review of reviews. European College of Sport Science , Dublin, Ireland, 4-7 July 2018.
Preprint
Fortnum, Kathryn, Bourke, Matthew, Thomas, George, Mulcahy, Samantha, Alsop, Tahlia and Gomersall, Sjaan (2025). Promoting mental wellbeing and recovery across the lifespan: a review of evidence. doi: 10.31219/osf.io/y7uwj_v1
Research Report
Zabatiero, Juliana, Thomas, George and Straker, Leon (2022). Screen time. In Active Healthy Kids Australia (2022). Reboot! Reimagining Physically Active Lives: 2022 Australian Report Card on Physical Activity for Children and Young People. Melbourne, Australia: Active Health Kids Australia.