Jonathan Bernard PhD in Epidemiology
Course and current status
Researcher at the French National Institute for Health and Medical Research (Inserm)
Centre for Research in Epidemiology and StatisticS (CRESS), Université Paris Cité/Université Sorbonne Paris Nord/Inserm/INRAE, Paris, France.
Desbrest Institute of Epidemiology and Public Health (IDESP), University of Montpellier/Inserm, Montpellier, France.
Main research interests
Epidemiology of the child's development, screen use, physical activity and sedentary behaviour, maternal and child nutrition, breastfeeding, child growth and adiposity, cognitive development.
Education
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2021 |
Habilitation in Epidemiology and Public Health, Université Paris Cité, France |
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2013 |
PhD in Epidemiology and Public Health, Paris-Saclay University, Faculty of Medicine, Kremlin-Bicêtre, France |
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2010 |
Master of Science (MSc) in Health Biology (Master 1), major in Public Health Nutrition (Master 2), University of Montpellier, France |
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2007 |
Bachelor of Science (BSc) in Biology, University of Montpellier, France |
Previous positions
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2017 –2018 |
Research fellow, Inserm, Villejuif, France |
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2014 – 2018 |
Research fellow, Agency for Science, Technology and Reseach (A*STAR), Singapore |
|
2014 |
Postdoctoral researcher, Inserm, Villejuif, France |
Scientific summary
I am an epidemiologist at Inserm specializing in the effects of digital media use on children's and adolescents' health and development.
Since 2018, I have been conducting my research at the Center for Research in Epidemiology and Statistics (CRESS) in Paris. Since 2025, I have also been co-affiliated with the Desbrest Institute of Epidemiology and Public Health (IDESP) in Montpellier.
Originally trained in health biology and nutrition at the University of Montpellier, I then moved into epidemiology and public health. I conducted my PhD (2010-2013, University Paris-Saclay) on the effects of polyunsaturated fatty acids on child neurodevelopment using the EDEN cohort, followed by a postdoctoral fellowship in Singapore (2014-2018), which similarly focused on the effects of fatty acids on child development using the GUSTO cohort. During this postdoctoral fellowship, I progressively broadened my research toward physical activity and screen use, first in the GUSTO cohort, and then, upon returning to France, in the French EDEN and Elfe cohorts.
Today, my work focuses primarily on the determinants of screen use during childhood, and its links with health behaviors (physical activity, diet), physical health (overweight/obesity), cognitive and language development, neurodevelopmental disorders, sleep, and myopia. I currently supervise several engineers, PhD students, and postdoctoral researchers on these topics and coordinate dedicated projects (ANR iSCAN, Anses ExpoNum, AXA MIC@DO).
This expertise has led me to join leading advisory bodies: member of the Anses working group on the health effects of social media on adolescents (2020-2025); member of the "Children and Screens" Commission mandated by the President of the Republic, whose report "Children and Screens: In Search of Lost Time" was submitted to him in 2024; and member of Arcom's young audience expert committee (since 2026). My ability to bridge science, society, and public policy within the "Children and Screens" Commission was recognized with the 2024 Inserm-OPECST Prize.
With more than 120 original publications, I am now recognized as a leading scientific expert on issues related to screens and children's health in France.
Major publications
Vainqueur C, Padmapriya N, Tint MT, Yap F, Lee YS, Saw SM, Tan KH, Shek LP, Chong YS, Godfrey KM, Eriksson JG, Lioret S, Heude B, Muller-Riemenschneider F, Bernard JY, Poncet L. Longitudinal associations between screen time and whole-body adiposity during the first decade of life: insights from the GUSTO cohort. Int J Obes (Lond). 2026;50(5):1097-104. Epub 20260309. doi: 10.1038/s41366-026-02046-x. PubMed PMID: 41803381.
Abou Assi A, Armand M, Sarté C, Tafflet M, Yuan WL, Peyre H, Charles MA, Heude B, Bernard JY. Patterns of perinatal exposure to PUFAs and child neurodevelopment: evidence from Mendelian randomization using FADS cluster variants. Am J Clin Nutr. 2025;122(1):235-43. Epub 2025/07/04. doi: 10.1016/j.ajcnut.2025.03.014. PubMed PMID: 40610128.
Yang S, Said M, Peyre H, Ramus F, Taine M, Law EC, Dufourg MN, Heude B, Charles MA, Bernard JY. Associations of screen use with cognitive development in early childhood: the ELFE birth cohort. J Child Psychol Psychiatry. 2024;65(5):680-93. Epub 20230829. doi: 10.1111/jcpp.13887. PubMed PMID: 37644361.
Bernard JY, Poncet L, Saïd M, Yang S, Dufourg MN, Gassama M, Charles M-A. Temps d’écran de 2 à 5 ans et demi chez les enfants de la cohorte nationale Elfe. Bull Epidemiol Hebdo. 2023;6:98-105.
Kamga Fogno AW, Rouquette A, Gronfier C, Bernard JY, Plancoulaine S, group Ss. Associations between screen use, outdoor time/daylight exposure and sleep changes during the first COVID-19 lockdown in French children from the ELFE and EPIPAGE2 birth cohorts. CNS Neurosci Ther. 2023;29(6):1649-56. Epub 2023/02/23. doi: 10.1111/cns.14128. PubMed PMID: 36807866; PubMed Central PMCID: PMC10173720.
Poncet L, Said M, Gassama M, Dufourg MN, Muller-Riemenschneider F, Lioret S, Dargent-Molina P, Charles MA, Bernard JY. Sociodemographic and behavioural factors of adherence to the no-screen guideline for toddlers among parents from the French nationwide Elfe birth cohort. Int J Behav Nutr Phys Act. 2022;19(1):104. Epub 20220812. doi: 10.1186/s12966-022-01342-9. PubMed PMID: 35962431; PubMed Central PMCID: PMC9373389.
Martinot P, Bernard JY, Peyre H, De Agostini M, Forhan A, Charles MA, Plancoulaine S, Heude B. Exposure to screens and children's language development in the EDEN mother-child cohort. Sci Rep. 2021;11(1):11863. Epub 20210608. doi: 10.1038/s41598-021-90867-3. PubMed PMID: 34103551; PubMed Central PMCID: PMC8187440.
Chen B, Bernard JY, Padmapriya N, Ning Y, Cai S, Lanca C, Tan KH, Yap F, Chong YS, Shek L, Godfrey KM, Saw SM, Chan SY, Eriksson JG, Tan CS, Muller-Riemenschneider F. Associations between early-life screen viewing and 24 hour movement behaviours: findings from a longitudinal birth cohort study. Lancet Child Adolesc Health. 2020;4(3):201-9. Epub 2020/02/01. doi: 10.1016/S2352-4642(19)30424-9. PubMed PMID: 32004497.
Bernard JY, Rifas-Shiman SL, Cohen E, Lioret S, de Lauzon-Guillain B, Charles MA, Kramer MS, Oken E. Maternal religion and breastfeeding intention and practice in the US Project Viva cohort. Birth. 2020;47(2):191-201. Epub 2019/12/31. doi: 10.1111/birt.12477. PubMed PMID: 31884716; PubMed Central PMCID: PMC7245542.
Bernard JY, Pan H, Aris IM, Moreno-Betancur M, Soh SE, Yap F, Tan KH, Shek LP, Chong YS, Gluckman PD, Calder PC, Godfrey KM, Chong MF, Kramer MS, Karnani N, Lee YS. Long-chain polyunsaturated fatty acids, gestation duration, and birth size: a Mendelian randomization study using fatty acid desaturase variants. Am J Clin Nutr. 2018;108(1):92-100. Epub 2018/06/08. doi: 10.1093/ajcn/nqy079. PubMed PMID: 29878044; PubMed Central PMCID: PMC6038907.
Bernard JY, Padmapriya N, Chen B, Cai S, Tan KH, Yap F, Shek L, Chong YS, Gluckman PD, Godfrey KM, Kramer MS, Saw SM, Muller-Riemenschneider F. Predictors of screen viewing time in young Singaporean children: the GUSTO cohort. Int J Behav Nutr Phys Act. 2017;14(1):112. Epub 2017/09/06. doi: 10.1186/s12966-017-0562-3. PubMed PMID: 28870219; PubMed Central PMCID: PMC5584344.
Bernard JY, Armand M, Peyre H, Garcia C, Forhan A, De Agostini M, Charles MA, Heude B, Group EM-CCS. Breastfeeding, Polyunsaturated Fatty Acid Levels in Colostrum and Child Intelligence Quotient at Age 5-6 Years. J Pediatr. 2017;183:43-50 e3. Epub 2017/01/14. doi: 10.1016/j.jpeds.2016.12.039. PubMed PMID: 28081886.
Galéra C, Bernard JY, van der Waerden J, Bouvard MP, Lioret S, Forhan A, De Agostini M, Melchior M, Heude B, Group EM-CCS. Prenatal Caffeine Exposure and Child IQ at Age 5.5 Years: The EDEN Mother-Child Cohort. Biol Psychiatry. 2016;80(9):720-6. Epub 2015/10/08. doi: 10.1016/j.biopsych.2015.08.034. PubMed PMID: 26444074.
