Ian Janssen, PhD

PhD (Queen's University)

MSc (Queen's University)

BPHE(Hon) (Laurentian University)


Contact Information

Email:  ian.janssen@queensu.ca

Telephone:  613-533-6000 x78631

Office:  KHS 301W


Undergraduate Courses

HLTH 323 - Epidemiology


Research Summary

My population-based research program examines the role that physical inactivity and obesity play in the development of poor health in both child and adult populations.  Ongoing research projects within my laboratory examine the following issues:

  • Surveillance of the physical inactivity and obesity levels of the population.
  • To examine the role of physical activity on health in preschool children, school-aged children and youth, and adults including research on:
    • The dose-response relation between physical activity and health
    • Whether different domains of physical activity influence health in a different manner (active play, active transportation, physical education, etc.)
    • To what extent the intensity of physical activity is important for health
    • The influence of sedentary behaviour on health
    • To examine the influence of the built environment on the physical activity, sedentary behaviour, and eating behaviours of children and youth


Graduate Student Opportunities

Opportunities exist for undergraduate students, MSc students, PhD students, and postdoctoral fellows to develop expertise in epidemiological aspects of physical activity, sedentary behaviour, and obesity.  This includes studying: 1) the measurement of these behaviours, 2) the surveillance of these behaviours, 3) the determinants of these behaviours (e.g., built and social environments), and 4) the physical, mental, and social health outcomes of these behaviours.  Internal funding is available to support highly qualified applicants.


Current Funding


Canadian Institutes of Health Research (CIHR), Heart and Stroke Foundation, and the Public Health Agency of Canada


Examples of Recent Publications

The list provided below provides 10 examples of recent publications.  In my career I have published over 240 journal articles and 20 book chapters.  A complete list of these publications and PDF copies of these publications can be found at my ResearchGate profile.  Collectively, these publications have been cited >35,000 times in other publications.


Note that author names that are underlined are of research trainees and students that I have supervised.  The expectation and norm in my laboratory is that graduate students will publish their thesis research in the scientific literature (i.e., at least 1 publication for MSc students, at least 4 publications for PhD students).


Borgundvaag E, Janssen I.  Objectively measured physical activity and mortality risk in American adults.  Am J Prev Med.  2017;52:e25-e31. 


McMillan R, McIsaac M, Janssen I.  Family structure as a correlate of organized sport participation among youth.  PLoS One.  2016;11(2):e0147403.


Robson J, Janssen I.  Intensity of sporadic and bouted physical activity and the metabolic syndrome in adults.  PeerJ.  2015;3:e1437 


Ferrao T, Janssen I.  Parental encouragement is positively associated with outdoor active play outside school hours among 7-12 year olds.  PeerJ.  2015;3:e1463 


Warkentin T, Borghese MM, Janssen I.  Associations between weight-related teasing and psychosomatic symptoms by weight status among school-aged youth.  Obes Sci Pract. 2017;3:44-50. 


Medina C, Barquera S, Katzmarzyk PT, Janssen I.  Physical activity during recess among 13-14 year old Mexican girls.  BMC Pediatr. 2015;15:17 


Saleh D, Janssen I.  Interrelationships among sedentary time, sleep duration, and the metabolic syndrome in adults.   BMC Public Health. 2014;14:666. 


Kukaswadia A, Pickett W, Janssen I.  Influence of country of birth and ethnicity on BMI among Canadian youth: a national survey. CMAJ Open.  2014;2(3):E145-E152. 


Carson V, Rosu A, Janssen I.  A cross-sectional study of the environment, physical activity, and screen time among young children and their parents.  BMC Public Health.  2014;14:61. 


Button B, Trites S, Janssen I.  Relations between the school physical environment and school social capital with student physical activity levels. BMC Public Health.  2013;13:1191.