Dr. Ian Janssen, Ph.D. (Queen's)

Dr. Ian Janssen
Professor (Tenured) and Canada Research Chair in Physical Activity and Obesity
Area of Expertise: 
Physical Activity Epidemiology
Contact Information
613-533-6000 x78631
KHS 301W

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 pre-school 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 training opportunities

Opportunities exist for graduate students (M.Sc. and Ph.D.) 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 environment), and 4) the outcomes of these behaviours (e.g., cardiometabolic risk factors).  Although internal funding is available, prospective graduate students and postdocs are encouraged to apply to the Ontario Graduate Scholarship Program, the Heart and Stroke Foundation, the Canadian Institute of Health Research (CIHR), and other agencies that provide support for research trainees. Highly qualified applicants will receive strong support.

Current funding

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

Recent publications


* underlined authors represent students that I have supervised

A complete list of publications and access to PDF copies of many of these publications can be found at my ResearchGate profile.

Janssen I.  Active play: an important physical activity strategy in the fight against childhood obesityCan J Public Health.  2014;105(1):e22-e27.

Clarke J, Janssen ISporadic and bouted physical activity and the metabolic syndrome in adultsMed Sci Sports Exerc.  2014;46:76-83.

Janssen ICrime and perceptions of safety in the home neighborhood are independently associated with physical activity among 11-15 year oldsPrev Med.  2014;66:113-117.

Carson V, Rosu A, Janssen IA cross-sectional study of the environment, physical activity, and screen time among young children and their parentsBMC Public Health.  2014;14:61.  (doi: 10.1186/1471-2458-14-61)

Kukaswadia A, Pickett W, Janssen ITime since immigration and ethnicity as predictors of physical activity among Canadian youth: a cross-sectional study. PLoS ONE. 2014;9(2):e89509.

Gray CE, Larouche R, Barnes JD, Colley RC, Bonne JC, Arthur M, Cameron C, Chaput JP, Faulkner G, Janssen I, Kolen AM, Manske SR, Salmon A, Spence JC, Timmons BW, Tremblay MS. Are we driving our kids to unhealthy habits? Results from the Active Healthy Kids Canada 2013 Report Card on Physical Activity for Children and YouthInt J Environ Res Public Health. 2014;11:6009-6020.

Gray CE, Barnes JD, Cowie Bonne J, Cameron C, Chaput JP, Faulkner G, Janssen I, Katzmarzyk PT, Kolen AM, Manske SR, Salmon A, Spence JC, Timmons BW, Tremblay MS.  Results from Canada’s 2014 report card on physical activity for children and youth.  J Phys Act Health.  2014;11(Supp 1):S26-S32. 

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

Gee ME, Pickett W, Janssen I, Campbell NR, Birtwhistle R.  Validity of self-reported blood pressure control in people with and without diabetes attending a primary care centerBlood Pressure Control. 2014;19:19-25.

Kobayashi LC, Janssen I, Richardson H, Lai AS, Spinelli JJ, Aronson KJ.  A case-control study of lifetime light intensity physical activity and breast cancer riskCancer Causes & Control. 2014;25:133–140.   

Lawson J, Janssen I, Bruner M, Hossain A, Pickett W.  Asthma incidence in a national longitudinal sample of adolescent Canadians: a prospective cohort study.  BMC Pulm Med.  2014;14:51

Janssen I, Carson V, Lee I-M, Katzmarzyk PT, Blair SN.  Years of life gained due to leisure-time physical activity in the U.S.  Am J Prev Med.  2013;44:23–29. 

Carson V, Tremblay MS, Spence JC, Timmons BW, Janssen IThe Canadian Sedentary Behaviour Guidelines for the Early Years (zero to four years of age) and screen time among children from Kingston, OntarioPaediatr Child Health.  2013;18:25-28.

Laxer RE, Janssen IThe proportion of excessive fast food consumption attributable to the neighbourhood food environment among youth living within 1 km of their schoolAppl Physiol Nutr Metab.  2014;39(4):480-486. 

Janssen IThe public health burden of obesity in CanadaCan J Diabetes. 2013;37:90-96.  

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

Bouchard DR, Porneala B, Janssen I, Langlois MF, Baillargeon JP, Pencina M, D’Agostino Sr RB, Fox CS, Meigs JB,  Hivert MF. Risk of type 2 diabetes is associated with cumulative excess weight exposure from mid-thirties to mid-fifties in the Framingham Offspring StudyJ Diabetes Complications.  2013;27(3):214-218. 

Gotay CC, Katzmarzyk PT, Janssen I, Dawson MY, Aminoltejari K, Bartley NL.  Updating the Canadian obesity maps: an epidemic in progressCan J Public Health.  2013;104(1):e64-68.

Gropp KM, Janssen I, Pickett W.  Active transportation to school in Canadian youth: should injury be a concern?  Inj Prev.  2013;19:64-67.  

Héroux M, Onywera V, Tremblay MS, Adamo KB, Lopez Taylor J, Jáuregui Ulloa E, Janssen I. The relation between aerobic fitness, muscular fitness and obesity in children from three Countries at different stages of the physical activity transitionISRN Obes.  2013; Article ID 134835.

Seliske L, Pickett W, Rosu A, Janssen IThe number and type of food retailers surrounding schools and lunchtime eating behaviours of studentsInt J Behav Nutr Phys Act.  2013;10:19.

Colley RC, Garriguet D, Janssen I, Saunders TJ, Carson V, Tremblay MS. The association between accelerometer-measured patterns of sedentary time and health risk in children and youth: results from the Canadian Health Measures SurveyBMC Public Health.  2013;13:200.

Onywera VO, Héroux M, Jáuregui Ulloa E, Adamo KB, López Taylor J, Janssen I, Tremblay MS.  Adiposity and physical activity among children in countries at different stages of the physical activity transition: Canada, Mexico and Kenya.  African Journal for Physical, Health Education, Recreation and Dance.  2013;19(1):134-144.

Colley RC, Garriguet D, Adamo KD, Carson C, Janssen I, Timmons BW, Tremblay MS.  Physical activity and sedentary behavior during the early years in Canada: A cross-sectional studyInt J Behav Nutr Phys Act.  2013;10:54. 

Clarke J, Janssen I.  Is the frequency of weekly moderate-to-vigorous physical activity associated with the metabolic syndrome in Canadian adults?  Appl Physiol Nutr Metab.  2013;38:773-778. 

Browning HF, Laxer RE, Janssen I.  Food and eating environments in Canadian schoolsCan J Diet Pract Res.  2013;74(4):160-166.

Medina C, Barquera S, Janssen IValidity and reliability of the International Physical Activity Questionnaire among Mexican adultsPan Am J Public Health.  2013;34:21-28.

Kobayashi LC, Janssen I, Richardson H, Lai AS, Spinelli JJ, Aronson KJ.  Moderate-to-vigorous intensity physical activity across the life course and risk of pre- and post-menopausal breast cancerBreast Cancer Res Treat.  2013;139(3):851-861. 

Janssen I, Wong SL, Colley RC, Tremblay MT.  The fractionalization of physical activity throughout the week is associated with the cardiometabolic health of children and youthBMC Public Health.  2013;13:554. 

Laxer RE, Janssen IThe proportion of youths’ physical inactivity attributable to neighborhood built environment featuresInt J Health Geogr2013;12:31. 

Janssen I, Medina C, Barquera S.  Screen time in Mexican children: findings from the 2012 ENSANUT.   Salud Publica Mex. 2013;44:484-491.

Gillis L, Tomkinson G, Olds T, Moreira C, Christie C, Nigg C, Cerin E, Van Sluijs E, Stratton G, Janssen I, Dorovolomo J, Reilly J, Mota J, Zayed K, Kawalski K, Andersen LB, Carrizosa M, Tremblay M, Chia M, Hamlin M, Eleri Thomas N, Maddison R, Biddle S, Gorely T, Onywera V, Van Mechelen W.  Research priorities for child and adolescent physical activity and sedentary behaviours: an international perspective using a twin-panel Delphi procedure. Int J Behav Nutr Phys Act.  2013;10:112   

Safdie M, Aburto NJ, Lévesque L, Janssen I, Campirano‐Núñez F, López‐Olmedo N, Aburto T, Rivera JA.  Impact of a school‐based intervention program on obesity risk factors in Mexican childrenSalud Publica Mex.  2013;55(suppl 3):S347-S387.

Huynh Q, Craig W, Janssen I, Pickett W.  Exposure to public natural space as a protective factor for emotional well-being among young people in CanadaBMC Public Health.  2013;13:407.

Pinkerton B, Rosu A, Janssen I, Pickett W.  Active transportation safety features around schools in CanadaInt J Environ Res Public Health 2013;10:5711-5725  (doi: 10.3390/ijerph10115711).

Medina C, Janssen I, Campos I, Barquera S.  Increasing trends of physical inactivity among Mexican adults: results from the Mexican National Health and Nutrition survey (ENSANUT) 2006 and 2012BMC Public Health.  2013;13:1063. 

Gee ME, Pickett W, Janssen I, Johnson JA, Campbell NR.  Health behaviors for hypertension management in people with and without coexisting diabetesJ Clin Hypertens.  2013;15(6):389-396.