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Physical education and leisure-time sport reduce overweight and obesity: a number needed to treat analysis

International Journal of Obesity (2019) | Download Citation



School-based physical education (PE) and organised leisure-time sports participation (LTSP) represent important physical activity opportunities for children. We examined the preventive effect of increased PE as well as LTSP on overweight and obesity (OW/OB) in school children.


Longitudinal data from children attending 10 primary schools in the Danish municipality of Svendborg, comprising 6 intensive PE (270 min/week) and 4 control (90 min/week) schools were assessed. Age- and sex-specific cut-offs for body mass index (BMI) determined OW/OB status. Associations between OW/OB status and school type (intensive PE or control) or LTSP were investigated using mixed, multilevel logistic regression models. Significant parameter estimates were converted into number needed to treat statistics (NNT).


In total, 1009 children (53.3% female; mean age 8.4 ± 1.4 years) were included in the analysis, with 892 children (52% female) being normal weight (NW) at baseline. Eighteen (NNT = 17.1; 95% CI [11.0, 226.1]) children attending an intensive PE school for 2 years, resulted in one fewer case of OW/OB compared with attendance at a normal PE school. For NW children, prevention of one case of OW/OB requires 36 (NNT = 35.8; 95% CI [25.1, 596.3]) children to participate in intensive PE for 2 years in comparison with normal PE. LTSP over 2 years may prevent OW/OB if 15 children participate in one LTSP session/week, 9 in two LTSP sessions/week and 8 in three LTSP sessions/week; for normal weight children, 25 children had to participate in one LTSP session/week, 16 in two LTSP sessions/week and 14 in three LTSP sessions/week.


We provide the first NNT estimates of school-based PE and LTSP to prevent the onset of OW/OB. PE, and separately, LTSP seem to have both a protective and a treatment effect against OW/OB in children.

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The authors gratefully acknowledge the work of numerous students and PhD students who have participated in the data collection for the CHAMPS Study-DK. We thank children, parents and teachers in the schools involved in the project, and we are grateful for the cooperation with The Svendborg Project, Sport Study Sydfyn and The Municipality of Svendborg. We also acknowledge members of the CHAMPS Study-DK not listed as co-authors of this paper: C Christiansen, E Jespersen and C Franz.

Author information


  1. School of Psychology and Exercise Science, Murdoch University, Murdoch, WA, 6150, Australia

    • Yvonne C. Learmonth
    • , Jeffrey J. Hebert
    •  & Timothy J. Fairchild
  2. Faculty of Kinesiology, University of New Brunswick, Fredericton, Canada

    • Jeffrey J. Hebert
    •  & Niels Wedderkopp
  3. Centre of Research in Childhood Health, Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark

    • Niels Christian Møller
    • , Heidi Klakk
    •  & Niels Wedderkopp
  4. University College Lillebælt, Odense, Denmark

    • Heidi Klakk
  5. Orthopedic Department, Hospital of Southern Jutland, Esbjerg, Denmark

    • Niels Wedderkopp


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Funding for the study is provided by The TRYG Foundation, University College Lillebaelt, University of Southern Denmark, The Nordea Foundation, The IMK Foundation, The Region of Southern Denmark, The Egmont Foundation, The A.J. Andersen Foundation, The Danish Rheumatism Association, Østifternes Foundation, Brd. Hartmann’s Foundation, TEAM Denmark, The Danish Chiropractor Foundation and The Nordic Institute of Chiropractic and Clinical Biomechanics.

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The authors declare that they have no conflict of interest.

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Correspondence to Yvonne C. Learmonth.

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