This meta-analysis reviewed 67 studies that evaluated the effectiveness of interventions targeting sedentary behavior at reducing BMI in children and adolescents. It found that such interventions resulted in a small but statistically significant reduction in BMI. Moderator analysis found that interventions were more effective at reducing BMI for younger children, interventions lasting longer than 6 months, and interventions conducted in educational settings. Risk of bias was low to unclear for most studies included.

1. Liane B. Azevedo1; Jonathan Ling2; Istvan Soos2; Louisa Ells1; Shannon
Robalino3; Greg Atkinson1
1Teesside University; 2Sunderland University; 3Newcastle University
Effectiveness of sedentary
behaviour interventions on
BMI reduction in children and
adolescents: a meta-analysis

2. Introduction
Ø Sedentary behaviour definition:
Activities that do not increase energy expenditure
substantially above the resting level (1.0 to 1.5 METs) and
includes activities such as sitting, lying down, and
watching television and other forms of screen-based
entertainment1.
1: Pate et al. (2008) Exerc Sport Sci Rev.

3. Department of Health, 20111
Early years (under 5s):
Ø All under 5s should minimise the amount of time
spent being sedentary (being restrained or sitting)
for extended periods (except time spent
sleeping).
Children and young people:
Ø People should minimise the amount of time spent
being sedentary (sitting) for extended periods.
ACSM recommendation: limit television viewing and
video game playing to less than two hours per day2,3.
Public Health Recommendations
1: Department of Health (2011). Start Active, Stay Active: A report on physical activity from the four home countries’ Chief Medical
Officers.
2: Tremblay et al. (2011) Int J Behav Nutr Phys Act.
3: Strasburger & Hogan (2013) American Academy of Pediatrics Committee on Public Education. Children, adolescents, and the media.
Pediatrics 2013

4. Introduction
High levels of sedentary behaviour in children are associated
with:
Ø Increased risk of obesity (i.e. TV viewing) 1,2
Ø Low self-esteem2
Ø Decrease in academic achievement2
Ø Lower fitness levels2
Ø Poor motor coordination3
Ø Poor mental health4
Ø Unhealthy diet5
1: Rey-López et al. (2008). Nutrition, Metabolism and Cardiovascular Diseases; Lee et al (2014) Int J Environ Res Public Health.
2014
2: Tremblay et al. (2011). IJBNPA
3: Smith et al (2015). Int J Behav Nutr Phys Act.
4: Asare & Danquah (2015). Child Adolesc Psychiatry Ment Health.
5: Hobbs et al (2015). Br J Sports Med.

5. Why focus on BMI
Ø Strong relationship between
screen time and weight gain1
Ø Sedentary behaviour might be
associated with increase energy
intake (e.g. snacking)1,2
Ø Most common measurement of
sedentary behaviour
interventions in children.
Introduction
1. Monteiro & Victora (2005); Rey-López et al. (2008); Lee et al (2014)
2. Must et al. (2009)
3: Borghese et al. (2015): J Nutr Sci. ; Borghese et al. (2014) Appl Physiol Nutr Met; De Craemer et al. (2012), Obesity Review

6. Davison & Birch (2001). Childhood overweight: a contextual model and recommendations for
future research. Obesity Reviews 2(3):159-171
Ecological model of predictors of
childhood overweight

7. Wahi et al., 2011
N=6
Van Grieken et al., 2012
N=14
Liao et al., 2014
N=25

8. Why another one?
Ø Latest update July 2012
Ø 21 new studies have been published since the
last review
Ø 19 studies before July 2012 were not included
in previous reviews.
Ø Different inclusion criteria
Ø Van Grieken et al., 2011 not included studies
with overweight and obese participants
Ø Liao et al., 2014 excluded studies in which BMI
was adjusted for covariates

9. Aim
Primary aim:
Ø The aim of this meta-analysis is to summarize and compare the effect
of interventions that target sedentary behavior (e.g. TV viewing, video
game) on BMI in children.
Secondary aim:
Ø Explore the impact of several moderator variables on intervention
effectiveness to reduce BMI:
• Child age range: pre-school (0 to 4 years old); children (4 to 10 years
old) and adolescents (11 to 17 years old).
• Duration of intervention (<6 months; >6 months)
• Intervention setting (educational, non-educational, combined)
• Type of intervention (single or multiple intervention)
• Population (mixed or overweight/obese)
• Study quality

10. Methods
Ø Inclusion criteria:
• Intervention studies (randomised and non-
randomised) with a control group
• Children aged 0 to 17 years old
• Intervention should targeting sedentary activities
but also included if they target other behaviours
(e.g. diet and physical activity)
• Objectively measured weight and height

11. Methods
Search strategy
Ø Databases:
• Medline (Ovid); Cochrane (includes DARE, CDSR,
CENTRAL); Embase (Ovid); CINAHL (Ebsco); PsycInfo
(Ovid); ERIC (ProQuest); SPORTDiscus (Ebsco)
Ø Searches in June and July 2013 followed by two update
searches – October 2013 and March 2015
Data extraction
Ø Study design
Ø Population
Ø Intervention (e.g. type,duration, frequency, delivery
setting…);
Ø Outcome (e.g. BMI, SB, PA)
Risk of bias assessment
Ø Cochrane Collaboration tool for Assessing Risk of Bias
Ø 7 domains: sequence generation, allocation concealment,
blinding of participants and personnel, blinding of outcome
assessment, incomplete outcome data, selective outcome
reporting and 'other'.

12. Methods
Ø Data analysis:
Ø Means and standard deviations (SD) of BMI or BMI z-score
were used for continuous outcomes.
Ø Standardised mean difference (SMD)
SMD = Difference in mean outcome between groups
Standard deviation of outcome among
Ø In case the study reported data for boys and girls they
were entered separately into the meta-analysis.
Ø Studies with more than one intervention arm the data was
combined using pair-wise comparison with control group.

13. Initial database search
n= 7607
Duplication removed n= 1842
Abstracts screened
N=5765
Full- text assessed for eligibility
N= 187
Articles selected for data extraction
N= 67
Abstracts excluded: met one of the
exclusion criteria: n= 5578
Papers excluded after
evaluation of full text
N= 120
Results

14. Risk of Bias
0% 10% 20% 30% 40% 50% 60%
Unclear
High risk of
bias
Low risk of
bias

15. Studyname Statistics for each study Mean and 95% CI
Standard Weight Lower Upper
Mean error (Random) limit limit p-Value
Andrade et al.2014 -0.010 0.008 256.99 -0.025 0.005 0.191
Bacardi- Gascon et al.2012-0.740 0.194 24.14 -1.120 -0.360 0.000
Backlund et al.2011 -0.300 0.371 7.07 -1.027 0.427 0.419
Birken et al.2012 0.010 0.117 56.81 -0.220 0.240 0.932
Breslin et al. 201; boys 0.130 0.187 25.85 -0.236 0.496 0.486
Breslin et al. 2012; girls0.210 0.192 24.53 -0.167 0.587 0.275
Campbell et al.2013 -0.020 0.082 95.27 -0.180 0.140 0.806
De Coen et al.2011 -0.030 0.037 193.44 -0.102 0.042 0.412
Dennison et al. 2004 -0.360 0.440 5.07 -1.222 0.502 0.413
Dzewaltowski et al.2010-0.100 0.073 109.74 -0.242 0.042 0.169
Elder et al.2013 0.000 0.195 23.86 -0.382 0.382 1.000
Epstein et al. 2008 -0.110 0.510 3.79 -1.110 0.890 0.829
Esfarjani et al. 2012 -0.400 0.252 14.86 -0.894 0.094 0.112
Ezendam et al.2013 0.160 0.145 40.08 -0.125 0.445 0.271
Faith et al. 2001 -1.300 1.252 0.64 -3.753 1.153 0.299
Fitzgibbon et al. 2006 -0.020 0.179 28.00 -0.370 0.330 0.911
Fitzgibbon et al. 2010 -0.110 0.079 99.14 -0.265 0.045 0.164
Fitzgibbon et al. 2012 0.070 0.156 35.65 -0.235 0.375 0.653
Fitzgibbon et al.2004 -0.090 0.084 91.58 -0.255 0.075 0.285
Folta et al.2013 -0.057 0.010 254.01 -0.077 -0.037 0.000
French et al. 2010 0.064 0.100 72.29 -0.132 0.260 0.523
Gentile et al. 2009 0.100 0.161 33.50 -0.216 0.416 0.535
Goldfield et al. 2013 -0.900 0.504 3.88 -1.887 0.087 0.074
Goran et al.2005; boys 0.150 0.028 216.37 0.095 0.205 0.000
Goran et al.2005; girls -0.070 0.028 215.65 -0.126 -0.014 0.014
Grydeland et al.2014 -0.100 0.057 141.11 -0.212 0.012 0.080
Habib-Mourad et al.20140.180 0.158 34.89 -0.129 0.489 0.253
Haines et al. 2013 -0.400 0.202 22.50 -0.795 -0.005 0.047
Harrison et al. 2006 -0.080 0.041 181.86 -0.160 -0.000 0.050
Hughes et al.2008 0.030 0.041 181.86 -0.050 0.110 0.462
Kalarchian et al. 2013 -1.220 0.360 7.49 -1.926 -0.514 0.001
Kipping et al.2008 0.100 0.186 25.97 -0.265 0.465 0.591
Lawlor et al. 2011 -0.020 0.028 216.44 -0.075 0.035 0.476
Lloyd et al. 2012 -0.950 1.452 0.47 -3.795 1.895 0.513
Lubans et al. 2012 -0.190 0.263 13.72 -0.705 0.325 0.470
Martínez-Andrade et al. 20140.230 0.156 35.65 -0.075 0.535 0.139
McCallum et al. 2006 -0.200 0.383 6.66 -0.950 0.550 0.601
Nemet et al.2013 -0.970 0.200 22.81 -1.362 -0.578 0.000
Neumark-Sztainer et al. 2010-0.080 0.122 53.52 -0.319 0.159 0.512
Ni Mhurchu et al.2009 0.050 0.166 31.93 -0.275 0.375 0.763
O'Connor et al. 2011 0.090 0.506 3.85 -0.902 1.082 0.859
Ostbye et al. 2012 -0.010 0.071 113.22 -0.149 0.129 0.888
Patrick et al.2013 -0.133 0.059 137.68 -0.248 -0.019 0.023
Pbert et al.2013 -0.090 0.380 6.76 -0.834 0.654 0.813
Peralta et al.2009 -0.200 0.306 10.25 -0.800 0.400 0.514
Puder et al. 2011 -0.070 0.064 126.58 -0.195 0.055 0.272
Reilly et al. 2006 0.050 0.059 136.15 -0.066 0.166 0.399
Reinehr et al. 2010 -1.700 0.276 12.51 -2.241 -1.159 0.000
Robinson et al. 2003 -0.320 0.227 18.06 -0.765 0.125 0.159
Robinson et al.1999 -0.450 0.143 41.25 -0.730 -0.170 0.002
Robinson et al.2010 0.040 0.115 58.79 -0.185 0.265 0.728
Roemmich et al. 2004 -0.080 0.075 105.79 -0.227 0.067 0.286
Saelens et al. 2002 -0.100 0.016 244.95 -0.131 -0.069 0.000
Salmon et al. 2008 -1.037 0.326 9.07 -1.676 -0.397 0.001
Shelton et al. 2007 -1.160 0.724 1.90 -2.578 0.258 0.109
Simon et al. 2008 -0.260 0.089 84.71 -0.435 -0.085 0.004
Singh et al. 2009; boys 0.000 0.077 103.20 -0.150 0.150 1.000
Singh et al. 2009; girls -0.100 0.077 103.20 -0.250 0.050 0.191
Smith et al. 2014 0.000 0.120 54.85 -0.235 0.235 1.000
Spruijt-Metz et al. 2008 -0.020 0.007 257.58 -0.034 -0.006 0.005
Taveras et al.2010 -0.260 0.335 8.62 -0.917 0.397 0.438
Taveras et al.2011 -0.210 0.145 40.04 -0.495 0.075 0.149
Todd et al. 2008 -0.440 0.145 40.04 -0.725 -0.155 0.002
Toruner et al. 2010 -0.300 0.319 9.49 -0.925 0.325 0.346
van Nassau et al.2014 0.030 0.028 216.33 -0.025 0.085 0.286
Veldhuis et al.2009 -0.160 0.222 18.84 -0.595 0.275 0.471
Verbestel et al.2012 -0.560 0.101 71.07 -0.758 -0.362 0.000
Wafa et al. 2011 -0.090 0.158 34.66 -0.400 0.220 0.569
Wen et al.2012 -0.290 0.135 45.22 -0.555 -0.025 0.032
Williamson et al. 2012; boys-0.034 0.040 185.34 -0.111 0.043 0.390
Williamson et al. 2012; girls-0.035 0.016 244.37 -0.067 -0.003 0.030
-0.064 0.014 -0.091 -0.038 0.000
-4.00 -2.00 0.00 2.00 4.00
Favours A Favours B
Favours intervention Favours comparator
67 studies
71 entries
N=30,116

16. Studyname Statisticsforeachstudy Meanand95% CI
Standard Weight Lower Upper
Mean error (Random) limit limit p-Value
Bacardi- Gasconetal.2012 -0.740 0.194 14.74 -1.120 -0.360 0.000
Backlundetal.2011 -0.300 0.371 5.95 -1.027 0.427 0.419
Breslinetal.2012boys 0.130 0.187 15.36 -0.236 0.496 0.486
Breslinetal.2012girls 0.210 0.192 14.88 -0.167 0.587 0.275
Dennisonetal.2004 -0.360 0.440 4.47 -1.222 0.502 0.413
Dzewaltowski etal.2010 -0.100 0.073 28.14 -0.242 0.042 0.169
Elder etal.2013 0.000 0.195 14.63 -0.382 0.382 1.000
Esfarjani etal.2012 -0.400 0.252 10.67 -0.894 0.094 0.112
Ezendametal.2013 0.160 0.145 19.46 -0.125 0.445 0.271
Faithetal.2001 -1.300 1.252 0.63 -3.753 1.153 0.299
Fitzgibbonetal.2006 -0.020 0.179 16.09 -0.370 0.330 0.911
Fitzgibbonetal.2010 -0.110 0.079 27.39 -0.265 0.045 0.164
Fitzgibbonetal.2012 0.070 0.156 18.36 -0.235 0.375 0.653
Fitzgibbonetal.2004 -0.090 0.084 26.77 -0.255 0.075 0.285
Gentileetal.2009 0.100 0.161 17.77 -0.216 0.416 0.535
Goldfieldetal.2013 -0.900 0.504 3.52 -1.887 0.087 0.074
Goranetal.2005;boys 0.150 0.028 32.21 0.095 0.205 0.000
Goranetal.2005;girls -0.070 0.028 32.19 -0.126 -0.014 0.014
Grydelandetal.2014 -0.100 0.057 29.84 -0.212 0.012 0.080
Habib-Mouradetal.2014 0.180 0.158 18.15 -0.129 0.489 0.253
Hainesetal.2013 -0.400 0.202 14.11 -0.795 -0.005 0.047
Harrisonetal.2006 -0.080 0.041 31.32 -0.160 -0.000 0.050
Kalarchianetal.2013 -1.220 0.360 6.26 -1.926 -0.514 0.001
Kipping etal.2008 0.100 0.186 15.40 -0.265 0.465 0.591
Lloydetal.2012 -0.950 1.452 0.47 -3.795 1.895 0.513
Lubansetal.2012 -0.190 0.263 10.07 -0.705 0.325 0.470
Martínez-Andradeetal.2014 0.230 0.156 18.36 -0.075 0.535 0.139
McCallumetal.2006 -0.200 0.383 5.66 -0.950 0.550 0.601
Nemetetal.2013 -0.970 0.200 14.23 -1.362 -0.578 0.000
Neumark-Sztainer etal.2010 -0.080 0.122 22.17 -0.319 0.159 0.512
Ni Mhurchuetal.2009 0.050 0.166 17.32 -0.275 0.375 0.763
Pbertetal.2013 -0.090 0.380 5.73 -0.834 0.654 0.813
Peraltaetal.2009 -0.200 0.306 8.07 -0.800 0.400 0.514
Puder etal.2011 -0.070 0.064 29.13 -0.195 0.055 0.272
Reinehr etal.2010 -1.700 0.276 9.40 -2.241 -1.159 0.000
Robinsonetal.2003 -0.320 0.227 12.22 -0.765 0.125 0.159
Robinsonetal.1999 -0.450 0.143 19.74 -0.730 -0.170 0.002
Robinsonetal.2010 0.040 0.115 23.02 -0.185 0.265 0.728
Salmonetal.2008 -1.037 0.326 7.32 -1.676 -0.397 0.001
Sheltonetal.2007 -1.160 0.724 1.81 -2.578 0.258 0.109
Simonetal.2008 -0.260 0.089 26.15 -0.435 -0.085 0.004
Singhetal.2009;boys 0.000 0.077 27.69 -0.150 0.150 1.000
Singhetal.2009;girls -0.100 0.077 27.69 -0.250 0.050 0.191
Smithetal.2014 0.000 0.120 22.39 -0.235 0.235 1.000
Taverasetal.2010 -0.260 0.335 7.02 -0.917 0.397 0.438
Todd etal.2008 -0.440 0.145 19.45 -0.725 -0.155 0.002
Toruner etal.2010 -0.300 0.319 7.59 -0.925 0.325 0.346
Veldhuisetal.2009 -0.160 0.222 12.58 -0.595 0.275 0.471
Wenetal.2012 -0.290 0.135 20.60 -0.555 -0.025 0.032
-0.147 0.035 -0.217 -0.078 0.000
-4.00 -2.00 0.00 2.00 4.00
FavoursA FavoursB
Favours intervention Favours comparator
49 studies
N=17,495

17. Group or
Subgroup
Meta-analysis
(95%CI)
Heterogeneity Between
group
differences p
value
Number of
studies
(entries)
Overall change
SMD
-0.064 (-0.091
to -0.038)
75% <0.001 71
Overall change
BMI (kg/m2)
-0.147 (-0.217
to -0.078)
76% <0.001 49
Intervention
SB -0.204 (-0.354
to -0.053)
75 % <0.05 6
SB + PA -0.030 (-0.090
to 0.03)
NS 11
SB + PA + Diet -0.074 (-0.108
to -0.041)
<0.001 54
Setting
Educational -0.022 (-0.060
to -0.015)
75% NS 27
Non-
educational
-0.161 (-0.218
to -0.105)
<0.001 25
Combined -0.059 (-0.109
to -0.010)
<0.05 19

18. Results
Ø No significant differences between groups were
found:
• For different age groups (pre-school; children and
adolescents).
• Duration of intervention (<6 months; >6 months)
• Population (mixed; overweight/obese)
• Study quality

19. Discussion
Studies BMI SDS BMI (kg/m2) Significance
Wahi et al. 2011
N=6
-0.10 (95%CI: -0.28 to
0.09)
NS
Van Grieken et al. 2012
N= 14
-0.14 (95%CI: -0.23 to
-0.05)
P<0.05
Liao et al. 2014
N= 25
-0.07 (95% CI: -0.14 to
-0.01)
P<0.05
This study -0.064 (95% CI: -0.091
to -0.038)
N=67
-0.147 (95% CI: -0.217
to -0.078)
N=49
P<0.001
Results were statistically significant but were they clinically relevant?

20. Discussion
Studies Reference value Health improvement
Reinehr & Andler 2004
Reinehr et al., 2004
BMI z ≥ 0.5 Improvement in insulin
sensitivity and resistance
and atherogenic profile
Kirk et al., 2005 BMI z ≥ 0.15 Improvement in
cholesterol (total, LDL
and HDL) and insulin
Ford et al., 2012 BMI z ≥ 0.25 Improvement in
cardiometabolic risk
Kolsgaard et al., 2011 BMI z ≥0.0 Improvement in insulin
and cholesterol levels
Goldsmith et al., 2013 Changes in weight of
-7.55 kg to +3.9 kg
Sufficient from
overweight or obese child
to become normal weight
after 1 year

21. 9 year old children
Reduce 0.25 BMIz = 0.5 BMI Kg/m2
0.15 BMI kg/m2 = 0.07 BMI z
16 year old children
Reduce 0.25 BMIz = 0.39 BMI Kg/m2
0.15 BMI kg/m2 = 0.1 BMI z

22. Summary
Ø Sedentary behaviour interventions are associated with small
but significant improvement in BMI and BMI z.
Ø The clinical relevance of this findings remains unclear.
Ø Interventions which target only SB or target SB + PA + diet
and delivered in non-educational (e.g. home) or combined
(e.g. home and school) settings appear to be more effective.
Ø There was a high heterogeneity between studies possibly
caused by clinical or methodological differences between
studies.

23. Conclusion
Ø Child obesity is multifactorial and
involve several contexts that interact
with each other1 and it is unlikely that
targeting only one behaviour will
promote change in child weight status.
Ø Interventions targeting child obesity
should still consider including a SB as
this might:
Ø Increase total energy expenditure
(TEE)1
Ø Reduce a higher consumption of
unhealthy food2
Ø Be associated with improvement in
other health outcomes (self-esteem,
academic achievement, fitness level,
motor coordination and mental
health). 1: Deheeger et al. (1997) Int J Obes Relat Metab Disord
2: Diez & Gortmaker (1985) Pediatrics

24. Thank you for your
attention