A total of 2.939 abstracts were identified through the initial search process. Upon review, 31 full papers were retrieved for further review by two investigators. Of those 31 papers, 12 studies met the inclusion criteria. outlines the flow of the search process and the number of articles that were identified at each stage of the process.
Flow chart of the search process.
Three studies [22
] focused only on SB, 1 study was a PA intervention [27
], 6 studies [20
] were combined SB and PA interventions, and 2 studies [32
] targeted SB, PA, and diet. Of the 12 studies, 8 were conducted in the US, 3 in Europe (including the UK, France, and the Netherlands), and 1 in Australia. The majority (7 out of 12) of the studies were conducted in a school setting, while 2 were conducted in a clinic, 1 in community centers, 1 conducted in both community centers and schools, and 1 other was carried out in convenient locations, which included clinics, libraries, and schools.
summarizes the study design and characteristics, while summarizes the outcome measurements focused on SB and anthropometrics and also key findings of each study. The definition of SB varied across the studies. Listed here are all the forms of SB that were measured: time spent watching TV and videotapes, playing video games, doing homework, reading, listening to music, using a computer, playing a musical instrument, doing artwork or crafts, talking with parents, playing quiet games indoors, and attending classes or club meetings. Due to the diversity in study design, study duration, setting, population, and measurement outcomes of the interventions, a quantitative synthesis of the evidence was not possible. Therefore, a qualitative assessment of the current evidence stratified by targeted behaviors is presented.
Description of interventions to reduce sedentary behavior in youth.
Evaluation of interventions to reduce sedentary behavior in youth.
3.1. Sedentary Behavior Studies
Three studies [22
] focused on reducing SB in school-aged children. Escobar-Chaves et al. [26
] aimed to reduce TV and other media consumption in families with children of ages 6 to 9 years in Houston, Tex, US. One hundred one families were randomized to either the 6-month intervention, which included a 2-hour workshop and 6 bimonthly newsletters, or a control group. The parents and children also worked together to develop a plan in which alternative activities could be done by the child and family in place of SB. At 6-month followup, there was a trend toward reducing media consumption in the intervention group; however, these results were not statistically significant. The intervention did find a positive impact on proxy behaviors hypothesized to lead to media use reductions, which are also recommended by the American Academy of Pediatrics, such as not having a TV in the child's bedroom.
] randomly assigned 3rd and 4th graders in 1 of 2 public elementary schools in San Jose, Calif, US to receive an 18-lesson, 6-month classroom curriculum to reduce TV, videotape, and video game use. The curriculum, which was taught by the regular classroom teachers, included self-monitoring and self-reporting of media use, followed by a TV turnoff, in which children were challenged not to use media for 10 days. After the turnoff challenge, the children were encouraged to follow a 7-hour/week budget of media use. Each household also received an electronic TV time manager, which monitored and bugeted TV/video use for each household member. Newsletters designed to motivate parents to help their children maintain their TV watching limits were also distributed. At the end of the intervention, children in the intervention group had decreases in multiple anthropometric measures, which included BMI, triceps skinfold thickness, waist circumference, and waist to hip ratio (P
< 0.002), compared to the control group. In addition, reported TV use was lower in the intervention group (8.80 versus 14.46 hours/week; P
< 0.001); however, no significant changes were reported in video tape and video game use.
Another study conducted by Robinson and borzekowski [23
] consisted of a randomized controlled trial among 3rd and 4th graders in San Jose, Calif, US in 2 public elementary schools (n
= 181). The intervention was an 18-lesson classroom curriculum focused on reducing screen media exposure. Components of the intervention included children becoming aware of the role TV, videotapes, and video games play in their lives, a TV turnoff in which children attempted to watch no TV/videotapes or play video games for 10 days, children learning how to budget their media use, and participants helping their peers at another school to reduce their media use. Newsletters were also distributed to the parents. Children in the intervention school significantly decreased their weekday TV viewing (1.14 versus 1.96 hours/day; P
< 0.001) and weekday (0.19 versus 0.52 hours/day; P
< 0.05) and Saturday video game playing (0.31 versus 0.9 hours/day; P
< 0.05) compared to controls. Greater effects were found among boys (P
= 0.05) and more adult-supervised children (P
3.2. Physical Activity Study
One study that focused solely on PA in school-aged children was identified. Slootmaker et al. [27
] randomized 87 13-to-17 year olds in Amsterdam, The Netherlands to receive either a single brochure with PA recommendations or an accelerometer and access to web-based tailored PA advice for 3 months. When a user logged into the website and uploaded his/her PA score, the website provided individualized PA feedback based on the current PA score and personally adapted suggestions to promote daily PA. At 5-month followup, time spent doing SB was significantly reduced in boys (−1,801 minutes/week; P
= 0.04). No SB changes were observed in girls.
3.3. Sedentary Behavior and Physical Activity Studies
Six studies [20
] that targeted both SB and PA were identified. Epstein et al. [21
] randomized obese children of ages 8 to 12 years from 61 families to 1 of 3 treatment groups: (1) increasing exercise (Exercise), (2) decreasing SB (Sedentary), or (3) both increasing exercise and decreasing SB (Combined). All groups received similar information (distributed through manuals) about the benefits of increased PA and the negative effects of SB; however, the groups differed in the types of activities that were reinforced. The Sedentary group was reinforced for decreasing the amount of time they engaged in certain SB; these SBs included media use, imaginative play, talking on the phone, and playing board games. Participants in the Exercise group were reinforced for increasing PA, while those in the Combined group were reinforced for both decreasing SB and increasing PA. Weekly treatment meetings were also conducted for both the parent and child. At 6-month followup, the Sedentary group had greater decrease in percentage overweight than did the Exercise or Combined groups (−18.7 versus −10.3 versus −8.7; P
= 0.026) and greater decrease in percentage of body fat (−4.7 versus −1.3; P
Another study by Epstein et al. 2001 [20
] randomly assigned 67 families with an obese child between ages of 8 to 12 years to 1 of 2 treatment groups: (1) increasing PA (Increase) or (2) reducing SB and increasing PA (Combined). The treatment program consisted of 16 weekly meetings, followed by 2 biweekly meetings and 2 monthly meetings during a 6-month intensive program. At 6-month followup, boys showed significantly better percentage of overweight changes in the Combined group than girls (−15.8% versus −1.0%; P
< 0.001), with no significant differences in the Increase group for boys or girls (−9.3% versus −7.6%). Boys also adhered to the treatment better than girls (P
Jones et al. [28
] recruited 12 middle schools in central Texas to participate in a 1.5-year randomized clinical trial focused on improving bone health mainly through promoting the increase of PA. A total of 718 6th grade girls participated in the intervention, which consisted of a 16-session health curriculum to promote increased weight-bearing PA and consumption of calcium-rich foods. A physical education component was also included, which consisted of high-impact activities. Relative to the girls in the control group, the intervention group significantly reduced daily TV and video minutes (−12.11 minutes/day; P
= 0.05). Total daily minutes of sedentary activity were significantly lower for intervention students relative to controls (mean difference between groups = −17 minutes; P
Robinson et al. [29
] conducted a randomized controlled trial with 61 8-to-10-year-old African-American (AA) girls and their parents. The 12-week intervention consisted of after-school dance classes and a 5-lesson family-based intervention delivered in participants' homes to reduce media use. At followup, the girls in the intervention group had trends towards lower BMI (adjusted difference = −0.32
; 95% CI −0.77 to 0.12) and waist circumference (adjusted difference = −0.63
cm; 95% CI −1.92 to 0.67) and reduced TV, videotape, and video game use (adjusted difference = −4.96 hours/week; 95% CI −11.41 to 1.49).
Salmon et al. [30
] randomized, by class, 311 children from 3 government schools in low socioeconomic areas of Melbourne, Australia into one of four conditions: (1) behavioral modification (BM); (2) fundamental movement skills (FMS); (3) combined BM and FMS (BM/FMS); (4) control (usual curriculum). Each of the intervention conditions consisted of 19 lessons promoting PA and decreasing SB. The BM lessons were delivered in the classroom, while the FMS lessons were delivered in PA facilities, which focused on teaching participants physical skills while emphasizing enjoyment and fun. The combined group received both the BM and FMS lessons. There was a significant intervention effect from baseline to postintervention on BMI in the BM/FMS group compared to the control group (−1.88
< 0.01), which was maintained at 6- and 12-month followup (−1.53
< 0.05). The BM group reported highest levels of TV viewing compared to the other groups (239.9 minutes/week; P
Simon et al. [31
] conducted a 4-year randomized controlled trial with a cohort of 954 middle-school adolescents in eastern France. The multilevel intervention focused on influencing intrapersonal, social, and environmental determinants of PA and SB through informational sessions, social support by parents, peers, teachers, and PA instructors and by providing environmental conditions for PA to encourage students to apply the knowledge and skills they learned. The study is currently on going; thus, data reported here were collected 6 months into the intervention. After 6 months of the intervention, high SB (<3 hours/day) was reduced in both girls and boys (OR = 0.54 and 0.52; P
< 0.001) in the intervention group compared to the control.
3.4. Sedentary Behavior, Physical Activity, and Diet Studies
Two studies [32
] focused on modifying SB, PA, and diet. Gortmaker et al. [32
] randomized 5 out of 10 middle schools in Massachusetts to receive an interdisciplinary intervention over the course of 2 school years. The intervention, Planet Health
, was included in the existing school curriculum of 4 subjects and physical education classes. The sessions focused on decreasing TV viewing, decreasing consumption of high-fat foods, increasing fruit and vegetable intake, and increasing moderate to vigorous PA. Over the 2-year intervention period, obesity prevalence among girls in the intervention schools decreased compared to controls (OR = 0.47; P
= 0.03), while no differences were observed in boys. The number of hours of TV/video use was reduced in both boys and girls in the intervention group compared to the control group (adjusted difference between groups for boys and girls = −0.40 and −0.58 hours/day; P
Sacher et al. [33
] recruited 116 obese children in the UK to be randomly assigned to receive the Mind, Exercise, Nutrition, Do it (MEND) program, a multicomponent community-based intervention. This intervention consisted of 18 2-hour group educational and PA sessions held twice weekly in sports centers and schools, in which both parents and children attended. These sessions were followed by a 12-week free family swimming pass. At 6 months, participants in the intervention group had a reduced waist circumference z
-score (−0.37; P
< 0.0001) and BMI z
-score (−0.24; P
< 0.0001) compared to controls. Significant differences in SB were observed between the intervention and control groups (15.9 versus 21.7 hours/week; P
= 0.01). The significant decreases in waist circumference and BMI in the intervention group were sustained up to 9 months after participants completed the educational and PA sessions.