Abstract
This study presents the prevalence and likelihood of US individuals younger than 18 years meeting recommendations on time spent sleeping, in physical activity, and in front of screens.
Sleep, physical activity, and screen-time behaviors among adolescents are risk factors for physical health (eg, obesity), mental and emotional health, behavioral outcomes (eg, tobacco use), and performance-based outcomes (eg, academic achievement).1,2,3 Accordingly, it is recommended that children (age 6-12 years) sleep 9 to 12 hours and adolescents (age 14-18 years) sleep 8 to 10 hours a night and that both groups accumulate at least 1 hour of moderate-intensity or vigorous-intensity aerobic physical activity and limit screen time (ie, exposure to all screen-based digital media) to less than 2 hours within a 24-hour period.3,4 Meeting recommendations for all 3 behaviors may have a greater association with health outcomes than meeting any 1 recommendation in isolation. However, the prevalence and likelihood of US adolescents meeting these recommendations in combination across various sociodemographic factors is unknown.
Methods
Cross-sectional data from the 2011, 2013, 2015, and 2017 cycles of the Youth Risk Behavior Surveillance Survey were used. Multiple imputation by chained equations were used to address missing data issues and to derive the final analytic data set including all participants. Determination of recommendations met was based on the behavioral targets defined.
Prevalence estimates and the adjusted log odds of concurrently achieving the recommendations for sleep, physical activity, and screen time were estimated by sex and in strata by age, race/ethnicity, body mass index, risky behaviors, reported asthma diagnosis, and presence of depression symptoms. The study protocol was reviewed by The University of Texas Health Science Center at Houston Committee for the Protection of Human Subjects and received exempt status. Data are deidentified, and informed consent from participants was not required. All analyses were conducted using Stata version 15.1 (StataCorp), and results were considered significant at the .05 level (2-sided).
Results
A total of 59 397 participants were included in the unweighted data set (Table). Overall, 5.0% (95% CI, 4.6-5.4) of US adolescents met recommendations for sleep, physical activity, and screen time concurrently. Stratified analysis by sex revealed a lower proportion of girls (3.0% [95% CI, 2.7%-3.3%]) than boys (7.0% [95% CI, 6.5%-7.5%]) met all 3 behavioral recommendations. The observed sex differences were consistent across all other subgroups of interest.
Table. Prevalence and Adjusted Relative Odds of Meeting Recommendations for Sleep, Screen Time, and Physical Activity Among US Youth per Youth Risk Behavior Surveillance Survey, 2011-2017.
| Characteristic | Sample Size, No. | Youth Meeting Sleep, Physical Activity, and Screen-Time Recommendations | |||||
|---|---|---|---|---|---|---|---|
| Weighted % (95% CI) | Adjusted Odds Ratio (95% CI) | ||||||
| Overall | Female | Male | Overall | Female | Male | ||
| Overall | 59 397 | 5.0 (4.6-5.4) | 3.0 (2.7-3.3) | 7.0 (6.5-7.5) | NA | NA | NA |
| Age, y | |||||||
| ≤14 | 6659 | 5.8 (4.9-6.6) | 3.7 (2.9-4.6) | 8.0 (6.6-9.5) | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| 15 | 14 837 | 5.6 (4.9-6.3) | 3.4 (2.8-4.0) | 7.8 (6.7-8.8) | 0.91 (0.74-1.12) | 0.90 (0.68-1.19) | 0.92 (0.70-1.19) |
| 16 | 15 120 | 4.6 (4.1-5.2) | 2.6 (2.0-3.1) | 6.7 (5.8-7.5) | 0.77 (0.63-0.94) | 0.70 (0.52-0.95) | 0.80 (0.63-1.01) |
| 17 | 14 309 | 3.4 (3.0-3.8) | 1.9 (1.5-2.3) | 4.9 (4.1-5.6) | 0.54 (0.44-0.66) | 0.50 (0.36-0.70) | 0.56 (0.43-0.72) |
| ≥18 | 8472 | 6.8 (6.0-7.6) | 4.3 (3.3-5.2) | 8.8 (7.6-10.1) | 1.09 (0.89-1.35) | 1.21 (0.87-1.68) | 1.05 (0.81-1.37) |
| Race/ethnicity | |||||||
| Non-Hispanic white | 32 687 | 6.3 (5.8-6.8) | 3.8 (3.3-4.2) | 8.9 (8.1-9.6) | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Non-Hispanic black | 8244 | 2.0 (1.6-2.5) | 1.3 (0.9-1.7) | 2.8 (2.0-3.5) | 0.31 (0.25-0.39) | 0.34 (0.23-0.49) | 0.30 (0.23-0.40) |
| Hispanic/Latino | 12 838 | 4.0 (3.5-4.4) | 2.5 (2.0-3.0) | 5.4 (4.7-6.1) | 0.66 (0.58-0.75) | 0.71 (0.55-0.92) | 0.64 (0.54-0.75) |
| Non-Hispanic Asian | 2015 | 2.5 (1.6-3.5) | 0.9 (0.2-1.7) | 4.0 (2.2-5.8) | 0.37 (0.25-0.55) | 0.22 (0.10-0.50) | 0.44 (0.37-0.71) |
| Othera | 3613 | 4.8 (3.8-5.8) | 2.5 (1.7-3.4) | 7.1 (5.4-8.8) | 0.81 (0.66-1.01) | 0.74 (0.51-1.09) | 0.84 (0.65-1.09) |
| Weight categories | |||||||
| Normal weightb | 39 855 | 5.5 (5.1-5.9) | 3.4 (3.0-3.7) | 7.8 (7.1-8.4) | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Underweightc | 1728 | 4.4 (2.9-5.9) | 2.4 (0.7-4.1) | 5.7 (3.6-7.7) | 0.72 (0.50-1.03) | 0.72 (0.34-1.50) | 0.72 (0.48-1.09) |
| Overweightd | 9467 | 4.4 (3.7-5.1) | 2.4 (1.8-3.1) | 6.4 (5.2-7.6) | 0.80 (0.68-0.95) | 0.79 (0.61-1.03) | 0.81 (0.65-0.99) |
| Obesee | 8347 | 3.3 (2.8-4.0) | 1.5 (1.0-2.0) | 4.6 (3.7-5.5) | 0.57 (0.47-0.69) | 0.48 (0.33-0.71) | 0.59 (0.48-0.73) |
| Tobacco use | |||||||
| Nonuser | 47 542 | 4.8 (4.5-5.2) | 3.1 (2.8-3.4) | 6.7 (6.1-7.3) | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Userf | 11 855 | 5.6 (5.0-6.4) | 2.3 (1.6-3.0) | 7.7 (6.7-8.7) | 1.27 (1.07-1.50) | 0.99 (0.69-1.44) | 1.32 (1.08-1.61) |
| Alcohol use | |||||||
| Nonuser | 38 707 | 5.2 (4.8-5.6) | 3.4 (3.0-3.8) | 7.0 (6.3-7.6) | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Userf | 20 690 | 4.6 (4.1-5.1) | 2.2 (1.9-2.6) | 7.0 (6.2-7.8) | 0.93 (0.81-1.07) | 0.72 (0.56-0.93) | 1.04 (0.86-1.35) |
| Marijuana use | |||||||
| Nonuser | 46 162 | 5.3 (4.9-5.6) | 3.2 (2.8-3.5) | 7.4 (6.8-8.0) | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Userf | 13 235 | 4.1 (3.6-4.6) | 2.2 (1.7-2.7) | 5.7 (4.9-6.5) | 0.81 (0.69-0.96) | 1.06 (0.79-1.43) | 0.75 (0.61-0.92) |
| Asthma | |||||||
| Never diagnosed | 19 172 | 5.0 (4.6-5.5) | 2.7 (2.5-3.2) | 7.2 (6.5-7.8) | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Diagnosedg | 34 288 | 4.9 (4.4-5.4) | 3.2 (2.8-3.7) | 6.6 (5.9-7.4) | 1.00 (0.89-1.13) | 1.16 (0.98-1.39) | 0.94 (0.81-1.08) |
| Depression | |||||||
| No symptoms | 41 631 | 6.1 (5.7-6.6) | 3.8 (3.4-4.3) | 7.9 (7.3-8.5) | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Symptomsh | 17 766 | 2.3 (2.0-2.6) | 1.7 (1.3-2.0) | 3.5 (2.9-4.1) | 0.44 (0.38-0.50) | 0.46 (0.36-0.57) | 0.43 (0.36-0.52) |
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); NA, not applicable.
Includes Native Hawaiian/Pacific Islander and non-Hispanic individuals of multiple race/ethnicities.
Normal weight is defined as a body mass index (BMI) percentile from the 5th to less than the 85th percentile.
Underweight is defined as a BMI percentile equal to or less than the 5th percentile.
Overweight is defined as a BMI percentile from the 85th to less than the 95th percentile.
Obesity is defined as a BMI percentile equal to or greater than the 95th percentile.
Tobacco, alcohol, and marijuana use are defined as reporting use at least once in the last 30 days.
Asthma diagnosis is defined as reporting having ever been told by a physician or nurse that he or she has asthma.
Depression is defined as a patient reporting feeling so sad or hopeless almost every day for a 2-week period or longer within the last 12 months that he or she stopped doing some usual activities.
There were significant disparities in the odds of meeting all 3 behavioral recommendations by age (for participants of both sexes who were 16 years old: adjusted odds ratio [aOR], 0.77 [95% CI, 0.63-0.94] and 17 years old: aOR, 0.54 [95% CI, 0.44-0.66], compared with those 14 years and younger), race/ethnicity (non-Hispanic black participants: aOR, 0.31 [95% CI, 0.25-0.39]; Hispanic/Latino participants: aOR, 0.66 [95% CI, 0.58-0.75]; non-Hispanic Asian participants: aOR, 0.37 [95% 0.25-0.55], compared with non-Hispanic white participants), body mass index (participants who were overweight: aOR, 0.80 [95% CI, 0.68-0.95]; participants with obesity: aOR, 0.57 [95% CI, 0.47-0.69], compared with participants of normal weight), marijuana use (aOR, 0.81 [95% CI, 0.69-0.96]), and depressive symptoms (aOR, 0.44 [95% CI, 0.38-0.50]). Girls who reported alcohol use had 28% (95% CI, 7%-44%; aOR, 0.72 [95% CI, 0.56-0.93]) lower odds of meeting all the recommendations concurrently compared with girls who did not use alcohol.
Conclusions
Study findings indicate that only 5% of US high school students (3% of girls; 7% of boys) spend the optimal time sleeping and being physically active while limiting screen time, with important disparities shown by vulnerable subgroups. These findings demonstrate the need for future studies clarifying the role of parenting style and home environment. The multicomponent nature of these behaviors supports investigating systems-level interventions aimed at coordinating behavior changes at multiple levels of the social-ecological model.5 Future research should also evaluate the synergistic associations between these behaviors, particularly if spending the optimum time in 1 behavior leads to more or less time in the other behaviors.
Self-reported data used in these analyses may be biased. This supports the need for device-based evaluations of the 24-hour cycle, including differences in behavioral profiles on weekdays and weekends.
Finally, findings have high clinical relevance, and suggest that physicians should be encouraged to use the 5 A’s Behavior Change Framework and ask about these behaviors at every patient encounter, advise patients and parents on the importance of the behaviors, assess potential barriers to assist with counseling on best practices, and arrange for follow-up to reassess behaviors or refer to specialists as needed.6
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