Key Takeaways
Sedentary behaviour matters: Every extra hour of television raised the odds of being overweight or obese by about 10 %.
Physical activity is protective—but not equally for everyone: More days of 60minute physical activity lowered obesity odds overall, yet this relationship disappeared for Latina/o students.
Latina/o youth are at greater risk: After adjusting for other factors, identifying as Latina/o increased the odds of overweight/obesity by 20 %.
Gender gap: Males were significantly more likely than females to be overweight or obese, even after controlling for activity and screen time.
Game time not a clear villain: Once other variables were considered, video/computergame hours no longer predicted weight status.
What Did the Study Do?
Using the 2011 national Youth Risk Behavior Surveillance System (YRBSS) dataset (n = 15,503 highschool students), the authors examined how three behaviours—days of moderatetovigorous physical activity (PA), television viewing, and videogame/computer use—along with gender and Latina/o ethnicity, relate to Body Mass Index (BMI) categories. Logistic regression tested both main effects and whether the PA–weight link differed by ethnicity.
Results Highlight
Prevalence: Roughly 30 % of respondents were classified as overweight or obese; slightly fewer than onethird identified as Latina/o.
Main effects:
Physical activity: Each additional active day reduced the odds of excess weight (Adjusted Odds Ratio [AOR] = 0.95, p < .001).
TV viewing: Each additional hour increased the odds (AOR = 1.11, p < .001).
Grade level: Students in lower grades were marginally more likely to be overweight/obese.
Gender: Being female lowered risk (AOR = 0.69, p < .001).
Ethnicity: Latina/o status raised risk (AOR = 1.20, p < .001).
Interaction effect: Among non-Latinos, students with above-median PA had 4 percentage points lower overweight/obesity prevalence than their less-active peers (26.4 % vs 30.5 %). For Latinos, PA made no meaningful difference (32.7 % vs 32.3 %).
Discussion — Why It Matters
The findings reaffirm that screen time, especially passive TV watching, is a potent behavioural risk factor, likely combining reduced movement with cues to overconsume caloriedense foods. The unequal benefit of physical activity raises urgent equity questions: cultural food norms, limited access to safe recreation, and structural barriers such as underresourced schools may blunt the protective power of exercise in Latina/o communities. The authors call for community-tailored interventions—for example, multilevel programmes like the Stanford GOALS study that pair PA promotion with family and neighbourhood supports—to disrupt entrenched obesity trends.
Limitations to Keep in Mind
Self-reported height/weight and behaviours may misclassify some students.
BMI cannot distinguish muscle from fat, though it remains practical for large surveys.
Cross-sectional design prevents firm cause-and-effect conclusions; more longitudinal and experimental studies are needed.
Implications for Practice
Cut the TV time: School and community programmes should target television viewing specifically, not just generic “screen time.”
Rethink one-size-fits-all PA strategies: Standard activity boosts may help non-Latino youth more than Latina/o youth; culturally responsive approaches that also address diet, family habits, and neighbourhood safety are vital.
Track weekdays and weekends: Future surveys should capture full-week screen behaviour to refine recommendations.
Bottom line: Combating youth obesity demands a dual focus—reducing passive screen habits and increasing quality physical activity—while simultaneously recognising and addressing the unique social and cultural contexts that shape health outcomes for Latina/o adolescents.
Full Article:
Marttinen, R., Vernikoff, L., Phillips, S., & Fletcher, N. (2017). Physical activity, screen time, and obesity: A statistical inquiry into Latino/a youth. Californian Journal of Health Promotion, 15(1), 27-35. https://doi.org/10.32398/cjhp.v15i1.1886
This blog post was written with the assistance of AI to support clarity and accessibility. It is intended to help disseminate and discuss research findings with a broader audience. However, for the most accurate and reliable information—including conclusions and practical applications—please refer to the original peer-reviewed publication on which this blog is based. The peer-reviewed article remains the most authoritative source.